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How to cite this thesis
Surname, Initial(s). (2012) Title of the thesis or dissertation. PhD. (Chemistry)/ M.Sc. (Physics)/ M.A. (Philosophy)/M.Com. (Finance) etc. [Unpublished]: University of Johannesburg. Retrieved from: https://ujdigispace.uj.ac.za (Accessed: Date). TAXONOMIC STUDIES ON NEMATODES FROM BOTSWANA AND THE MONONCHIDA OF SOUTHERN AFRICA
by
SANDRA DE BRUIN
Thesis
presented in partial fulfilment
of the requirements for the degree of
DOCTOR IN PHILOSOPHY
in
NEMATOLOGY
in the
FACULTY OF NATURAL SCIENCES
at the
RAND AFRIKAANS UNIVERSITY
Promoter: ProfJ. Heyns November 1992 In memory ofmy father One ofthe mostperplexing problems facing the practising nematologist, is to be aware ofand to categorize the ever-increasing plethora ofnematode taxa.
Annen Charles Tarjan Acknowledgements
I would like to express my gratitude to:
Professor Juan Heyns who gave me the opportunity to undertake this study, and to
complete it under his competent guidance.
Antoinette Swart, Annelize Botha, Wilma Liebenberg and Johan Kruger for their
friendship, support and assistence.
My Mother, for always being available, lending an unselfish hand whenever needed.
My husband, Choppie and children, Dieter, Marinda and Christie, for their
continuous love, support and encouragement.
My Heavenly Father - to Him all the glory. Summary
This thesis consists of two parts. The first part deals with terrestrial nematodes of
Botswana (excluding the Mononchida) obtained during a survey done by A. Coomans and
J. Heyns during July and August 1989. Thirty five species are dealt with, of which two are new to science. The species found, represent twenty seven genera, mainly of the
Dorylaimida, but also of the Araeolaimida, Enoplida, Rhabditida and the Tylenchida. The two new species which are comprehensively described and illustrated are: Mesodorylaimus usitatoides spec. nov. and Proleptonchus dieted spec. nov. Of the thirty three known species, three are reported here for the first time from southern Africa viz. Aporcelaimellus papillatus (Bastian, 1865) Baqri & Khera, 1975, Neoactinolaimus thornei Chaturvedi &
Khera, 1979 and Panagrolaimus hygrophilus Bassen, 1940. These are fully described and illustrated. Many of the other species are also described and illustrated, but for some of the better known species only measurements, or measurements plus a brief description are given. Finally, a check list is presented for the free-living and plant parasitic nematodes known to occur in Botswana.
The second part deals with the Mononchida of southern Africa, and more specifically the genera Mononchus Bastian, 1865, Clarkus Jairajpuri, 1970, Coomansus Jairajpuri & Khan,
1977, lotonchus (Cobb, 1916) Altherr, 1950, Mylonchulus (Cobb, 1916) Altherr, 1953 and Granonchulus Andrassy, 1953. Descriptions, measurements and illustrations are given for nineteen known species. In addition, lotonchus loteniae spec. nov. is comprehensively described and illustrated. The taxonomy of several Mylonchulus species is discussed in detail to clear up the confusion and uncertainty which exsist in the literature about their identity. Dichotomous keys are presented for the identification of the southern African species of the above mentioned genera. Note
The greater part of this thesis has already been submitted as a series of articles in various journals. Chapters 1-6 of Part one, and Chapters 1-3 of Part two, correspond to these publications. Titles of publications, reference lists, etc. have been retained in these chapters. Only minor editorial changes have been made to maintain a certain uniformity of style in the thesis. Since every chapter thus is a self-contained unit, it was necessary to include reference lists also with the introduction. Contents
Part one
Page
List of Figures 1
ii List of Tables 4
iii Introduction 7
Chapter
1. Dorylaimida (Nematoda) from Botswana 11
2. One new and three known Dorylaimida species from Botswana 63
(Nematoda: Dorylaimida)
3. Further records of dorylaim species from Botswana 80
(Nematoda: DoryJaimida)
4. Cephalobidae (Nematoda: Rhabditida) from Botswana 102
5. A report on species of the orders Araeolaimida, Enoplida, Rhabditida 124
and Tylenchida (Nematoda) from Botswana
6. On the identity of Tubixaba parva Pretorius, Kruger & Heyns, 1987 and 147
Tubixaba tswanorum Nell & Heyns, 1987 (Nematoda: Aporcelaimidae)
7. A preliminary check list of the free-living and plant-parasitic 159
nematodes of Botswana Part two
List of Figures 2 ii List of Tables 4 jji Introduction 165
Page
1. Mononchida (Nematoda) of southern Africa: genera Mononchus 170
Bastian, 1865, Clarkus Jairajpuri, 1970 and Coomansus
Jairajpuri & Khan, 1977
2. Mononchida (Nematoda) of southern Africa: genus lotonchus 203
(Cobb, 1916) Altherr, 1950
3. Mononchida (Nematoda) of southern Africa: genera Mylonchulus 248
(Cobb, 1916)Altherr,1953 and Granonchulus Andrassy, 1958 List of Figures
Part one
Page
Ecumenicus monohystera (de Man, 1880) Thorne, 1974 52
Eudorylaimus diadematus (Cobb in Thorne & Swanger, 1936) Andrassy, 1959 53
Labronema mauritiense Williams, 1959 54
Discolaimus brevis Siddiqi, 1964 55
Discolaimus major Thorne, 1939 56
Aporcelaimellus adriaani Botha & Heyns, 1990 57
Aporcelaimellus micropunctatus Botha & Heyns, 1990 58
Aporcelaimellus papillatus (Bastian, 1865) Baqri & Khera, 1975 59
Aporcelaimellus parapapillatus Botha & Heyns, 1990 60
Mesodorylaimellus usitatoides spec. nov. 61
Prodorylaimus / Laimydorus species 62
Eudorylaimus amabilis (Jairajpuri, 1965) Siddiqi, 1966 77
Proleptonchus dieteri spec. nov. 78 ieptonchus transvaalensis Heyns, 1963 79
Tyleptus striatus Heyns, 1963 79
Neoactinolaimus thornei Chaturvedi & Khera, 1979 98
Nygolaimus anneckei Heyns, 1968 99
Solididens vulgaris (Thorne, 1930) Thorne, 1974 99
Axodorylaimellus caffrae (Kruger, 1965) Jairajpuri & Ahmad, 1980 99
Dorylaimellus directus Heyns, 1963 99
Dorylaimellus andrassyi Heyns, 1963 100
Tylencholaimus dorae Kruger, 1965 101
- 1 - Page
Seleborea mariannae (Andrassy, 1968) Andrassy, 1865 119
Seleborea eomplexa (Thorne, 1925) Andrassy, 1985 120
Seleborea reeurva (Heyns, 1969) Andrassy, 1985 120
Aerobeles singulus Heyns, 1969 121
Zeldia punetata (Thorne, 1925) Thorne, 1937 122
Zeldia species cf punetata (Thorne, 1925) Thorne, 1937 123
Chronogaster longieauda Heyns & Coomans, 1980 143
Neotobrilus diversipapillatus (Daday, 1905) Tsalolikhin, 1981 144
Neotobrilus species 144
Panagrolaimus species cf australis (Cobb, 1893) Sudhaus, 1976 145
Panagrolaimus hygrophilus Bassen, 1940 145
Hemieyeliophora species cf labiata Colbran, 1960 146
Tubixaba parva Pretorius, Kruger & Heyns, 1987 156;157;158
Part two
Mononehus aquatieus Coetzee, 1968 198
Mononehus truneatus Bastian, 1865 199
Clarkus sheri (Mulvey, 1967) Jairajpuri, 1970 200
Clarkus papillatus (Bastian, 1865) Jairajpuri, 1970 201
Coomansus parvus (de Man, 1880) Jairajpuri & Khan, 1977 202 lotonehus aeutus (Cobb, 1917) Andrassy, 1958 236;237 lotonehus geminus Heyns & Lagerwey, 1965 238;239 lotonehus litoralis Coetzee, 1967 240;241 lotonehus loteniae spec. nov. 242;243 lotonehus monhystera (Cobb, 1917) Jairajpuri, 1970 244
- 2 - Page lotonchus parabasidontus Mulvey & Jensen, 1967 245 lotonchus species A 246 lotonchus rinae Coetzee, 1967 247
Mylonchulus lacustris (Cobb, N.A. in Cobb, M.V., 1915) Andrassy, 1958 291
Mylonchulus minor (Cobb, 1893) Andrassy, 1958 292;293
Mylonchulus sigmaturus (Cobb, 1917) Altherr, 1953 294
Mylonchulus agriculturae Coetzee, 1966 295
Mylonchulus incurvus (Cobb, 1917) Andrassy, 1958 296
Mylonchulus brevicaudatus (Cobb, 1917) Altherr, 1954 297
Mylonchulus striatus (Thorne, 1924) Andrassy, 1958 298
Mylonchulus species A, Band C 299
Granonchulus subdecurrens Coetzee, 1966 300
- 3 - List of Tables
Part one
Page
Morphometric data of Ecumenicus monohystera (de Man, 1880) Thorne, 1974 44
and Eudorylaimus diadematus (Cobb in Thorne & Swanger, 1936)
Andrassy, 1959
Morphometric data of Labronema mauritiense Williams, 1959 45
Morphometric data of Discolaimus brevis Siddiqi, 1964 and Discolaimoides 46
bulbiferus (Cobb, 1906) Heyns, 1963
Morphometric data of some populations (females only) of Discolaimus 47
paramajor Coomans, 1966 and Discolaimus major Thorne, 1939
Morphometric data of Aporcelaimel/us adriaani Botha & Heyns, 1990 and 48
Aporcelaimel/us papil/atus (Bastian, 1865) Baqri & Khera, 1975
Morphometric data of Aporcelaimel/us micropunctatus Botha & Heyns, 1990 49
Morphometric data of Aporcelaimel/us parapapil/atus Botha & Heyns, 1990 50
Morphometric data of Mesodorylaimus usitatoides spec. nov. 51
Morphometric data of Seleborca mariannae (Andrassy, 1968) and Seleborca 118
complexa (Thorne, 1925) Andrassy, 1985
Morphometric data of Tubixaba parva Pretorius, Kruger & Heyns, 1987 155
Part two
Morphometric data of two populations of Mononchus aquaticus Coetzee, 1968 191
Morphometric data of several populations of Mononchus bel/us Andrassy, 1985 192;193
- 4 - Page
Morphometric data of Clarkus sheri (Mulvey, 1967) and Clarkus jugalis 194;195
(Coetzee, 1968) Jairajpuri, 1970
Morphometric data of Clarkus papillatus (Bastian, 1865) Jairajpuri, 1970 196
Morphometric data of South African populations of Coomansus parvus 197
(de Man, 1880) Jairajpuri & Khan, 1977
Morphometric data of lotonchus acutus (Cobb, 1917) Andrassy, 1958 229
Morphometric data of lotonchus geminus Heyns & Lagerwey, 1965 230
Morphometric data of lotonchus litoralis Coetzee, 1967 and lotonchus 231
shafii Khan & Jairajpuri, 1980
Morphometric data of lotonchus loteniae spec. nov. 232
Morphometric data of lotonchus monhystera (Cobb, 1917) Jairajpuri, 1970, 233
lotonchus jairi (Lordello, 1958) Clark, 1960 and totoncbus antedontoides
Coetzee, 1967
Morphometric data of lotonchus parabasidontus Mulvey & Jensen, 1967 234
Morphometric data of lotonchus rinae Coetzee, 1967 235
Morphometric data of some populations of Mylonchulus lacustris 278;279
(Cobb, N.A. in Cobb, M.V., 1915) Andrassy, 1958
Morphometric data of some populations of Mylonchulus minor 280;281
(Cobb, 1873) Andrassy, 1958
Morphometric data of some populations of Mylonchulus hawaiiensis 282
(Cassidy, 1931) Andrassy, 1958
Morphometric data of present populations of Mylonchulus minor 283
(Cobb, 1873) Andrassy, 1958
New distribution records and data on specimens of Mylonchulus minor 284
(Cobb, 1873) Andrassy, 1958
Habitat and localities of the specimens used for the description of 285
Mylonchulus minor (Cobb, 1873) Andrassy, 1958
- 5 - Page
Morphometric data of southern African populations of Mylonchulus 286
sigmaturus (Cobb, 1917) Altherr, 1953
Morphometric data of some populations of Mylonchulus brachyuris (Butschli, 287;288
1873) Altherr, 1953 and Mylonchulus agriculturae Coetzee, 1966
Morphometric data of three populations of Mylonchulus parabrachyurus 289
(Thorne, 1924) Andrassy, 1958
Morphometric data of Granonchulus subdecurrens Coetzee, 1966 290
- 6 - PART ONE Introduction
Botswana is a landlocked republic in southern Africa with an area of about 581,700 square kilometres (The New Encyclopaedia Brittanica p 941). It is surrounded by South Africa,
Namibia, Zambia and Zimbabwe.
The country has a mean altitude of 1009 metres (3,300 feet) and is almost entirely flat or gently undulating. The greater part is covered by Kalahari sands which cover about 84 % of the total area (The New Encyclopaedia Brittanica p 942 and Smit, 1970 p 14).
Some 17 % of Botswana's land surface is proclaimed and protected either as national parks or game reserves. In the north are found Chobe National Park, Moremi Wildlife
Reserve, Nxai Pan National Park and Makgadikgadi Pans Game Reserve. In the centre of the country lies the vast Central Kalahari Game Reserve, with Kutse Game Reserve tacked onto its southern border. In the south lies Mabuasehube Game Reserve and the Gemsbok
National Park (Main, 1990 p 195).
Soil types found in Botswana are, La. Desert soils, Sub desert soils, Calcimorphic non illuvial soils, Ferruginous tropical soils and Halimorphic soils. Desert soils and especially
Sub desert soils, are found over most of the surface area. In general, these soil types are characterized by their loose, sandy texture and have a low absorption capacity and conse quently a high rate of evaporation. Ferruginus tropical soils are found particularly in the
Chobe and eastern region. The other soil types that occur are either unfertile, or are found in areas that are not developed and about which there is little knowledge concerning their quality (Srnit, 1970 p 22-23).
- 7 - Botswana has a semi-arid climate. Temperatures vary from temperate to sub-tropical. In summer (October to March), temperatures rise to 38°C and in winter (April to September), there is frequent frost and temperatures fall below 10°C. Hot August winds carry sand from the Kalahari across the entire country.
The average annual rainfall is 460 mm. Most rain falls in heavy downpours between
December and the end of April, but the pattern, however, constantly changes. The
Okavango Delta always has more rain than the arid parts of the Kalahari (The New Ency clopaedia Brittanica p 942).
The main drainage system in Botswana is provided by the Okavango River, which, after flowing southeastward from the Angola border in the northwest, drains into a vast depres
sion to form the Okavango Swamp (The New Encyclopaedia Brittanica p 942). The
southern-most part of this swamp opens out into Lake Ngami. When the level of water in
Lake Ngami is high, there is an overflow via the Botletle river towards the extensive
Makarikari Salt Pan in the northeast. Farther north, the Chobe (sometimes known as the
Linyanti) river flows intermittently through some swampy country along part of the north
ern boundary on its way to join the Zambezi. The intermittently flowing Nossob and
Molopo rivers form the southern boundaries, while the Limpopo flows along part of the
southeastern border with the Transvaal (Jarrett, 1979 p 540).
The Kalahari is enormously varied, particularly with regard to the vegetation, which is
adapted to survive several years of drought (Main, 1987 p 46). Much of the country is
covered by Woodland Savanna (grassy parkland), in which species of Acacia predominate.
In the northeast the most characteristic vegetation cover consists of mopane or African
ironwood (Colophospermum mopane (Kirk ex Benth.) Kirk ex J. Leonard, mogonomo or
country almond (Berchemia discolor (Klozsch) Hemsley, and mokusi or Rhodesian teak
(Baikia plurijuga Harms), while morukuru or tamboti (Spirostachys africana Sonder) frequ-
- 8 - ently occurs in the central Kalahari (The new Encyclopaedia Brittanica p 942).
Other trees found in northern Botswana are i.a. the hyphaene palm tree ( Hyphaene benguellensis Welw.), sausage tree (Kigelia africana (Lam.) Benth.), large false mopane
(Guibourtia engleranum Henriques), and Albizia species (Coates Palgrave, 1977).
Two plants dominate the Delta's perennial swamps, viz. papyrus (Typha capensis (Rorhb.)
N.E. BR.), a giant sedge (type of grass) which grows naturally only in Africa, and the
willowy phoenix palm (Phoenix reclinata Jacq.) (Ross, 1987 p 115).
In the abundant grazing areas several varieties of grasses include love grass, panicum, crabgrass, and bristle grass. True forest, which occurs only on the banks of the Chobe
River, consists mainly of mukwa or bloodwood (Pterocarpus angolensis DC) and monato or
Rhodesian ash (Burkea africana Hook) (The New Encyclopaedia Brittanica p 942).
No comprehensive study has yet been undertaken on the nematode fauna of Botswana and
practically nothing is recorded in the literature. During July 1984, G. Stocker collected some nematodes in a mopane forest at Letlakane. This material was studied at the Rand
Afrikaans University, and resulted in the description of Xiphinema stockeri Kruger & Heyns,
1985, Siccaguttur mopanicum (Van Reenen & Heyns, 1986) Carbonell & Coomans, 1986 and Tubixaba tswanorum Nell & Heyns, 1987.
During July and August 1989, Professors A. Coomans and J. Heyns collected several soil and freshwater samples from the Chobe National Park, Moremi Wildlife Reserve as well as from the Okavango Swamps. These samples yielded specimens of about thirty nematode genera.
Heyns& Coomans (1991) reported on the Longidoridae obtained during this survey, whilst
- 9 - all the rest of the terrestrial species are dealt with in this study.
REFERENCES
COATES PALGRAVE, K. 1977. Iiees of Southern Africa. C. Struik Publishers Cape Town,
Johannesburg. 959 pp.
HEYNS, J. & COOMANS, A. 1991. Longidoridae from Botswana (Nematoda). Phytophy
lactica 23: 29-37.
JARRET, H.R. 1979. Africa. MacDonald and Evans. 598 pp.
MAIN, M. 1987. Kalahari. Life's Variety in Dune and Delta. Southern Book Publishers,
Johannesburg. 265 pp.
MAIN, M. 1990. Why go to Botswana? African Wildlife 44: 193-197.
ROSS, KAREN 1987. Jewel of the Kalahari. Okavango. Southern Book Publishers, Johan
nesburg. 256 pp.
SMIT, P. 1970. Botswana. Resources and Development. Africa Institute of South Africa.
256 pp.
The New Encyclopaedia Britannica 1986. 27: 941-942.
- 10 - CHAPTER
ONE Dorylaimida (Nematoda) from Botswana
ABSTRACT·
Thirteen nematode species are recorded from Botswana. Illustrations are given for Ecume nicus monohystera (de Man, 1880) Thorne, 1974; Eudorylaimus diadematus (Cobb in
Thorne & Swanger, 1936) Andrassy, 1959; Labronema mauritiense Williams, 1959; Disco laimus brevis Siddiqi, 1964; D. major Thorne, 1939; Aporcelaimellus adriaani Botha &
Heyns, 1990; A. micropunctatus Botha & Heyns, 1990; A. papillatus (Bastian, 1865) Baqri
& Khera, 1975; A. parapapillatus Botha & Heyns, 1990 and a specimen belonging to
Prodorylaimus or to Laimydorus. Measurements are given for the above mentioned species as well as for Discolaimium simplex Siddiqi, 1965 and Discolaimoides bulbiferus (Cobb,
1906) Heyns, 1963. A new Mesodorylaimus species viz. M. usitatoides is described.
Males are for the first time described for A. adriaani and A. micropunctatus. Discolaimus paramajor Coomans, 1966 is considered a possible synonym of D. major.
UITTREKSEL
Dorylaimida (Nematoda) vanaf Botswana
Dertien nematood spesies word uit Botswana aangemeld. IIlustrasies word gegee vir Ecumenicus monohystera (de Man, 1880) Thorne, 1974; Eudorylaimus diadematus (Cobb in Thorne & Swanger,
1936) Andrassy, 1959; Labronema mauritiense Williams, 1959; Discolaimus brevis Siddiqi, 1964;
D. major Thorne, 1939; Aporcelaimellus adriaani Botha & Heyns, 1990; A. micropunctatus Botha &
Heyns 1990; A. papillatus (Bastian, 1865) Baqri & Khera, 1975; A. parapapillatus Botha & Heyns,
1990 en 'n eksemplaar wat aan Prodorylaimus of aan Laimydorus behoort. Afmetings word vir al
- 11 - die bogenoemdes gegee, sowe/ as vir Discolaimium simplex Siddiqi, 1965 en Discolaimoides bulbi ferus (Cobb, 1906) Heyns, 1963. 'n Nuwe Mesodorylaimus spesie, naam/ik Mesodorylaimus usitatoides word beskryf. Mannetjies word vir die eerste keer beskryf vir A. adriaani en A. micro punctatus, Discolaimus paramajor Coomens, 1966 word as 'n moonttike sinoniem van D. major beskou.
INTRODUCTION
No comprehensive study has yet been undertaken on the nematode fauna of Botswana and apart from some isolated reports on nematodes from this region, nothing is recorded in the literature. During July and August 1989, A. Coomans and J. Heyns took several samples from the Chobe National Park, Moremi Wildlife Reserve as well as from the Okavango
Swamps. These samples yielded specimens of about thirty nematode genera. This mater ial is now being studied taxonomically at the Rand Afrikaans University, Johannesburg.
The present paper is the first of three parts reporting on the Dorylaimida obtained during this survey.
MATERIALS AND METHODS
Specimens were extracted by a modified sieving-sedimentation method (Loubser, 1985), killed by gentle heat, fixed in FAA, processed into glycerine by Thorne's slow method and mounted on permanent slides. Measurements and drawings were made with the aid of a
Zeiss Standard 18 research microscope equipped with a drawing tube. The body posture and all curved structures were measured along the median line. Oesophagus length as given in the Tables, was measured from the anterior end of the body to the base of the oesophagus. All measurements are in pm unless stated otherwise. Slide numbers refer to the nematode collection of the Department of Zoology, Rand Afrikaans University, Johan nesburg.
- 12 - TAXONOMY
Ecumenicus monohystera (de Man, 1880) Thorne, 1974
Syn. Dorylaimus monohystera de Man, 1880
Eudorylaimus monohystera (de Man, 1880) Andrassy, 1959
(Figure 1; Table 1)
The first description of this species by de Man (1880) was based on female specimens from the Netherlands. It is a cosmopolitan species and has also been reported from South
Africa by Heyns (1961) and by Kruger (1962) who also gave a redescription of this spe cies. Fourteen female specimens corresponding to the redescription by Kruger (1962) were collected in Botswana.
Male and juvenile
Not found.
Locality and habitat
Present specimens, from Chobe National Park: From soil among the roots of grasses under a solitary palm tree (Hyphaene benguellensis) in the north-western part of the Savuti Marsh and from soil among the roots of grasses under mopane trees (Colophospermum mopane) near the Savuti Marsh, collected 27 July 1989.
Specimens
On slides RAU 5152-5156, 5178, 5198, 5199.
- 13 - Eudorylaimus diadematus (Cobb in Thorne & Swanger, 1936) Andrassy, 1959
Syn. Dorylaimus diadematus Thorne & Swanger, 1936
(Figure 2; Table 1)
The first description of Eudorylaimus diadematus was by Cobb in Thorne & Swanger
(1936) from Jamaica, West Indies. Heyns & Lagerwey (1965) reported females from the
Kruger National Park. They stated that E. diadematus is a very common species in south ern Africa and can be easily recognized by a disc-shaped structure between the base of the oesophagus and the cardia, bulging out into the body cavity on the dorsal side. This structure was also mentioned and illustrated by Loof (1964) in specimens from Venezuela.
Ten females and ten juveniles from Botswana are similar to those recorded from the Kruger
National Park by Heyns & Lagerwey (1965) and also by Botha & Heyns (1990b). In some of the present specimens, however, the body length is greater, the total stylet length is slightly less, the stylet aperture as a percentage of the stylet length is greater and the tail is slightly longer. In one specimen from the Chobe National Park, the amphid appears to be divided in two sections (Figure 2F).
Juvenile
(Third stage) (n = 7): L = 0,85-1,04 mm; a = 22,1-26,0; b = 3,0-3,9; c = 17,0-23,2; c'
= 2,2-2,7; odontostyle = 11-15 pm; odontophore = 21-25 pm; total stylet length = 33
37 pm; replacement odontostyle = 13-1 6 pm; tail = 44-57 pm
(Fourth stage) (n = 3): L = 1,13-1,44 mm; a = 27,3-34,3; b = 3,7-4,5; c = 20,9-27,2; c' = 2,0-2,5; odontostyle = 14-15 pm; odontophore = 25-26 pm; total stylet length =
39-41 pm; replacement odontostyle = 16-17 pm; tail = 53-54 pm
General morphology of juveniles similar to adults.
- 14 - Male
Not found.
Locality and habitat
Present specimens from soil among the roots of grasses under mopane trees near the
Savuti Marsh in the Chobe National Park, from soil among the roots of grasses on the northern side of the Kwai River Delta on the northern border of the Moremi Wildlife Reserve and from soil under herbs and palm trees on Boba Island (near Jedibe) in the Okavango
Swamps, collected 27, 28 and 31 July 1989, respectively.
Specimens
On slides RAU 4874, 4875, 4877, 4878,5192 and 5194-5197.
Labronema mauritiense Williams, 1959
(Figure 3; Table 2)
This species was first described by Williams (1959) from sugarcane fields in Mauritius.
He described the female tail as convex-conoid with the terminus blunt and usually slightly, but sometimes distinctly set off. He further reported that the male tail is similar to that of the female, except for the terminus which is less distinctly set off. Thorne (1974) reported one female and one male specimen from Nebraska and South Dakota, U.S.A. According to the illustration of the female tail it is conoid, with a small and distinctly offset terminus.
The male tail is similar in shape, except that it is slightly arcuate ventrad. Botha & Heyns
(1990b) reported four females and one male of this species from the Kruger National Park, with convex-conoid and bluntly rounded tails.
One"male, six females and eight juveniles collected in Botswana, are in full agreement with
- 15 - previous descriptions of this species. The tails of the present specimens are similar to those described by Thorne (1974), except that the digitate part is less distinctly offset in the female. The tail of the male specimen is conoid, slightly arcuate ventrad, with a rounded terminus, but less rounded than that of the Mauritian and Kruger National Park specimens. According to Botha & Heyns (1990b) the amphids of both the Mauritian and
Kruger National Park specimens are stirrup-shaped and divided into two parts. This is also the case in the present specimens (Figure 3E).
Juveniles
(Second stage) (n = 1): L = 0,80 mm; a = 23,5; b = 3,2; c = 23,5; c' = ?; odontostyle
= 14 pm; odontophore = ?; replacement odontostyle = 9 pm; tail = 34 pm
(Third stage) (n = 3): L = 0,77-0,97 mm; a = 24,3-25,7; b = 3,0-3,5; c = 29,6-34,8 (n
= 2); c' = 1,2-1,4 (n = 2); odontostyle = 13-14 pm; odontophore = 14pm (n = 1); total stylet length = 28 pm (n = 1); replacement odontostyle = 15-17 pm; tail = 19-26 pm
(Fourth stage) (n = 4): L = 0,88-1,15 mm; a = 23,4-32,9; b = 3,5-4,1; c = 39,3-47,9; c' = 1,0-1,2; odontostyle = 16-17 pm; odontophore = 21-26 pm (n = 2); total stylet length = 38-43 pm (n = 2); replacement odontostyle = 19-22 pm; tail = 22-29 pm
General morphology of juveniles similar to adults, except for the second stage juvenile and one fourth stage juvenile, where the tail terminus is rounded.
Locality and habitat
Present specimens from soil among the roots of grasses on the northern side of the Kwai
River Delta, at the camping site at the northern entrance gate of the Moremi Wildlife Re serve, and from soil among the roots of a sausage tree (Kigelia africana), standing at the
- 16 - edge of the water on Boba Island in the Okavango Swamps, collected 28, 30 July and 1
August 1989, respectively.
Specimens
On slides RAU 4874, 4879, 4880, 5224, 5268-5270 and 5277.
Discolaimus brevis Siddiqi, 1964
(Figure 4; Table 3)
The original description of Disco/aimus brevis by Siddiqi, 1964 was based on specimens from Alligarh, India. D. brevis closely resembles Disco/aimus manop/anus Heyns, 1963, but according to Botha & Heyns (1990b) it can be distinguished from D. manop/anus by a different lip shape, shorter tail (18-21 pm vs 23 pm), differently shaped amphid (wineglass shaped vs funnel-shaped) and by the absence of a disc-shaped structure between the oesophagus and cardia (see Figure 4A and B of Botha & Heyns 1990b).
Three female specimens from Botswana are in agreement with the description of D. brevis by Siddiqi, 1964, except for a slightly longer tail (19-26 pm vs 18-21 pm) corresponding in this regard also to D. manop/anus. In the present specimens the amphid is however wine glass-shaped and no disc-shaped structure is present between the oesophagus and cardia.
It should be noted that Andrassy (1990) regards D. brevis as a synonym of D. texan us
Cobb, 1913. Although there is remarkable agreement in measurements and general mor phology, the author does not feel that formal synonymy is warrented until the type speci mens have been compared and prefers to call the present specimens D. brevis because of greater correspondence to this species.
Mal~ and juvenile
Not found.
- 17 - Locality and habitat
Present specimens from soil among the roots of grasses under mopane trees near the
Savuti Marsh in the Chobe National Park and from soil among the roots of herbs and palm trees on Boba Island (near Jedibe) in the Okavango Swamps, collected 27 and 31 July
1989, respectively.
Specimens
On slides RAU 5200 and 5224.
Discolaimus major Thorne, 1939
? Syn. Discolaimus paramajor Coomans 1966
(Figure 5; Table 4)
The original description of Discolaimus major by Thorne (1939) was based on specimens collected from various parts in the U.S.A. and from Spain. Heyns (1963) was the first to report this species from southern Africa, from Rustenburg and Nelspruit in the Transvaal and from the Modder River in the Cape Province. Further reports from southern Africa were by van der Vegte & Heyns (1963) and by Botha & Heyns (1990b), both reports from the
Kruger National Park.
Five females and four juveniles, collected in the Chobe National Park, are in agreement with the description of the type population of D. major by Thorne (1939), as well as with other descriptions of this species. The Botswana specimens are, however, slightly shorter than those described by Thorne (1939), Heyns (1963) and Botha & Heyns (1990b) viz. 1,62
1,64 mm vs 1,83-2,24 mm; 1,73-2,40 mm and 1,93-2,20 mm, respectively. Sauer &
Annells (1985) also reported shorter specimens from Australia viz. 1,45-1,88 mm. They were the first to report males of this species and mentioned the presence of large cells in
- 18 - the cardia region and a post rectal (caudal) blind sac in some of the Australian specimens.
The large cells are absent in the Botswana specimens, but a weakly developed post rectal
sac could be seen in most of the specimens. Loof & Coomans (1970) gave a report on the location of the oesophageal gland nuclei in 22 females of D. major. The position of the nuclei in the Botswana specimens (n = 3) agrees fully with that given by Loof & Coomans, viz. oesophagus widens at 41-43 %; DO lies 26-23 pm behind the latter level; distance
DO-ON = 13-16 pm; DO = 48-52 %; DN = 53-56 %; 510 = 83 %; 51N1 = 83 % (n =
1); S1N2 = 84% (n = 1); ~O = 92-93 %; ~1 = 89-90 % (n = 2); ~2 = 89 % (n = 2).
Male
Not found.
Juvenile
(?Second stage) (n = 1): L = 1,06 mm; a = 36,6; b = 3,8; c = 37,9; c' = 1,4; odon tostyle = 14 pm; odontophore = 23 pm; total stylet length = 37 pm; replacement odon tostyle = 10 pm; tail = 30 pm
(?Third stage) (n = 3): L = 1,30-1,40 mm; a = 37,1-37,8; b = 3,8-4,0; c = 43,3
50,3; c' = 1,3-1,4; odontostyle = 15-17 pm; odontophore = 26-29 pm (n = 2); total stylet length = 43-45 pm (n = 2); replacement odontostyle = 18-20 pm; tail = 27-28 pm
General morphology similar to adults, except no post rectal sac could be seen.
Remarks
D. major closely resembles Discolaimus paramajor Coomans, 1966 regarding body length andall other morphometrical data as well as morphological features (see Table 4). Accord ing to Coomans (1966), D. paramajor can be distinguished from D. major by the presence
- 19 - of males, prerectum with caudal blind sac and by three pairs of caudal pores in the female tail (two in D. major). Sauer & Annells (1985) however reported specimens with two or three pairs of caudal pores. In the Botswana specimens only two pairs are conspicuous, except in one specimen where three pairs could be seen.
Considering the wide distribution of D. major, the fact that males have now been found by
Sauer & Annells as well as the presence of a post rectal sac and three caudal pores, it is suspected that D. paramajor may be a synonym of D. major. However, the author refrains from formally proposing such synonymy, since the type material of these two species has not been examined.
Locality and habitat
Present specimens fom soil among the roots of grasses under an Acacia tree at Serondella, close to the Chobe River and from soil among the roots of grasses under mopane trees near the Savuti Marsh, both in the Chobe National Park, collected 26 and 27 July 1989, respectively.
Specimens
On slides RAU 5142, 5144, 5149, 5150 and 5197-5199.
Discolaimium simplex Siddiqi, 1965
A single female from Botswana is in full agreement with the original description of Disco laimium simplex by Siddiqi 1965.
Measurements
Female (n = 1): L = 1,57 mm; a = 35,7; b = 3,65; c = 46,2; c' = 1,4; V = 43%; odontostyle = 20 pm; odontophore = 33 pm; total stylet length = 53 pm; tail = 34 Jim
- 20- Brief description
Lip region 23 pm wide. Amphid stirrup-shaped, its aperture 13 pm wide or 57% of lip region width. Guiding ring 11 pm from anterior end. Oesophagus 430 pm long; basal bulb 270 pm long. Oesophageal gland nuclei indistinct. Nerve ring 112 pm from anterior end. Lateral field 20 % of corresponding body width; fairly large hypodermal glands present. Reproductive system as in original description. Rectum 75 pm long. Prerectum indistinct. Tail as in original description; caudal papillae inconspicuous.
Remark
Andrassy (1990) suggested that D. simplex may be a synonym of Discolaimium mucuruba num (Loof, 1964) Andrassy, 1990. For the same reasons as given under D. brevis the author prefers to regard the present specimens as D. simplex.
Male and juvenile
Not found.
Locality and habitat
Present specimens from soil among the roots of herbs and palm trees, Boba Island (near
Jedibe) in the Okavango Swamps collected 31 July 1989.
Specimen
On slide RAU 5215.
Discolaimoides bulbiferus (Cobb, 1906) Heyns, 1963
(Table 3)
The original description of Discolaimoides bulbiferus was by Cobb (1906) from Hawaii.
- 21 - Thorne (1939) gave a redescription from topotypes collected from a pineapple field in
Hawaii. Heyns (1963) was the first to report this species from southern Africa. Loof
(1964) described eleven females as well as the first male of this species from Venezuela.
Das, Khan & Loof (1969) studied the topotypes and gave some additional data to that of
Thorne (1939). According to these authors the dorsal gland nucleus lies far behind the beginning of the widening of the oesophagus (18 Jim in the topotype; 22-29 Jim in the
Venezuelan specimens).
Eight female and two juvenile specimens from Botswana are in complete agreement with the descriptions by Heyns (1963), Loof (1964) and by Das et al. (1969). The distance of the dorsal gland nucleus from the beginning of the widening of the oesophagus is, how ever, somewhat greater, viz. 40 Jim or at 60 % of oesophageal length (n = 2).
Juvenile
(Fourth stage) (n = 2): L = 1,26 & 1,34 mm, a = 43,4 & 46,2; b = 4,7 & 5,2; c =
31,5 & 29,8; c' = 2,2 & 2,8; odontostyle = 11 & 10 Jim; odontophore = 19 & 17 pm; total stylet length = 30 & 27 utn; replacement odontostyle = 13 & 10 Jim; tail = 40 &
49 pm
General morphology similar to adults.
Male
Not found.
Locality and habitat
Present specmens from soil among the roots of grasses under an Acacia tree at Serondella close to the Chobe River and from soil among the roots of grasses under mopane trees near the Savuti Marsh Chobe National Park; from soil among the roots of grasses under
- 22- large mopane trees at the camping site near the northern entrance gate of the Moremi
Wildlife Reserve and among the roots of herbs and palm trees, Boba Island (near Jedibe) in the Okavango Swamps, collected 26,27, 30 and 31 July 1989, respectively.
Specimens
On slides RAU 5130, 5142, 5149, 5150, 5202 and 5211.
Aporcelaimellus adriaani Botha & Heyns, 1990
(Figure 6; Table 5)
Botha & Heyns (1990a) described Aporcelaimellus adriaani from seven females collected at the Tsokwane picnic area, Kruger National Park.
Two females, three juveniles and for the first time three male specimens to be found of A. adriaani were collected in the Okavango Swamps. These are in agreement with the type population of this species. The body length, as well as a and c-ratios of the present specimens are somewhat greater (1,63-1,88 mm vs 1,23-1,49 mm; 42,3-45,9 vs 23-30 and 63,9-74,0 vs 42-58, respectively). The rectum (discernible in only one of the
Botswana specimens) is also longer (38 Jim vs 26-30 pm).
Description
Female
General description for female as in original description. Lateral body pores, however, dis cernible, though small, arranged in a single row. Dorsal and ventral pores obscure. Odon tophore not thickened at its base. No disc could be seen between oesophagus and cardia.
Anterior and posterior reproductive branches 254 and 264 Jim; anterior and posterior ovaries 117 and 82 Jim long, respectively (n = 1). Vagina occupying 32 % of correspond ing body diameter (n = 1). Sperm cells present in both uteri of one specimen. No eggs
- 23 - present. Tail conoid, bluntly rounded with two pairs of caudal papillae.
Male
Description as for female with the following differences. Heat-relaxed body posture slightly to more strongly curved ventrad, especially in posterior region. Reproductive system diorchic, testes opposed and outstretched with a common sperrnoduct, no muscular ejacu latory duct present. Spermoduct merging with alimentary canal 40-42 pm anterior to cloacal opening. Anterior and posterior testes 142 pm and 115 pm long, respectively (n =
1). Sperm cells spindle-shaped, 7-9 pm long. Spicules relatively short, arcuate. Each spiculum with a distinctly wrinkled area in the spicular sheath in one specimen (Figure 6C).
Lateral guiding pieces slender, distally bifurcate. One pair of adanaI supplements situated close to cloacal opening. Ventromedian supplements five in number, mammiform. First two supplements contiguous, others non-contiguous (Figure 6F and H). Tail similar to that of female, slightly curved ventrad in one specimen with two pairs of caudal papillae.
Juvenile
(Fourth stage) (n = 3): L = 0,86-1,11 mm; a = 23,8-37; b = 2,9-3,9; c = 31,9-46,3; c' = 1,3-1,4; odontostyle = 9-12 pm; replacement odontostyle = 9-13 pm; tail = 24
27 pm
General morphology similar to adults. Odontophore obscure in all specimens.
Remark
One male specimen from the Chobe National Park (from Serondella), is morphologically similar to A. adriaani but has a wider lip and neck region, smaller c-ratio, shorter testes and more ventromedian supplements.
- 24- Measurements
L = 1,34 mm; a = 41,9; b = 3,9; c = 53,6; c' = 1,8; lip region width = 20 pm; odontostyle = 13 pm; odontophore = 24 pm; total stylet length = 37 pm; stylet aperture as % of odontostyle = 46; guiding ring from anterior end = 8 pm; lateral chord as % of body width = 19; prerectum = 112 pm; tail = 25 pm; anterior testis = 95 pm; posterior testis = 75 pm; spiculum = 37 pm; lateral guiding piece = 9 pm; number of ventrome dian supplements = 10
Locality and habitat
Chobe National Park: Juveniles (n = 2): from soil among the roots of grasses next to an
Acacia tree at the Lamont ruins, and from soil among the roots of grasses under Mopane trees near the Savuti Marsh. Adults and one juvenile: from brackish soil among the roots of grasses on Boba Island in the Okavango Swamps, collected 26, 27 and 28 July 1989, respectively.
Specimens
On slides RAU 5150, 5191-5192, 5236, 5238-5241.
Aporcelaimellus micropunctatus Botha & Heyns, 1990
(Figure 7; Table 6)
Botha & Heyns (1990a) described Aporcelaimellus micropunctatus from the Kruger Natio nal Park, collected among the roots of unidentified grasses.
Twelve females, three juveniles and the first three male specimens to be found of A. micropunctatus were collected from the Okavango Swamps and Chobe National Park.
These are in almost complete agreement with the type population of A. micropunctatus.
- 25 - Description
Female
Heat-relaxed body posture slightly to very strongly curved ventrad in the shape of a letter
C to almost a complete circle in one specimen. Cuticle as in original description, 4-7 pm thick on the neck, 5-8 pm at mid-body, 5-7 pm around the tail tip. Body pores distinct.
Lateral pores 15-17 to base of oesophagus, 11-18 between oesophagus and vulva and 19
28 between vulva and anus, not diverging into two rows as mentioned in the original description. (Examination of the holotype, however, revealed only one row). Ventral pores
11-16 to base of oesophagus, 4-11 between oesophagus and vulva and 8-12 between vulva and anus. Dorsal pores 7-8, limited to anterior oesophageal region.
Lip region, amphid and stylet similar to that in original description. No rudimentary excre tory pore seen in Botswana specimens. Oesophago-intestinal disc rather distinct in all specimens, except in one female from the Chobe National Park. Hemizonid opposite nerve ring, 150-174 pm from anterior end. Tail conoid, bluntly rounded; two pairs of caudal papil lae present.
Anterior and posterior reproductive branches 165-280 pm and 132-250 pm long, respect ively. Anterior and posterior ovaries 67-250 pm and 78-133 pm long, respectively.
Sphincter muscle distinct. Vagina strongly muscular, occupying 27-32 % of the corre sponding body width. Vulva lips sclerotized. No eggs or sperm cells observed.
Male
Similar to female, except heat-relaxed body posture slightly curved ventrad, with posterior region more curved ventrad. Cuticle 4-5 pm on neck, 7-9 pm at mid-body, 8-15 pm around the tail tip; punctations conspicuous towards tail end. Lateral pores 22- 25 to base of oesophagus and 95-100 between oesophagus and anus, small, close together,
- 26- diverging just before anteriormost ventromedian supplement. Ventral pores 11-15 to base of oesophagus, 38-39 between oesophagus and anteriormost ventromedian supplement.
Dorsal pores eight (n = 1), limited to anterior oesophageal region.
Reproductive system diorchic, testes opposed and outstretched with common spermoduct.
No muscular ejaculatory duct present. Spermoduct merging with alimentary canal 63 pm anterior to cloacal opening. Anterior and posterior testes 380-490 pm long, respectively.
Sperm cells distinct, ovoid, about 6 pm long. Spicules rather slender. Lateral guiding pieces slender with bifurcated termini. In one specimen two and in another, three ejacula tory glands could be seen, inconspicuous in third specimen. One pair of adana I supple ments situated close to cloacal opening, mammiform and non-contiguous. Rectal glands distinct in two specimens, their ducts inconspicuous. Tail shape similar to that of female, with two pairs of caudal papillae.
Juvenile
(Fourth stage) (n = 2): L = 1,91 & 2,06 mm; a = 25,8 & 31,7; b = 3,7; c = 63,7 &
66,5; c' = 0,7 & 0,9; odontostyle = 20 & 21 pm; odontophore = 35 pm; total stylet length = 55 & 56 uttv; replacement odontostyle = 23 & 24 pm; tail = 30 & 31 pm
(Third stage) (n = 1): L = 1,55 mm; a = 22,1; b = 3,7; c = 53,4; c' = 0,9; odontostyle
= 17 pm; odontophore = 25 pm; total stylet length = 43 pm; replacement odontostyle =
20 pm; tail = 29 pm
Locality and habitat
Present specimens from Chobe National Park: from soil among the roots of grasses under an Acacia tree at Serondella, close to the Chobe River, and from soil among the roots grasses under a solitary palm tree in the north-western part of the Savuti Marsh. Three samples taken on Boba Island, near Jedibe, viz. from soil among the roots of herbs and
- 27- palm trees; from brackish soil among the roots of grasses, and among the roots of a sausage tree (Kigelia africana), standing at the edge of the water, collected 26, 30 July and 1 August 1989, respectively.
Specimens
On slides RAU 5114, 5147, 5125,5174,5175,5220-5222,5240 and 5280.
Aporcelaimellus papiJlatus (Bastian, 1865) Baqri & Khera, 1975
Syn. Dorylaimus papiJlatus Bastian, 1865
(Figure 8; Table 5)
The first description of this species was by Bastian (1865) from female specimens collec ted at Broadmoor, Berks, England. Bastian gave a very short description with an illustra tion of only the neck region and tail. Thorne & Swanger (1936) described both females and males from various localities in Europe and Woods Hole, Massachusetts, U.S.A.
Two female and two male specimens from the Chobe National Park, are for the first time recorded from southern Africa. These specimens are very similar to those described by
Thorne & Swanger (1936). They differ, however, in the somewhat shorter odontostyle, longer spicules, longer lateral guiding pieces and slightly less ventromedian supplements
(see Table 5).
Brief description
Female
Heat-relaxed body posture curved ventrad in an open letter C or in an incomplete figure six.
Cuticle 3 and 4 pm on neck, 4 pm at mid-body, 10 pm around tail tip. No punctations seen. Dorsal and ventral body pores indistinct. Lateral pores not very prominent, a single row and irregularly spaced, 12-13 to base of oesophagus, 19-1 6 between oesophagus and
- 28 - vulva, 25-37 between vulva and anus.
Lip region offset. Lips angular with distinct papillae. Amphid funnel-shaped, in lateral
view appearing to be transversely divided into two sections. Guiding ring single, unsclero
tized. A disc-like structure present between oesophagus and intestine. Intestine with
four cells in circumference. Tail convex-conoid, bluntly rounded, with two pairs of caudal
papillae.
Reproductive system didelphic-amphidelphic. Vulva a transverse slit, lips without scleroti
zation. Distinct sphincter muscle between pars dilatata uteri and pars dilatata oviductus.
Sperm cells present in uteri.
Male
Similar to female, except heat-relaxed body posture more strongly curved ventrad. Puncta
tions could be seen on cuticle in one specimen. Lateral pores 14 to base of oesophagus,
52-64 between oesophagus and anus, diverging just anterior to level of anteriormost ven
tromedian supplement in one specimen, at level of germinal zone of posterior testis in the
other specimen. Reproductive system diorchic, testes opposed, anterior and posterior
testes 328-330 pm, and 304-324 pm long, respectively. Common spermoduct present,
merging with alimentary canal 150 pm (n = 1) anterior to cloacal opening. No muscular
ejaculatory duct present. Sperm cells elongate-ovoid, about 7 pm long. Spicules slender.
Lateral guiding pieces slender, termini not bifurcate. One pair of adanal supplements situa ted close to cloacal opening. Ventromedian supplements mammiform, non-contiguous,
widely spaced, five in number. Tail shape as in female, with two pairs of caudal papillae.
Remarks
A. papillatus and A. obtusicaudatus (Bastian, 1865) Altherr, 1968 are two closely related
species. They were both described from England by Bastian (1865) in the same publica-
- 29 - tion. The main differences between these species were size and also tail shape. Thorne &
Swanger (1936) maintained the two species, apparently on the basis of tail shape. There
were numerous reports of both species in the literature, but apparently also much uncer
tainty about the identity of both. Baqri & Coomans (1973) found great variation in popula
tions from the Virunga National Park, Zaire, also in size and tail shape, which may indicate
synonymy of the two species. Until this situation is resolved by a thorough study, the
author regards the present specimens as A. papillatus, mainly because of large size and tail
shape.
Locality and habitat
Present specimens from soil among the roots of grasses under an Acacia tree at Serondel
la, close to the Chobe River in the Chobe National Park, collected 26 July 1989.
Specimens
On slides RAU 4839 and 4842.
AporcelaimeJlus parapapilJatus Botha & Heyns, 1990
(Figure 9; Table 7)
Botha & Heyns (1990a) based their description of this species on three female and three
male specimens collected among the roots of unidentified grasses near the look-out at
Engelhard Dam in the Kruger National Park.
Three female, three male and two juvenile specimens from the Chobe National Park and
Okavango Swamps, are in agreement with the type population of A. parapapillatus. The
Botswana specimens, however, are somewhat longer, have a slightly greater total stylet length, slightly longer tails and fewer ventromedian supplements.
- 30- Brief description
Female
Heat-relaxed body posture varying from only slightly curved ventrad to more strongly curved ventrad in almost a complete circle or incomplete figure six. Cuticle 4-5 pm thick on neck, 6-9 pm at mid-body, 7-12 pm around the tail tip. Lateral pores distinct, a single row, irregularly spaced, diverging just before anus in the Okavango specimens, not diver ging in the Chobe National Park specimen; 23-34 to base of oesophagus, 36-39 between oesophagus and vulva, 51-59 between vulva and anus. Ventral pores 13-19 to base of oesophagus (n = 2), 19-20 between oesophagus and vulva (n = 2), 25-27 between vulva and anus. Dorsal pores eight, limited to anterior oesophageal region (n = 1).
Lip region offset. Amphid funnel-shaped, not divided into two sections. Odontostyle and odontophore as in original description. Guiding ring single, unsclerotized. Excretory pore not seen. Hemizonid distinct in one specimen, just anterior to nerve ring. Oesophago intestinal disc absent. Intestine six cells in circumference. Tail conoid, bluntly rounded, somewhat shorter in one specimen. Two pairs of caudal papillae present in two speci mens, three pairs in third specimen.
Reproductive system as in original description. Sperm cells present in uteri as well as in oviducts in one specimen.
Male
Similar to female. Heat-relaxed body posture only slightly curved ventrad, posterior part not as strongly curved as in the type specimens. Lateral hypodermal glands distinct; lateral pores irregularly spaced, a single row diverging into two rows just anterior to level of ante riormost ventromedian supplement, 24 to base of oesophagus, 78 between oesophagus and anteriormost ventomedian supplement and 19 from there to anus.
- 31 - Reproductive system as in original description; anterior and posterior testes 240-332 pm and 200-321 pm long, respectively. Common spermoduct present, merging with alimen tary canal 63 pm (n = 1) anterior to cloacal opening. No muscular ejaculatory duct pre sent. Sperm cells ovoid, about 4 pm long. Spicules long and slender; spicular sheath with distinctly wrinkled area in one specimen. Lateral guiding pieces slender, termini not bifur cate. Adanal pair of supplements situated close to cloacal opening. Ventromedian sup plements mammiform, non-contiguous, but close together, 10 and 11 in number. Tail shape as in female, with three pairs of caudal papillae.
Juvenile
(Third stage) (n = 2): L = 1,15 & 1,33 mm; a = 24,5 & 23,8; b = 3,5 & 3,3; c = 33,8
& 42,9; c' = 1,3 & 1,1 ; odontostyle = 14 & 15 pm; odontophore = 24 & 29 pm; total stylet length = 38 & 44 pm, replacement odontostyle = 17 & 19 uttv; tail = 34 & 31 pm
General morphology of juveniles similar to adults. Disc-like structure between oesophagus and intestine present in one specimen.
Remarks
A. parapapillatus is very close to A. papillatus (Bastian 1865) Baqri & Khan, 1975. Accord ing to Botha & Heyns (1990a), it can be distinguished from A. parapapillatus by the more posterior vulva position and greater number of ventromedian suppplements. With the discovery of the new populations of A. papillatus from Botswana, further differences became evident. A. parapapillatus differs from A. papillatus also by the wider lip region
(18-23 pm vs 15-17 pm); greater lip region height (6-8 pm vs 4-5 pm); longer odonto phore (26,5-38 pm vs 26-27 pm); longer tail (27-48 pm vs 20-29 pm), longer rectum (46
62 pm vs 36-40 pm ); longer spicules (73-89 pm vs 52-61 pm) and somewhat longer and differently shaped sperm cells (ovoid vs elongate-ovoid).
- 32 - Locality and habitat
Present specimens from soil among the roots of grasses under an Acacia tree at Serondel la, close to the Chobe River, Chobe National Park, and from soil under herbs and palm trees on Boba Island (near Jedibe) in the Okavango Swamps, collected 26 and 31 July 1989, respectively.
Specimens
On slides RAU 5114,5148, 5220, 5222, 5223 and 5225.
Mesodorylaimus usitatoides spec. nov.
(Figure 10; Table 8)
Description
Female (n = 8)
Body of medium length and relatively slender. Heat-relaxed body posture almost straight or only slightly curved ventrad. Cuticle with minute radial striations. Lateral chord varying from about one sixth to one third the corresponding body width. Body pores indistinct.
Lip region offset by a constriction. Lips partly amalgamated. Labial papillae rather protrud ing, resulting in the lips having an angular appearance; number and arrangement of papillae typically dorylaimoid. Amphid aperture conspicuous in only one specimen, a wide slit, slightly less than one half the lip region width, situated at level of constriction between lip region and adjoining body. Fovea funnel-shaped. Amphideal fusus with sensilla not vis ible. Length of odontostyle about equal to lip region width. Stylet aperture about one third and one half the odontostyle length. Guiding ring single, sclerotized. Odontophore 1,6 to
1,7 times the odontostyle length. Nerve ring distinct, encircling anterior slender part of oesophagus about midway; numerous nerve cells visible, mostly behind nerve ring.
- 33 - Hemizonid conspicuous in all but two specimens, situated at level of nerve ring. Hemizo nion not seen. Anterior slender part of oesophagus less muscular than basal expanded part, broadened around posterior half of odontophore. Oesophagus widening at 56 (51-61)
% from anterior end. Oesophageal gland nuclei and their outlets obscure, except dorsal gland nucleus and outlet conspicuous in one specimen, situated at 67 % and 64 % of oesophagus length, respectively. Cardia elongate-conoid, 13 (10-16) pm long and 9 (7
10) pm wide, anterior third appearing more strongly muscular, giving the impression of a disc-like structure in some specimens. Intestinal wall containing numerous yellow granules, individual cells obscure. Prerectum length 2,8 (2,4-3,2) ( n = 5) times the anal body diameter. Rectum 1,6 (1,3-1,8) (n = 6) anal body widths long. No rectal glands seen.
Tail elongate-conoid, slightly curved dorsad at about its middle. Tail tip rounded. Hyaline part 19 (17-20) (n = 7) long, or cytoplasmic core occupying 77 (73-83) % (n = 7) of tail length. Caudal papillae not always conspicuous, two or three pairs.
Reproductive system didelphic-amphidelphic, posterior branch slightly better developed; the anterior and posterior branches 184 (168-204) pm and 196 (177-230) pm long or occupy ing 14,9 (13,4-15,8) % and 15,9 (14,1-19,6) % of total body length, respectively. Ovar ies reflexed, anterior and posterior ovaries 89 (60-152) pm and 105 (76-107) pm long, respectively. Oviduct and pars dilatata oviductus well developed. Sphincter muscle be tween pars dilatata oviductus and uterus present, however, not very evident. No distinct pars dilatata uteri present. Uteri always broadened and filled with numerous sperm cells, apparently serving as a spermatheca. Sperm cells also present in pars dilatata oviductus in one specimen. Vagina occupying 44 (37-51) % of the corresponding body diameter, thick walled. Vulva a transverse slit with weakly sclerotized lips. No uterine eggs observed.
Male (n = 5)
Description as for female with the following differences. Ventral curvature of body more pronounced in tail region. Reproductive system diorchic, testes opposed and outstretched,
- 34- with common sperrnoduct. No muscular ejaculatory duct present. Spermoduct merging with alimentary canal 35 (34-37) pm (n = 4) anterior to cloacal opening. Sperm cells elongate-ovoid to spindle-shaped, 6-9 pm long. Three pairs of ejaculatory glands promi nent anterior to supplements, the course of their ducts could not be followed. Spicules arcuate, well developed. Lateral guiding pieces almost V-shaped, short and stout. Sup plements mammiform, somewhat flattened, consisting of an adanal pair and a row of 7 to
10 contiguous ventromedian ones. No rectal glands observed. Tail short, conoid, slightly curved ventrad, the terminus bluntly rounded. Two or three pairs of caudal papillae pre sent.
Juvenile
(Third stage) (n = 2): L = 0,71 & 0,72 mm; a = 35,5 & 34,3; b = 4,7 & 3,8; c = 10,5
& 10,9; c' = 6,0 & 5,5; odontostyle = 9 pm; odontophore = 14 pm (n = 1); total stylet length = 23 pm (n = 1); replacement odontostyle = 10 & 9 pm; tail = 67 & 66 pm; cytoplasimic core as % of tail length = 19 & 12
(Fourth stage) (n = 10): L = 0,89-1,09 mm; a = 32,9-40,8; b = 3,8-4,5; c = 11,5
16,9; c' = 3,9-6,0; odontostyle = 9-11 pm; odontophore = 15-19 pm (n = 6); total stylet length = 25-29 pm (n = 6); replacement odontostyle = 11-13 pm; tail = 62-100 pm; cytoplasmic core as % of tail length = 11-23
General morphology similar to adults, except sexual dimorphism not present.
Type locality and habitat
Present specimens from brackish soil among the roots of grasses, Soba Island in the
Okavango Swamps, collected 1 August 1989.
- 35- Type specimens
Holotype: Female (second specimen left) on slide RAU 5239. Paratypes: Seven females on slides RAU 5232, 5234, 5235 and 5239 and five males on slides RAU 5233 and 5239.
Diagnosis
Mesodorylaimus usitatoides can be recognised by the following characters: medium sized body; offset lip region; protruding labial papillae; transverse vulva; elongate-conoid female tail; short spicules and rather short, stout and V-shaped lateral guiding pieces.
Relationships
M. usitatoides is very close to Mesodorylaimus usitatus Basson & Heyns, 1974, but has a definite offset lip region compared to the almost confluent lip region of M. usitatus, differ ently shaped female tail, contiguous supplements (non-contiguous in M. usitatus) and longer sperm cells (M. usitatoides = 6-9 pm; M. usitatus = 5,4-6,1 pm).
It is also similar to Mesodorylaimus musae Geraert, 1962 differing in the greater c-ratio
(female: 13,3-18,4 vs 4,8-7,65; male: 72,5-81,4 vs 35,4-58,6; shorter female tail (70
103 pm vs 161 pm); more offset lip region and slightly longer males (1,14-1,32 mm vs
0,7-1,1 rnm).
M. usitatoides also resembles Mesodorylaimus bastiani (Butschli, 1873) Andrassy, 1959.
It can be distinguished from the topotypes described by Loof (1969), by its slightly short er body (female: 1,17-1,29 mm vs 1,60-1,64 mm; male: 1,14-1,32 mm vs 1,47-1,73 mrn): more anteriorly situated vulva (47-53 % vs 53-60 % ); shorter female tail (14-18 pm vs, 24,1 pm); shorter spicules (31-36 pm vs 43-44 pm); more offset lip region and more protruding labial papillae ("hardly protruding" in M. bestisnh.
The new species can also be compared with Mesodorylaimus parasubulatus (Meyl, 1954)
- 36 - Andrassy, 1959, but has a somewhat greater body length and longer tail in the female
(1,14-1,29 mm and 70-103 pm vs 0,9 mm and 54 pm); slightly longer odontostyle (11- 14 vs 8,8 pm) and differently shaped lateral guiding pieces (narrower and more cylindrical in
M. parasubulatus).
(7) Prodorylaimus/Laimydofus species
(Figure 11)
A single female from the Okavango Swamps, has characteristics of Prodorylaimus as well as Laimydorus. These genera can only be distinguished on the basis of the tail shape of the male specimens (long and filiform in Prodorylaimus, short and rounded in Laimydorus).
According to Loof (1985) all monosexual species (not belonging to the related genus
Mesodorylaimus) should be included in Prodorylaimus. Since sperm cells are present in the uteri of the present specimen, it obviously does not belong to a monosexual species, and could thus be either Prodorylaimus or Laimydorus. However, since the male was not found, it cannot be determined to which of the two genera it belongs.
Measurements
Female: (n = 1): L = 2,32 mm; a = 43,8; b = 5,0; c = 5,3; c' = 12,3; V = 44,5 %; lip region width = 16 pm; lip region height = 6,5 pm; odontostyle length = 25 pm; odontostyle width = 3 pm; odontophore length = 29 pm; total stylet length = 54 pm; tail length = 437 pm
Description
Heat-relaxed body posture curved ventrad in a widely open letter C. Cuticle with minute striations; 3pm wide on neck, 5 pm wide at midbody, 5 pm wide at level of anus. Lateral chord 9 % of the corresponding body width. Lateral body pores distinct, distributed over entire body length, seven in number up to oesophagus, eight between oesophagus and
- 37- vulva, 10 between vulva and anus. Ventral body pores conspicuous in neck region, sometimes visible over rest of body. Dorsal pores indistinct.
Lip region apparently slightly offset. Lips partly amalgamated; labial papillae rather pro truding, resulting in an angular lip region appearance. Amphid apertures situated at level of constriction between lip region and adjoining body. Length of odontostyle about one and a half times lip region width. Stylet aperture 36 % of odontostyle length. Odontophore almost equal in length to odontostyle. Guiding ring double, 20 pm from anterior end.
Nerve ring encircling oesophagus at 154 pm from anterior end; numerous nerve cells vis ible. Hemizonid not seen. Oesophagus broadened around posterior half of odontophore, followed by a constriction, then widening again to form anterior slender part. Basal bulb occupying 44 % of total oesophagus length. Oesophageal gland nuclei and outlets dis tinct; positions as percentage of oesophagus length are the following: DO = 57 %; DN
= 60,2 %; St01& S1N1 = 74,6 %; S102 & S1N2 = 80,4 %; ~1 = 89,8 %; ~1 = 87,8
%; S202 = 89,8 %; S2N2 = 88,2 %. Cardia elongate-conoid, 33 pm long, 9 pm wide.
Intestine four cells in circumference. Prerectum 98 pm long or 2,8 times the anal body diameter. Rectum 42 pm, or 1,2 anal body widths long. Tail long, ending in a recurved and arcuate terminus (Figure 11 E). Cytoplasmic core 381 pm long or occupying 87 % of tail length; hyaline part 56 pm. Two pairs of caudal papillae present.
Reproductive system didelphic-amphidelphic. Anterior and posterior branches 275 pm and
292 pm long, respectively. Ovaries reflexed, well developed; anterior and posterior ovaries
211 pm and 225 pm long, respectively. Oviduct and pars dilatata oviductus distinct.
Sphincter muscle between pars ditetete oviductus and uterus weakly developed. No pars dilatata uteri present. Uteri filled with numerous sperm cells, latter also present in posterior pars dilatata oviductus. Vulva appearing to be longitudinal. No uterine eggs present.
- 38- Male and juvenile
Not found.
Locality and habitat
Present specimen from soil among the roots of a sausage tree (Kigelia africana) standing at the edge of the water on Boba Island in the Okavango Swamps, collected 1 August
1989.
Specimen
On slide RAU 5267.
Diagnosis
Prodorylaimus/Laimydorus sp. has a medium body length; rather long tail with the tail terminus recurved and arcuate; double guiding ring; odontophore almost equal in length to
odontostyle and longitudinal and pre-equatorial vulva.
Relationships
Prodorylaimus/Laimydorus sp. resembles the following Prodorylaimus species:
P. paralongicaudatus (Micoletzky, 1925) Andrassy, 1959. Prodorylaimus/Laimydorus sp. comes very close to the Kenyan specimens (Nairobi, Thika and Mugaga) found by Loof
(1985), but differs in the somewhat longer tail (437 pm vs 175-266 pm), greater cyto
plasmic core percentage (87 % vs 60-69 %) and differently shaped sperm cells (ovoid vs more elongate-ovoid).
P. picardi (Altherr, 1963) Loof, 1985. Prodorylaimus/Laimydorus sp, is longer (2,32 mm vs
1,46 rnrn), has a greater a-ratio (43,8 vs 35), somewhat greater band c-ratios (5,0 vs 4,3 and 5,3 vs 4,4); longer tail (437 pm vs 330 pm) and has sperm cells in the uteri vs no sperm cells in P. picerdi.
- 39 - P. vixamictus (Andrassy, 1962) Loof , 1985. Prodorylaimus/Laimydorus sp. has a greater a-ratio (43,8 vs 32,2-34,8), shorter odontostyle (25 pm vs 30-31 pm) and smaller lip region width (16 pm vs 21 pm).
Prodorylaimus/Laimydorus sp. also resembles the following Laimydorus species:
L. cryptosperma (Loof, 1969) Loof, 1985. Prodorylaimus/Laimydorus sp. has a greater a ratio (43,8 vs 28-38), smaller c-ratio (5,3 vs 10-12), longer tail (437 pm vs 60-70 pm), shorter odontophore (29 pm vs 33-35 pm), greater c'-ratio (12,3 vs 6-7) and differently shaped sperm cells in the uteri (ovoid vs elongate-ovoid).
L. parafecundus (De Coninck, 1935) Loof & Coomans, 1986. Prodorylaimus/Laimydorus sp. is shorter (2,32 mm vs 2,77-2,93 mm), has a greater a-ratio (43,8 vs 36-39), shorter odontostyle (25 mm vs 41-46 pm) and somewhat shorter tail (437 pm vs 523-637 pm).
ACKNOWLEDGEMENTS
Thanks are due to the Foundation for Research Development of the CSIR for financial support, and Dr. P.A.A. Loof for valuable comments on the manuscript.
REFERENCES
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BASTIAN, H.C. 1865. Monograph on the Anguillulidae, or free nematoids, marine, land
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BOTHA, ANNELIZE & HEYNS, J. 1990a. Aporcelaimidae (Nematoda: Dorylaimida) from
the Kruger National Park. Koedoe 33: 27-46.
BOTHA, ANNELIZE & HEYNS, J. 1990b. DoryJaimoidea (Nematoda) from the Kruger Natio
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COBB, N.A. 1906. Free living nematodes inhabiting the soil about the roots of cane, and
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Ass. Exp. Stn. 5: 163-195.
COOMANS, A. 1966. Some nematodes from Congo. Rev. Zool. Bot. afro 74: 287-312.
DAS, V.M., KHAN, E. & LOaF, P.A.A. 1969. Revision of the genus Discolaimoides
Heyns, 1963 with description of two new species reminiscent of this genus.
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DE MAN, J.G. 1880. Die Einheimischen, frei in der reinen Erde und im sussen Wasser
lebende Nematoden. Tijdschr. Nederl. Dierk. Vereen. 5: 1-104.
HEYNS, J. 1961. Taxonomic studies on Nematodes from South Africa. Ph.D thesis, Uni
versity of Wisconsin. 92 pp.
- 41 - HEYNS, J. 1963. A report on South African nematodes of the genera Labronema Thorne,
Discolaimus Cobb, Discolaimoides n. gen., and Discolaimium Thorne (Nemata:
Dorylaimoidea). Proc. Helm. Soc. Wash. 30: 1-6.
HEYNS, J. & LAGERWEY, GERDA 1965. Nematodes of the superfamily Dorylaimoidea
collected in the northern part of the Kruger National Park. Koedoe 8: 129-135.
KRUGER, S.P. 1962. Nematodes of the suborders: Alaimina and Dorylaimina (order: En
oplida) from South Africa. M.Sc. thesis, University of Pretoria. 54 pp.
LOOF, P.A.A. 1964. Free-living and plant parasitic nematodes from Venezuela. Nemato
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LOOF, P.A.A. 1969. Taxonomy of some species of the genus Mesodorylaimus Andrassy,
1959 (Dorylaimoidea). Nematologica 15: 253-274.
LOOF, P.A.A. 1985. Taxonomic studies on the genus Prodorylaimus Andrassy, 1959
(Nematoda: Dorylaimina). Revue Nematol. 8: 193-213.
LOOF, P.A.A. & COOMANS,A. 1970. On the development and location of the oesophageal
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161.
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SAUER, M.R. & ANNELLS, C.M. 1985. Species of Discolaimus (Nematoda: Dorylaimoi
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- 42- SIDDIQI, M.R. 1964. Studies on Discolaimus spp. (Nematoda: Dorylaimidae) from India.
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SIDDIQI, M.R. 1965. Five new species of soil nematodes in the genera Dorylaimoides
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THORNE, G. & SWANGER, HELEN, HEINLY 1936. A monograph of the nematode genera
Dorylaimus Dujardin, Aporeelaimus n.g., Dorylaimoides n.g. and Pungentus n.g.
Capita Zool. 6: 1-223.
VAN DER VEGTE, EA. & HEYNS, J. 1963. A report on nematodes found in soil and root
samples from the Kruger National Park. Koedoe 6: 134-136.
WILLIAMS, J.R. 1959. Studies on the nematode soil fauna of sugarcane fields in Mauri
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(Published in the South African Journal ofZoology 27)
- 43- TABLE 1: Morphometric data of ECUlllenicus monohystera (de Man. 1880) Thorne. 1974 and Eudorylaimus diadesatus (Cobb in Thorne & Swanger. 1936) Andrassy. 1959
E. monohvstera E. diadematus Ch;be National Park Chobe National Park --Kwai River Delta Okavango
n 14 H 8'f-'fo 2!f¥ 1 .\i-
L (0101) 1,06(1.00-1,18) 1,56(1,46-1,70) 1,26 & 1,29 1,18 a 34,6(29,2-39,3) 30,7(26,7-33,5) 30,7 & 26,3 22,7 b 4,3(3,9-4,8) 4,00,9-4,2) 3,7 & 3,7 3,6 c 31,8(27,5-38,2) 28,8(24,3-39,0) 24,7 & 28,7 34,7 c' 1,7(1,3-2,0) 2,2(1,7-2,5) 2,1 & 2,0 1,2 V% 37,4(35-41) 51(49-52) 52 & 52 52 Lip region width 11,2(11-12) 16( 15-17) 15 & 14 17 height 4,2(4-5) 5,4(5-6) 5 & 4 5 Odontostyle length 11,7( 11-13) 17(17-18) 18 & 16 18 width 1,9(1-2) 2,9(2,5-3,0) 3 & 3 2,5 Odontophore length 20,9(18-26) 30.5(28-32) 29 & 25 36 .;.. Total stylet length .;.. 32,4(29-38) 47,6(45-49) 47 &41 54 Stylet aperture length 3,2(3-4) 8,6(8-9) 9 & 9 8 % of stylet length 25,4(23-36) 50(47-53) 50 & 56 47 Guiding ring from anterior end 6,4(5-7) 8,9(8-10) 8 & 7 9 Amphid aperture length 5,5 & 6,0 (n • 2) 9(8-11) 9 &- 10 % of lip region width 49 & 54 (n • 2) 58,7(47-67) 60 &- 59 Oesophagus length 248(230-260) 338(250-420) 340 & 350 330 Basal bulb length 94,0(85-107) 195(178-220) 172 & 172 153 Nerve ring from anterior end 98,8(85-106) 133(123-143) 133 & 117 131 Lateral chord % of body width 12,6(6-18) 16(10-20) 22 & 24 15 Tail length 33,6(28-40) 56(42-63) 51 & 45 34 Prerectum length 44,7(42-55)* 80(62-92) 68 & 76 52 iRectulll length 24,9(19-30) 41(36-49) 38 & 76 38 Cuticle: neck - 3 3 & 3 3 mid-body - 3,3(3-4) ::I & 5 3 anterior to anus - 3,4(3-4) 4 & 4 4 around tail tip - 16,3(13-18) 17 &11 13
* n· 11 TABIB 2: !hl"..et::ric data of LaIxmeaa lIIIIJrlt:1eDse vuuans. 1959
Chvango M:lremi ~ River Delta
n 414' 1~ 1~ 1 O'
L (m) 1,37(1,29-1,45) 1,57 1.43 1,38 a 26,9(26,(}-28,2) 24,2 28,0 28,1 b 4,1(3,8-4,4) 4,7 3,97 4,1 c 51,4(46-58) 56,1 46,1 53,1 c' 0,96(0,9-1,0) 0,97 1,1 0,96 V% 56,3(5~57) 58 57 - Up regioo wi
.£.:.~ .£.:. bulbiferus
Chobe National Park Okavango Serondella Sawti Marsh Morellli Okavallgo
11 2~ 1~ 4U, 1 ~ 1 ~ 1 ~
L (mm) 0.97 0.80 1,60(1,53-1,63) 1,36 1,44 1,46 a 31,3 & 32,3 33,3 52,4(47.8-55,9) 59,1 45,0 48,7 b 3,9 3,4 5,2(4,9-5,4) 4,3 4,6 4.4 c 37,8 & 38,8 27,6 38,3(36,4-40,8) - 36,9 29,2 0' 1,2 & 1,3 1,7 2,5(2,3-2,5) - 2,2 2,7 ~% 43 44 45 ,5(43-48) 49 49 43 ~ip region ~idth 17 16 11,5(11-12) 9 12 12 height -- 4 4 3 4 ~ Iodontostyle length 12 & 14 12 11(10-12) 10 12 12 0) ~idth 2 & 1,5 2 1,5(1-2) 1 1,5 1,5 Iodontophore length 25 & 19 17 17,8(13-20) 18 20 - ~ota1 stylet length 37 & 33 29 28, 8( 24-32) 28 32 - Stylet aperture lellgth 7 & 9 8 5,5(5-7) 5 6 6 % of odontostyle 58 & 64 67 49,5(45-58) 50 58 50 ~uiding ring from anterior end - & 6 6 5(4-6) 4 6 - ~phid aperture length - & 5· 7 5,5(5-6) - - - % of lip region ~dth - & 29 44 50(45-55)- - - - Oesophagus length 250 220 305( 300-310) 320 310 330 Basal bulb length 133 & 134 122 160( 155-164) 173 161 148 Nerve ring from anterior end 80 & 81 71 99,8(95-113) 94 157 119 Lateral c:hord % of body ~dth 44 & 27 25 16,8(13-21) 17 16 20 Tail length 26 & 25 19 41,8(40-43) - 39 SO Pre rectum length - 17 14 - 29 - Rectum length 15 12 19(15-24) - 27 20 Gl 71 & 72 55 102(85-118) 112 102 - G2 66 58 102(78-115) 114 99 - Anterior ovary length 35 28 46,5(45-48) 44 39 - Posterior ovary length 39 & 38 39 50( 45-55) - 54 -
- 11· 2 'mII.E 4: ltliP"eI I Ie data of ..., pcpJ!atlaw (r-l.es aaly) of Dism1a1glls p!!tl!!jar ax-. 1966lD1 of Dfsmla1!11!11 ~ 'I1mme. 1939
-r-. D. pwmajor !:"lIBjor
Oxlamls (1966) 'Ib:mle (1939) Olamns (1966) Hl!yns (1963) Botha & Hl!yns (1990b) Sauer & ADnells (1985) Preseot spec:IlII!IlS fraD Botswaoa
CcDgo Utah Utah Transvaal & Kruger National Park Australia Seraxlella SawC. Marsh Cape
n 6.'A'A 7 :j... 18 # 7# 3i'l'- 25 'Ai- 4# 1 ...
L (m) 1,64(1,34-1,98) 1,9-2,5 1,83-2.24 1,73-2,40 1,93-2,20 1,71(1,45-1,88) 1,63(1,62-1.64) 1,65 a :xl,5(26-3S) 33 - 29-38 39-44 33(27-41) 40,8(39,0-41,8) 41,3 b 3,8(3,4-4,3) 4,0-4,7 3.7-4,6 3,4-4,5 4,2-4,5 4,2(3,8-4,5) 4,0(3,8-4,2) 4,1 e 55(45-72) 67-83 - 74-76 71~ 81(73-91) 53,2(49,7-54,6) 51,6 <:' [0,7&0,8] - - - 0,88-1,0 0,9(0,8-1,0) 1,2(1,2-1,3) 1,3 .....,~ V% 49,3(45-52) 52 49,5-55 51-56 47-55 52,5( 49-56) 51,.5(50-53) 51 Up teg1cn width 29(27-32) - -- 24-30 [28,2) 24,.5(23-26) 2S ()jootostyle lerlgth 26,3(25-28) - 25-29 - 20-22 27-WX 19,.5(19-21) 19 Width [3,5] - - - 3-3,5 [3,5] 2,8(2-3) 3 Qlootophore lerlgth 43,3( 40-48) - J8-48 - 35,5-42.5 34(32-36) 33,5(32-35) ::0 Total stylet length 69(65-74) - 66-74 - 55,5-64,5 - 53(51-54) 55 Stylet apertllre length [10&12) - - - - [l4] 10,5(1D-ll) 11 %of lItylet length [~] - - - SS-58 [63) 54(52-58) 58 Qlid.1ng ring fraD anterior en:1 [15,3] - - - 7,5-10,0 [10] 8,3(7-10) 7 JIqlhid apertUre length [8,2J - - - 7-9 [5,9J 8,3(7-9) 7 %of Up teg1cn Width [29J - - - - [21J 33,8(30-38) 28 Oesophagus lerlgth - - - - 435-520 [406] 413(390-430) 400 Basal lJJlb length - - - - 224-328 [234J 252(234-282) 228 Nerve ring fran anterior en:1 - - - - - [142) 122(117-130) 123 L'lteral dlOtd. %of body 'l1dth - - - - - [2S] 18.3( 15-21) 2:l 'll:I.1l length 28-33 - 24-33 - 23-31 [21,2) 30,8(30-33) J2 Prerectun length - - - - 34 - 21(17-23) JJ Rectum length - - - - 22-34 [16,5J 25,3(23-28) 'lJ
[] • calc:ulated fran the or1g:I.nal 1llust:r:1ticn • • C'mil1Dat1a1 of two popuL1t1alS (Lewistcn 3lJ:i Salem),sped1lBIs fran the or1g:I.nal aill.ec:ticn of G. nmne X • Paratypes lCC • lb average given ':tWB s: }b:.i....dc data of Apom:" ai!!Pllns adrlaaoi Jlot!B & Beyos. 1990 aDd Apom:laineJJns pnpfllahlll (l!ast:Lan. 1865) Baqrl. & Ihem. 1975
!.adr:I.aani ~ paoillaOJS
Present spec:Im!ns nmoe & S;oaoger (1936) Present spedlIB1S
Ckavango Broadlmor. EbglaOO COObe NatiCXla1. Park
n 2-¥¥ 300 1 'f. 1 o 2-¥¥ 200'
L (mn) 1.65 &1.88 1.70(1.63-1.79) 2.8 2.4 2.20 &2.14 2.12 &2.23 a 43.4 &45.9 43.7(42•.3-44.8) 30 28 40.0 &40.4 41,6 &42,9 b 4,2 &4.9 4,6(4,1-5.1) 4.3 4.1 4,5 &4.2 4,4 &4,8 c - &67,1 68,5(63,9-74,0) 67 59 75,9 &64,8 75.7 &92,9 c' - &1,12 1,01(0,88-1.12) [0.9] [0.8] 0,9 &0,97 0,85 &0,8 V% 54 &55 - 49 - 49 &49,S - Up reg:l.cn width 13 &12 12,7(12-13) [16] - 15 &16 17 &16 height 5 &5 5 [5] - 5 &5 4 &5 Cdcntostyle length 13 &12 11,3(11-12) [21] - 16 &16 15 &14 ~ width &4 3 &4 CO 3 &3 3 [3.5] - 3 Cdcntophore length 24 &18 23 &17* - - 27 &26 26 &27 Total stylet lecgth 37 &30 34 &28* - - 43 &42 41 &41 Stylet aperture length 7 &7 7 [11] - 9 &9 8 &8 %of odcntostyle 54 &58 62(58-64) [52] - 56 &56 53 &57 Q1iding ring fran anterior en:! 7 &5 5 &6* [10] 8 &7 8 &8 x . - ~h1d aperture length 7 &- 7 [9] 8(0-1) 9(0-1) x - %of lip regl.cn width 54 &- 54 [60] - 53(0-1) 56(0-1) Oesophagus length 390 &380 37J(J.5()-400) - - 480 &510 480 &460 Basal t:u1.b length 180 &167 180(161-205) . - - -- Nerve ring fran anterior en:! 113 &130 123(121-126) - - 1SO &140 144 &145 L1teral chord : of I:xxiy width 11 &17 14,7(11-18) - - 18 &13 16 &10 TaU lerlgt1l - &28 25(22-28) [23) [20] 29 &33 28 &24 Prerect1.m length - &92 163 &188 - - 191(0-1) - Rect1.m length - &38 - [36) - 40 &43 - Spi01l.lIII length - 43,7(43-45) - [52] - 57 &61 Lateral guiding piece l.ecgt1l - 10 &11 - [10] - 15 &17 N.mber of vent:raredian supple- - 5 - 8 - 5 &5 IIBlts
* n· 2 x n· 1 [ l > calo.tlate:i fran the original illustr:1tioos IABLE 6: }t)rplY'!!f!td.c data of Apam:lafneJlns m1ct'O{XD:tatus Botba & Be,Ds. 1990
sercme.ua savuti M3rsn Bobs Is.J..an:1 n 4¥¥ 1 0 1 -¥- 7!# 200' L (11m) 2,10(1,80-2,39) 2.84 2,42 2,38(1,88-2,64) 250 & 258 a 27,2(25,0-31,9) 41,8 24,7 28,7(22,8-34,2) 32,1 &34,4 a' 30,5(27,9-31,9) - 33.6 34,4(25,7-38,3) 38,5 & 39,7 b 3,87(3,46-4,35) 4.9 3,9 4,0(3,7-4,3) 4.63 & 5,16 c 53,0(40,9-63,2) 83,5 65.4 75.2(66.5-86.2) 75.8 &83,2 c' 1.0(0.8-1.2) o,n 0.9 0.76(0,7-0.9) 0.8 & 0.8 V% 54,1(52.3-55,8) - 58 52,9(49,8-56.0) - Lip reg1.oo width 18.8(17-20) 18 19 21,3(20-23) 21 &22 height 6(5-7) 6 6.5 6.3(6-7) 6,5 & 6,5 Odontostyle length 20.5(20-21) 21 20 21.4(19-22) 22 &23 ~ (0 width 4.3(4-5) 5 4,5 4.4(4,0-5.5) 5 &5 O:lontophore length 39(36-44) 40 43 40(39-42) 38 &35 Total stylet length 59;5(56-64) 61 63 61,4(59-64) 60 &.58 Sl:'.Ilet aperture length 10.3(11-13) 10 13 . 13.3(12-15) 14 &16 %of odontostyle length 58.5(52-65) 48 65 62(59-68) 64 &69 Qliding r1Dg from anterior erxi 13(12-14) 10 12 12.6(10-15) 10 &11 ~hid aperture length 10,3(10-11) - 10 10,8(10-11) 12 &13 %of lip region width 55(50-61) - 53 SO.3(45-52) 57 & 59 Cesophagus length 540(520-570) 580 620 601(490-690) 540 s seo Basal Wlb lEDgth 260-270* 255 - 297(230-350) 260 &240 Nerve ring frail anterior erx1 175(166-185) 169 192 183(161-202) 165 &164 lateral chord %of body width 13,8(12-16) 10 15 9(7-11) 4 &8 TaU length 40(34-44) 34 37 31.9(26-38) 33 &31 Prerectumlength 105(71-129) - 120 121(n-138) 222 &247 Rectum length 54.5(51-56) - 59 57(40-63) - &- SpiOJ.1.un length - 79 -- 82 &87 lateral guiding piece length - 18 - - 24 &22 rbOOer of vmtraIEdian supplements - 9 - - 7 &8 * n· 2 'mIIl:B 7: KxJ,Jlaet, Ie data of llpom'Jal....Un& para1?R!rl11at11S llotba & Beyos. 1990 I Botha & Heyn:i (1990) Present specimens I Kruger Natiooal Park <:robe Natiooal Park Okavaogo 0 lli:llOcype 2¥¥- 3cn 1 ¥- 2 (Xl 2¥¥- 10' L (DID) 2,51 2,11 & 2,40 2,27-2,38 2,57 2,49 &2,59 2,61 &2,79 2,62 a 33 32 &29 24--32 36,2 33,6 &32.4 37,8 &31,3 34,9 b 4,4 3,9 &4,9 4,2-4,5 3,9 4,3 &4,2 5,1 &4,7 4,9 c 71 62 &75 60-64 95,2 80,3 &60,2 70,1 &68,0 60,9 c' 0,92 0,98 &0,86 0,9.5-0,98 0,6 0,72 &0,82 0,8 &0,9 0,9 vr. 52 55 &56 - 54,8 - 52,2 &54,1 - Lip reg1cn width 19,5 20 18-20 20 20 &20 21 &23 23 height - [7,6] - 6 7 &6 8 & 7 8 ()jootostyle length 19 18 16-18,5 19 19 &19 22 &21 22 (J1 width 4,5 5 &4,5 4-5 4,5 5 &5 5 &5 5 o Q1cntophore length 32 32 26,5-36 38 37 &38 37 &38 36 Total stylet length 51 50 44-54.5 .57 56 &.57 59 &59 58 Stylet apertUre lecgth 13 12 11-12,5 9.5 8 &9 15 &15 14 %of stylet length 68 67 68-69 47 42 &47.4 68 &71 63.6 Mding r1ng frall anterior eOO 9.5 10.5 & 9 8-10 12 9 & 7 13 & 13 13 ~hid apertUre leDgth 9 9 9-10 12 9 &- - &12 10 %of lip reg:l.cn width - - - 60 45 &- - &52 43.5 Oesopmgus length .570 530 & 490 540-555 6.50 .580 & 610 510 & 590 540 Nerve r1ng fran anterior em - (171) - 178 163 &168 167 &187 - Lateral chord %of body width - - - 5,6 8.1 &- 5.7 & 6.7 9,3 Till leogth 35,5 33,5 &32 36-37,5 27 31 &43 33 & 41 43 Prerectlm length 173 136 & 147 139 (0" 1) 244 262 &- 146 &88 - Rectum length 48 46 &47 62 (n « 1) 51 .57 &- 50 &58 - Spiculum length - - 80-88 - 75 &83 - 89 Lateral guiding piece length - - 19-23 - 17 &- - 22 N.miJer of wntraned1an supplements -- 15-17 - 10 &- - 10 ~ 8: Mlcplncetrlc: data of~.l.aimJs usit:atoides spec. oov. Holotype Paratypes n ~ 7H 5 6 L (am) 1,14 1,230,17-1,29) 1,20(1,14-1,32) a 40.7 41.0(39.D-46.3) 38.7(37.4-40.4) b 4.6 4.8(4.5-5.2) 4.8(4,4-5.1) c .13.7 14.6(12.5-18,4) 75,4(72.5-81,4) c' 4,6 4.8(3.7-5.7) 0.82(0,7-0,9) V% 53 49,4(47-53) - Lip region width 12 10,9(10-11) 10,8(10-11) height 4 3,8(3-+) 3.6(3-4) Cdcntostyle length 13 13,3(13-14) 12(11-13) ~dth 2,0 1.90.0-2,5) 1,8(1,0-2.0) Cdcntophoce length 19 18(17-19) 18.4(17-20) Total stylet: length 32 32.3(30-38) 30,4(29-32) St'Jlet aperture length 4 5(4-6) 4,6(4-6) ...... U'1 %of stylet length 38 40(31-50) 38(33-46) Q.licling ring fran anterior end 7,5 7.3(7-8) 6,8(6-7) Amphid aperture length 7 6(n = 1) 6(5-7)* %of lip region width 56 55(n =1) 56,7(45-70)* oesophagus length 250 259( 240-280) 252(240-260) Nerve ring from anterior end. 100 96(89-107) 93,6(88-100) Lateral chord %of b:xly width 28 21,4(1&-27) 25,8(17-30) Tail length 83 85,5(7o-103)x 16(14-18) Prerectum Length 43 49.4(45-55)0 71(64-79) Rectum length 28 27.8(2...0:;....30)0 35.5(34-37) Spial1.um length - - . 33.4(31-36) Lateral guiding piece Iength - - 6.6(5-9) N..mDer of ventrcm:di.an supplEm!l1t:i - - 8.4(7-10) \ o n = 5 ." n::i J x n =6 Figure 1: Ecumenicus monohystera (de Man, 1880) Thorne, 1974 A. Anterior region B. Female posterior region (caudal papillae indistinct> c. Reproductive system o and E. Variation in oesophago-intestinal junction F. Heat-relaxed body postures - 52- B E o ,25!Jm .1mmL...;...... ;;,;.: ...... J,F Figure 2: Eudorylaimus diadematus (Cobb in Thorne & Swanger, 1936) Andrassy, 1959 All specimens from the Chobe National Park, except 0, which is from the Okavango A. Head and neck region B. Female posterior region C. Anterior reproductive branch O. Variation in female posterior region E. Heat-relaxed body postures F. Variation in shape of amphid - 53 - B u. c I oCt w EEE o 0 E 10 10 o E ((G ~ F Figure 3: Labronema mauritiense Williams, 1959 A. Specimen from Moremi; Band F. Okavango; C-E. Kwai River A and B. Variation in female posterior region C. Male posterior region D. Sperm cells E. Lip region and amphid F. Juvenile tail - 54- A F o E ,SOum A-D,F Figure 4: Discolaimus brevis Siddiqi, 1964 All specimens from Chobe National Park, except C, which is from the Okavango A. Head region Band C. Shape and position of amphid D. Lateral chord with hypodermal glands E. Reproductive system F. Female tail G. Oesophago-intestinal junction H. Heat-relaxed body postures - 55 - B c E I, :d~~tft{" 0 II ,I II 1\ I' II II II II ,I I' ,I II II I' /1 II "II ,1 II II II I' II d F I' G L!..!:!!!!!.. ~I H L£.!!..I!.!!!- ~I A-G Figure 5: Discolaimus major Thorne, 1939 A. Anterior region B. Oesophago-intestinal junction C. Female posterior region D. Lateral chord with hypodermal glands E. Vulva region F. Heat-relaxed body postures - 56 - A B c zs um o E F Figure 6: Aporcelaimellus adriaani Botha & Heyns, 1990 A. Head and neck region B. Head region C. Male posterior region D. Posterior reproductive branch of female E. Female posterior region F. Male posterior region G. Heat-relaxed body postures H. Variation in arrangement of supplements - 57 - D H G , ,2Sflm ( SOpm --- ,C,E,F , 100 l':.:.;mo--_ JH ,SOflm 'A,D , lrnm Figure 7: Aporcelaimellus micropunctatus Botha & Heyns, 1990 A-E. Specimens from Chobe National Park, G and H. Specimens from the Okavango A. Head region B. Oesophago-intestinal junction C. Posterior reproductive branch of female D. Sperm cells E. Female posterior region F. Heat-relaxed body postures of females (specimens of both populations) G. Male posterior region H. Female posterior region I. Heat-relaxed body posture of male - 58- 8 c E ,50pm 1 25 pm o @~ @@ f0@ ~ @@ G 6e>~ F Figure 8: Aporcelaimellus papillatus (Bastian, 1865) Baqri & Khera, 1975 A. Anterior region B. Female posterior region C. Anterior reproductive branch D. Oesophago-intestinal junction E. Shape and position of amphid F. Male posterior region G. Heat-relaxed body postures of males H. Heat-relaxed body postures of females - 59 - B o H Figure 9: Aporcelaimellus parapapillatus Botha & Heyns, 1990 A,B,D,E and J. Specimens from the Okavango, C and H. Specimen from the Chobe National Park A. Head and neck region B. Shape and position of amphid C. Male posterior region D. Anterior reproductive branch of female E. Female posterior region F. Heat-relaxed body postures of males G. Heat-relaxed body postures females H. Lateral chord I. Sperm cells J. Variation in female tail - 60- F @ H J Figure 10: Mesodorylaimus usitatoides spec. nov. A. Head and neck region B. Head region C. Female posterior region D. Anterior reproductive branch of female E. Male posterior region F. Spiculum and lateral guiding piece G. Heat-relaxed body postures of males H. Sperm cells I. Heat-relaxed body postures of females J. En face optical section through vagina K. Variation in oesophago-intestinal junction - 61 - c D E IJ A,C,D,H,K IB,F ,1mm_____ - .G,t K I Figure 11: Prodorylaimus/Laimydorus species A. Head and neck region B. Female posterior region C. Head region D. Anterior reproductive branch E. Tail end F. Heat-relaxed body posture G. Lateral chord - 62- 8 I 100..l!u~me:-__ ,A .50 urn ,C,E G ,100um ,B ,SOum .SOum ,lrn_m_ IF CHAPTER TWO One new and three known Dorylaimida species from Botswana (Nematoda: Dorylaimida) ABSTRACT Four Dorylaimida species are reported from Botswana: Proleptonchus dieteri spec. nov. is comprehensively described and illustrated, while brief descriptions, measurements and illustrations are given for Eudorylaimus amabilis (Jairajpuri, 1965) Siddiqi, 1966, Lepton- chus transvaalensis Heyns, 1963 and Tyleptus striatus Heyns, 1963. UITTREKSEL Een nuwe en drie bekende Dorylaimida spesies vanaf Botswana (Nematoda: Dorylaimida) Vier Dorylaimida spesies word uit Botswana aangemeld: Proleptonchus dieteri spec. nov. word volledig beskryf en afgebeeld, terwyl kort beskrywings, afmetings en illustrasies gegee word vir Eudorylaimus amabilis (Jairajpuri, 1965) Siddiqi, 1966, Leptonchus transvaalensis Heyns, 1963 en Tyleptus striatus Heyns, 1963. INTRODUCTION In a previous paper the author reported on various DoryJaimida collected during a survey conducted in Botswana during July and August, 1989, mainly from the Okavango Swamps, Chobe National Park and the Moremi Wildlife Reserve (De Bruin & Heyns, in press). The present paper is the second report on this group of nematodes, which consti- - 63 - tutes the largest number of genera found in this region. MATERIALS AND METHODS Specimens were killed in water by gradual application of heat, fixed in FAA, processed into glycerine according to Thorne's (1961) slow method and mounted on permanent slides. Measurements and drawings were done with the aid of a Zeiss Standard 18 research microscope, equipped with a drawing tube. The body posture and all curved structures were measured along the median line. Slide numbers refer to the nematode collection of the Department of Zoology, Rand Afrikaans University. TAXONOMY Eudorylaimus amabilis (Jairajpuri,1965) Siddiqi, 1966 Syn. Qudsianema amabilis Jairajpuri, 1965 (Figure 1) Measurements Females (n = 2): L = 0,72 & 0,66 mm; a = 28,8 & 28,0; b = 3,3; c = 16; c' = 2,8 & 3,5; V = 51,3 & 52,0 %; odontostyle = 13 & 12 pm; odontophore = 22 & ? pm; total stylet length = 35 & ? pm; tail = 45 & 46 pm Description Body short and slender. Heat-relaxed body posture slightly curved ventrad, more so in posterior region. Cuticle with minute striations, visible mainly on neck region. Cuticle 1 pm thick on neck, 1,5 pm at midbody, 2,1 pm around tail tip. Lateral chord 6-9 pm wide or 25-36 % of the corresponding body width. Body pores indistinct. - 64 - Lip region set off by a constriction, 12 pm wide, 7 pm high. Lips well separated. Labial papillae protruding, resulting in lips having an angular appearance; number and arrangement of labial papillae dorylaimoid. Amphid aperture a slit, 6 pm wide, situated at level of con striction between lip region and adjoining body. Fovea funnel-shaped. Fusus and sensilla not observed. Length of odontostyle about equal to lip region width. Stylet aperture 31-33 % of odontostyle length. Guiding ring single, sclerotized, 7 pm from anterior end. Nerve ring 85-88 pm from anterior end, nerve cells distinct. Hemizonid and hemizonion could not be seen. Oesophagus 200-220 pm long, anterior part not very slender, widening gradually to form the basal oesophageal bulb. Oesophageal gland outlets and nuclei indistinct except dorsal gland outlet and nucleus, situated at 61,7-65,1 and 68,2-68,6 % of total neck length, respectively. Distance between DO and ON is 3,5-6,5 %. Cardia 8,0-10,5 pm long, 7 pm wide. Intestine four cells in circumference, intestinal wall containing yellowish granules. Prerectum 39-41 pm or 2,4-3,1 times the anal body diameter. Rectum 17 pm or one and one third times the anal body diameter. No rectal glands could be seen. Prerectum of one specimen differentiated into two distinct parts, the posterior part forming a thin walled chamber (Figure 1H). Tail elongate-conoid, slightly curved ventrad, more so in second specimen (Figure 1G). Tail tip rounded, variable (Figure 1G and H). Caudal papillae inconspicuous, except in one specimen where one pair could be seen. Reproductive system didelphic-amphidelphic. Anterior and posterior branches 37-48 and 45-48 pm long or occupying 5,6-6,6 and 6,6-6,9 % of total body length, respectively. Ovaries reflexed, anterior and posterior ovary 23-24 pm and 24-29 pm long, respectively. No sphincter muscle could be seen between uterus and oviduct, and partes dilatata were not evident. Uterus weakly developed, oviduct short and wide. No sperm cells or uterine eggs present. Vagina occupying 23-33 % of corresponding body width. Vulva a transverse slit; lips without sclerotization. - 65 - Male and juvenile Not found. Locality and habitat Two females from Boba Island (near Jedibe) in the Okavango Swamps, from soil among the roots of herbaceous plants and palm trees, collected by A. Coomans and J. Heyns 31 July 1989. Specimens On slides RAU 5229 and 5231. Remarks The specimens from the Okavango agree with the original description except for broader lips and longer odontostyle. It should be noted that when Siddiqi (1966) studied topotvpes of this species, he did not find the bibulbar bulbus and flanged odontophore mentioned in the original description. In length of odontostyle and tail, the Botswana specimens are closer to Siddiqi's (1966) topotypes (12-13 pm vs 10,4 pm and 45-46 pm vs 49,8 pm, respectively). The scale given with Jairajpuri's (1965) Figure 1D is apparently incorrect, since this gives a calculated tail length of 20 pm, whereas tail length calculated from his L and c-ratio is 50-53,6 pm. Proleptonchus dieteri spec. nov. (Figure 2) Measurements Holotype female: L = 1,55 mm; a = 43; b = 7,0; c = 77,5; c' = 0,8; V = 57 %; odontostyle = 11 uttv; odontophore = 11 uttv; total stylet length = 22 pm; tail = 20 pm - 66 - Paratype females (n = 2): L = 1,68 & 1,93 mm; a = 42 & 44,9; b = 7,0 & 8,8; c = 88,4 & 68,9; c' = 0,7 & 0,8; V = 52 & 54 %; odontostyle = 9 & 8 pm; odontophore = 11 & 12 pm; total stylet length = 20 pm; tail = 19 & 28 pm Paratype males (n = 3): L = 1,58 (1,55-1,63) mm; a = 45,7 (43,1-49,4); b = 6,5 (6,3 6,8); c = 66,9 (62,4-70,9); c' = 1,03 (1,0-1,1); odontostyle = 8pm; odontophore = 10 (9-11) pm; total stylet length = 18 (17-19) pm; tail = 24 (23-25) pm Description Female Body posture of heat-relaxed specimens straight to slightly curved ventrad. Exocuticle and mesocuticle appearing to be smooth, endocuticle coarsely striated and sometimes irregularly separated from rest of cuticle. Radial elements present over entire body, irregu larly spaced, more distinct towards head and tail region, appearing as punctations when seen en face. Crystalloids present in cuticle over entire body, but more abundant towards the tail region. Body pores indistinct. Lateral chord 9,7 (9,0-10,0) pm wide or 25 (23-28) % of corresponding body width. Lip region rounded, slightly offset from adjoining body, 11,7 (11,0-12,0) pm wide, 4,7 (4,0-5,0) pm high. Lips not very distinct, appearing to be amalgamated. Labial papillae distinct. Amphid aperture 10,5 pm wide (n = 2) or 87,5 and 95 % of lip region width. Amphidial fovea funnel-shaped; fusus with sensilla not visible. Stoma flask-shaped, dis tinctly sclerotized. OdontostyJe slightly arcuate dorsad; stylet aperture indistinct. Odon tophore simple, arcuate ventrad in one specimen. Guiding ring single, sclerotized, 8,3 (8,0 9,0) pm from anterior end. Nerve ring encircling anterior part of oesophagus 98 (89-105) pm from anterior end. Hemizonid situated at level of nerve ring. Hemizonion not seen. Anterior slender part of oesophagus less muscular and separated from basal bulb by - 67 - a slight constriction at 82 (80-85) % of total neck length. Basal bulb 42 (40-43) pm long, pear-shaped in one paratype specimen (Figure 2F), more elongated in others. Dorsal oesophageal gland nucleus and a single subventral pair of gland nuclei could be seen at 85,7 (83,3-87,4) % and 93,7 (92,3-94,4) % of total neck length, respectively. All outlets indistinct. Cardia varying in shape and size, 11 (10-12) pm wide, 10 (9-12) pm long. Intestine four cells in circumference. Prerectum 157 and 159 pm (n = 2) or 6,5 and 4,8 times the anal body diameter. Rectum 36 pm (n = 1) or one and a half times the anal body diameter. No rectal glands seen. Tail short, conoid and bluntly rounded. Caudal papillae indistinct. Reproductive system pseudomonodelphic. Anterior reproductive branch well developed, 476 (445-528) pm long. Posterior branch with a well developed uterus, 208 (138; 236; 251) pm long or 3,0; 5,6 and 5,9 times the vulval body diameter. A reduced oviduct or an oviduct and ovary in vestigeal condition is present, separated from uterus by a distinct sphincter muscle in paratype specimens (Figure 2C and D). Vulva a transverse slit with slightly sclerotized lips. Vagina muscular, 12 and 16 pm (n = 2) long or 29 and 36 % of corresponding body width. Uterus of anterior reproductive branch 113,7 (8;3-156,0) pm long, without a distinct pars dilatata uteri. Conspicuous sphincter muscle present between uterus and oviduct. Pars dilatata oviductus filled with sperm cells in all specimens. Ovi duct well developed, 243 (215-283) pm long. Ovary 291 (185-386) pm long. reflexed, ovarial sac conspicuous. Numerous oocvtes present. One egg measuring 81 x 37 Jim present in uterus in one paratype specimen. Sperm cells present in the posterior uterus in two specimens (Figure 2B and D). Male Similar to female, except body posture of heat-relaxed specimens posteriorly more strongly curved ventrad. Reproductive system diorchic, testes opposed, outstretched. Anterior and posterior testes 262 (238-290) pm and 255 (222-284) Jim long, respectively. Sperm cells - 68 - ovoid, about 5 pm long. Junction between vas deferens and prerectum distinct. No muscular ejaculatory duct present. Ejaculatory glands conspicuous in one specimen. No rectal glands could be seen. Spicules arcuate, 39 (37-42) pm long. Lateral guiding pieces 9 and 10 pm (n = 2) long. Supplements mammiform, consisting of an adanal pair situated anterior to cloacal opening and a row of five irregularly spaced, non-contiguous ventromedian ones. Copulatory muscles reaching up to anteriormost ventromedian supplement. Tail similar to that of female. Two pairs of caudal papillae present. Juvenile (?Third stage) (n = 2): L = 0,92 & 1,13 mm; a = 31,7 & 36,4; b = 4,8 & 5,4; c = ? and 66,5; c' =? & 0,9; odontostyle = 8 pm; odontophore = 9 pm; total stylet length = 17 pm; replacement odontostyle = ? ; tail = ? & 17 pm General morphology of juveniles similar to adults. The replacement odontostyle could not be seen in any of the specimens. Type locality and habitat All specimens from wet soil among the roots of a sausage tree (Kigelia africana) at the waterside on Boba Island, Okavango Swamps, collected by A. Coomans and J. Heyns 1 August 1989. Type specimens Holotype female second specimen from left on slide RAU 5276, paratype females on slide RAU 5276, paratype males on slides RAU 5275 and 5278, juvenile on slide RAU 5277. Diagnosis Proleptonchus dieted spec. nov. can be recognised by the relatively long body (1,55-1,93 mrn), post-equatorial vulva position (52-57 %), basal bulb 40-43 pm long, and posterior - 69 - reproductive branch with reduced oviduct, the branch 3,0-5,9 times the vulval body width. Relationships P. dieteri spec. nov. can be compared with Proleptonchus johnsoni Goseco, Ferris & Ferris, 1974, but differs in having a longer body (1,55-1,93 mm vs 1,1 and 1,32 rnrn), somewhat greater a-ratio (42,0-44,9 vs 37,0 and 39,3), greater b-ratio (7,0-8,8 vs 6,9 and 6,4), longer tail (19-28 pm vs 13,8 pm (calculated from the original Figure 11 C of Goseco, Ferris & Ferris, 1974a), smaller c-ratio (0,7-0,8 vs 1,3), longer basal bulb (40-43 pm vs 31,9 pm) and by the presence of males. The new species corresponds to Proteptonchus saccatus (Clark, 1962) Andrassy, 1963 in body length. It differs, however, by the greater a-ratio (42,0-44,9 vs 30,1 in females, 43,1-49,4 vs 33,4-34,2 in males), much smaller c-ratio (68,9-88,4 vs 105,6 in females, 62,4-70,9 vs 88,5-97,1 in males), shorter basal bulb (40-42 pm vs 54,4 pm in females, 40-45 pm vs 51,2-53,0 pm in males) and shorter spicules (37-42 pm vs 48-49 pm). P. dieteri spec nov. comes close to Proleptonchus clarus Timm, 1964 in body length, b, c and c' longer basal bulb (40-43 pm vs 35,9 pm in females, 40-45 pm vs 33,6 pm in males), slightly shorter lateral guiding pieces (9-10 pm vs 12-14 pm) and the presence of only five ventromedian supplements vs seven to eight in P. clarus. P. dieteri spec. nov. corresponds to both Proleptonchus aestivus Lordello, 1955 and P. weischeri Goseco & Ferris, 1967 in length of basal bulb, but differs from the former by the longer body (1,55-1,93 mm vs 1,19-1,5 mm), greater a-ratio (42,0-44,9 vs 27,4-35,0), presence of a reduced oviduct and presence of males (measurements by Jairajpuri, 1964 were. also taken into account). From the latter species it differs by the longer body (1,55 1,93 mm vs 1,30-1,48 mm in females, 1,55-1,63 mm vs 1,36-1,43 mm in males), greater - 70- a-ratio (42-45 vs 33,0-33,8 in females, 43,1-49,4 vs 34,3-38,6 in males) and longer and differently shaped tail (19-28 pm vs 14,5-17,6 pm in females, 23-25 pm vs 19,2 pm in males and tail shape hemispheroid in P. weischerh. P. dieteri spec. nov. can also be compared with Proleptonchus shamimi Bajaj & Bhatti, 1980 but is slightly longer (1,55-1,93 mm vs 1,14-1,47 mm in females, 1,55-1,63 mm vs 1,10-1,50 mm in males), has a greater a-ratio (42,0-44,9 vs 28-37 in females, 43,1 49,4 vs 31-40 in males), slightly greater b-ratio in females (7,0-8,8 vs 5,5-6,8), longer female tail (19-28 pm vs 11-18 pm), slightly longer basal bulb (40-45 pm vs 30-38 pm) and longer spicules (37-42 pm vs 28-34 pm). Remarks Bajaj & Bhatti (1980) examined 48 specimens of P. shamimi and found a great variation in length of the posterior reduced reproductive branch (1,8-7,8 times the vulval body dia meter). They consequently concluded that the length of the posterior reproductive branch or postvulval uterine sac may be of little value in differentiating species of Proleptonchus, except in two species viz. P. aestivus Lordello, 1955 and P. brevisaccus Goseco, Ferris & Ferris, 1974, where males are rare and the posterior branch is less than one vulval body width long. The author tends to agree with them, considering the rather great variation in length of the posterior branch in the new species (3,0-5,9 times the vulval body width). Bajaj & Batti (1980) surmised that the variation in length of the posterior branch may be attributed to the presence or absence of sperm cells in the uterus. This is not borne out by the present specimens, where sperm cells are present in the posterior uterus of both the specimen with the shortest and the specimen with the longest posterior branch (Figure 2D and B, respectively). In the third specimen with posterior branch length of 236 um, no sperm cells are present (Figure 2C). - 71 - Leptonchus transvaalensis Heyns, 1963 (Figure 3A-G) Measurements Females: (n = 2): l = 0,80 & 1,01 mm; a = 24,2 & 28,9; b = 4,2 & 5,2; c =50,0 & 45,9; c' = 0,8 & 0,9; V = 61 & 58 %; odontostyle = 10 & 12Jim; odontophore = 14 & 20 uttv; total stylet length = 24 & 32 pm; tail = 16 & 22 pm Brief description No crystalloids seen in cuticle. Lateral body pores distinct in one specimen, ventral and dorsal pores indistinct. Lateral chord 6-8 pm wide or 17-24 % of corresponding body width. Lip region 11-12 Jim wide, 6 Jim high. Amphid aperture 8 pm wide or 67-72 % of lip region width. Amphidial fovea stirrup-shaped, not duplex. Fusus with sensilla not visible. Guiding ring single, sclerotized, 7-8 Jim from anterior end. Nerve ring 83-96 Jim from anterior end. Hemizonid not observed. Basal bulb 42-46 Jim long, comprising 22-24 % of total neck length. Oesophageal gland nuclei indistinct, except dorsal gland nucleus in one specimen, situated at 87,9 % of total neck length. Cardia 15 Jim wide, 7 Jim long. Intestine four cells in circumference. Prerectum 345-445 Jim long or 43-44 % of total body length; intestine-prerectum junction 2,3-2,7 body widths anterior to vulva. Guard cells distinct at junction in one specimen (Figure 3C). Rectum 18-22 Jim long or 0,9 times the anal body diameter. No rectal glands could be seen. One pair of caudal papillae seen. Male and juvenile Not found. Locality and habitat Two females from soil among the roots of grasses under mopane trees (Colophospermum mopane) near the Savuti Marsh in the Chobe National Park, collected by A. Coomans and - 72 - J. Heyns 27 July 1989. Specimens On slide RAU 5203. Remarks Heyns (1963) based his description of this species on two females and a single male specimen from Bethal, Transvaal. He stated that L. transvaalensis differs from all known species in this genus in having the supplements close together, a duplex amphid, bluntly conoid tail and the intestine-prerectum junction slightly posterior to the vulva. In their key to Leptonchus species Goseco, Ferris & Ferris (1974a) used the short prerec tum to separate L. transvaalensis from other ieptonchus species, where the intestine prerectum junction is anterior to the vulva. They examined the type specimens of L. trans vaalensis but were unable to confirm or refute the position of the intestine-prerectum junction. Even so, they described the prerectum as 176-182 Jim long. The present author re-examined the type specimens and found the prerectum to be incon spicuous in both the holotype female and the paratype male. In the paratype female the prerectum could be seen, but the intestine-prerectum junction could not be determined with certainty, although there is an indication that it may be posterior to the vulva. Goseco & Ferris (1979) examined Nigerian specimens of L. transvaalensis and found the intestine-prerectum junction to be 2,5-4,0 body widths anterior to the vulva in the female (junction obscure in male specimens). - 73 - Tyleptus striatus Heyns, 1963 (Figure 3H-K) Measurements Females: (n = 2): L = 0,79 & 0,83 mm; a = 28,2 & 33,2; b = 4,4 & 4,3, c = 112,8 & 138; c' = 0,5; V = 33 & 30 %; odontostyle = 9,0 & 11,5 pm; odontophore = 9,0 & 9,5 pm; total sylet length = 18 & 21 pm; tail = 6,0 & 7,0 pm Brief description Exocuticle with fine transverse striations, endocuticle coarsely striated. Refractive ele ments or punctations seen over most of the body, radial elements, however, inconspic uous. Body pores indistinct. Lateral chord 10-11 pm wide or 39-40 % of corresponding body width. Lip region 5 pm wide, 4-5 pm high. Amphid aperture 5 pm wide; amphidial fovea stirrup-shaped. Odontostyle not very distinct; odontophore sclerotized. Guiding ring 4 pm from anterior end. Nerve ring inconspicuous. Hemizonid and hemizonion not seen. Oesophageal bulb pyriform. Cardia 7 pm long and 7 pm wide (n = 1). Individual intestinal cells indistinct. Prerectum inconspicuous. Rectum 13,5 pm long (n = 1). Tail very short, hemispheroid; caudal papillae indistinct. Reproductive system mono-opisthodelphic. Male and juvenile Not found. Locality and habitat Two female specimens from soil among the roots of herbaceous plants and palm trees on Boba Island (near Jedibe) in the Okavango Swamps, collected by A. Coomans and J. Heyns 31 July 1989. - 74- Specimens On slides RAU 5229 and 5230. Remark The female specimens from the Okavango agree well with the description of Tyleptus striatus by Heyns (1963) and by Goseco, Ferris & Ferris (1974b), except for a greater c ratio (112,8-138,0 vs 65-93 = combined measurements). ACKNOWLEDGEMENT Financial support by the Foundation for Research Development of the CSIR is gratefully acknowledged. REFERENCES BAJAJ, H.K. & BHATTI, D.S. 1980. Description of Proleptonchus shamimi n. sp. (Nemato da: Dorylaimida) with remarks on variability. Nematologica 26: 10-16. DE BRUIN, SANDRA & HEYNS, J. 1992. Dorylaimida (Nematoda) from Botswana. South African Journal of Zoology 27: 156-172. GOSECO, C.G., FERRIS, V.R. & FERRIS, J.M. 1974a. Revisions in Leptonchoidea (Nemato da: Dorylaimida). Leptonchus, Proleptonchus, Funaria, and Meylis n. gen. in Leptonchidae, Leptonchinae. Purdue University Agricultural Experimental Station Research Bulletin 911: 1-32. GOSECO, e.G., FERRIS, V.R. & FERRIS, J.M. 1974b. Revisions in Leptonchoidea (Nema toda: Dorylaimida). Tyleptus in Leptonchidae, Tyleptinae; Basirotyleptus in Lepton- - 75 - chidae, Belonenchinae; and Loncharionema n. gen. in Leptonchidae, Xiphinemelli nae. Purdue University Agricultural Experimental Station Research Bulletin 91 3: 1 24. GOSECO, C.G. & FERRIS, V.R. 1979. New data for teptonchus transvaalensis from Nigeria, and key to teptonchus. Journal ofNematology 11: 108-110. HEYNS, J. 1963. Five new species of teptonchidae (Nemata: Dorylaimoidea) from South Africa. Proceedings of the Helminthological Society of Washington 30: 7-15. JAIRAJPURI, M.S. 1964. Studies on the genus Proleotonchus Lordel/o, 1955 (Dorylaimoi dea: Leptonchidae) with description of two new species from India. Nematologica 10: 116-120. JAIRAJPURI, M.S. 1965. Qudsianema amabilis n. gen., n. sp. (Nematoda: Dorylaimoidea) from India. Proceedings of the Helminthological Society of Washington 32: 72-73. SIDDIQI, M.R. 1966. Studies on the Genera Calolaimus Timm, Galophinema Siddiqi, Qud sieneme Jairajpuri, and Utahnema Thorne (Nematoda: Leptonchidael. with descrip tion of U gracile n.sp. Proceedings of the Helminthological Society of Washington 33: 157-162. THORNE, G. 1961. Principles of Nematology. McGraw-Hili Book Co. 553 pp. (Accepted by Phytophylactica) - 76 - Figure 1: Eudorylaimus amabilis (Jairajpuri, 1965) Siddiqi, 1966 A. Neck region (first specimen) B. Anterior region (second specimen) C. Head region (first specimen) D. Reproductive system E. Heat-relaxed body postures F. Lateral chord G and H. Female tail regions - 77 - D F G lit lit o o 3 o 3 3 3 3 ~ m c "'T1 ?::t m o Figure 3: Leptonchus transvaalensis Heyns, 1963 A. Intestine-prerectum junction (first specimen) B. Oesophageal bulb and cardia C. Intestine-prerectum junction (second specimen) D. Shape and position of amphid E and F. Variation in female tail G. Heat-relaxed body posture Tyleptus striatus Heyns, 1963 H. Oesophageal bulb and cardia I. Female tail J. Head region K. Heat-relaxed body postures - 79 - A B c j LJ ,.)J 1 E· F I J .., I :t: .~. Ii' I « E E :l o VI o ... VI CHAPTER THREE Further records of dorylaim species from Botswana (Nematoda: Dorylaimida) ABSTRACT Seven known dorylaim species are recorded from Botswana. l1Iustrations and brief descrip- tions are given for Neoactinolaimus thornei Chaturvedi & Khera, 1979; Nygolaimus anneckei Heyns, 1968; Solididens vulgaris (Thorne, 1930) Thorne, 1974; Axodorylaimellus caffrae (Kruger, 1965) Jairajpuri & Ahmad, 1980; Dorylaimellus andrassyi Heyns, 1963; Dorylaimellus directus Heyns, 1963 and Tylencholaimus dorae Kruger, 1965. UITTREKSEL Verdere aanme/dings van dory/aim spesies vanaf Botswana (Nematoda: Dory/aimidaJ Sewe bekende dory/aim spesies word uit Botswana aangeme/d. lIIustrasies, asook kart beskrywings word gegee vir Neoactinolaimus thornei Chaturvedi & Khera, 1979; Nygolaimus anneckei Heyns, 1968; Solididens vulgaris (Thorne, 1930) Thorne, 1974; Axodorylaimellus caffrae (Kruger, 1965) Jairajpuri & Ahmad, 1980; Dorylaimellus andrassyi Heyns, 1963; Dorylaimellus directus Heyns, 1963 en Tylencholaimus dorae Kruger, 1965. INTRODUCTION This third report on Dorylaimida collected during a survey conducted in Botswana during July and August 1989, deals with seven known species, for which only brief descriptions - 80- are given based on the Botswana specimens, often supplementing or emending the exist ing descriptions in the literature. MATERIALS AND METHODS Specimens were extracted by a modified sieving-sedimentation method (Loubser, 1985), killed by gentle heat, fixed in FAA, processed into glycerine by Thorne's slow method and mounted on permanent slides. Measurements and drawings were made with the aid of a Zeiss Standard 18 research microscope equipped with a drawing tube. The body and all curved structures were measured along the median line. Oesophagus length (neck length) was measured from the anterior end of the body to the base of the oesophagus. Slide .numbers refer to the nematode collection of the Department of Zoology, Rand Afrikaans University. TAXONOMY Neoactinolaimus thornei Chaturvedi & Khera, 1979 (Figure 1) Two females and two males from the Chobe National Park are in agreement with the description of N. thornei by Chaturvedi & Khera (1979). In the Botswana specimens the odontophore is however much shorter (23 pm vs 42 pm in females; 23 pm & 25 pm in males). This discrepancy may be due to a difference in interpretation of the odontophore. It may well be that Chaturvedi & Khera (1979) measured the odontophore as if reaching to the base of the probulbus which then gives it a calculated length of 39 pm according to their Figure 18A. Considering that the odontophore normally reaches to more or less the middle.of the probulbus, the calculated length of the odontophore according to Figure 18A may be 21 or 26 pm, corresponding in this regard to the present specimens. The cuticle - 81 - in the Botswana specimens appears to be smooth and not finely striated, and in the female, the tail tip is curved ventrad vs straight. Measurements Females: (n = 2): L = 2,55 & 2,15 mm; a = 52,0 & 48,9; b = 4,9 & 4,8; c = 12,9 & 11,6; c' = 7,9 & 7,7; V = 44 & 41 %; odontostyle = 22 & 24 pm; odontophore = 23 & ? pm; total stylet length = 45 pm & ? pm; tail = 197 & 185 pm Males: (n = 2): L = 2,62 & 2,66 mm; a = 53,5 & 55,1; b = 4,9 & 4,0; c = 154 & 157; c' = 0,6; odontostyle = 22 & 21 pm; odontophore = 23 & 25 pm; total stylet length = 45 & 46 pm; spiculum = 50 & 52 pm; tail = 17 pm Brief description Female Lateral and ventral pores distinct, present over entire body, dorsal pores limited to neck region. Lip region 17-18 pm wide, 8 pm high (n = 1). Stoma as in original description. Guiding ring double, 16 pm from anterior end. Oesophagus 450-520 pm long. Endolid present in lumen of anterior part of oesophagus. Cardia 20-24 pm long, 10-13 pm wide. Nerve ring 133-142 pm from anterior end. Hemizonid not seen. Intestine four cells in circumference. Prerectum and rectum 136 pm and 30 pm long {n = 1~ respectively. Rectal glands could not be seen. Tail elongate-conoid tapering to a ventrally curved tip. Hyaline part 26-39 pm long, or cytoplasmic core comprising 79-87 % of tail length. Two pairs of caudal papillae present. Reproductive system as in original description. - 82- Male Description as for females with the following differences. Lateral, dorsal and ventral pores distinct in neck region, indistinct over rest of body, except lateral pores conspicuous in posterior region (Figure 1F). A row of about eight subventral pores occurs in the posterior region (Figure 1F), as well as two pairs of subventral papillae just anterior to adanal pair of supplements (Figure 1D). Amphid apertures at base of lip region (Figure 1C). Guiding ring 15-17 pm from anterior end. Oesophagus 530-560 pm long. Tail short, bluntly rounded, with six pairs of caudal papillae. Reproductive system diorchic; testes opposed and outstretched, with common spermo duct. No muscular ejaculatory duct present. Sperm cells ovoid, 8-9 pm long. Three pairs of ejaculatory glands seen in one specimen, but the course of their ducts could not be followed. Spicules arcuate. Lateral guiding pieces 14-16 pm long. Supplements papilloid, arranged in two fascicles, anterior fascicle with 7-8 and posterior fascicle with 6 contig uous supplements. No third fascicle could be seen in the present specimens. Coppulatory muscles reaching up to anteriormost fascicle. Juvenile (Second stage) (n = 1): L = 1,34 mm; a = 46,2; b = 4,2; c = 8,3; c' = 9,4; odon tostyle = 11 pm; odontophore = ?; replacement odontostyle = 16 pm; tail = 160 pm General morphology similar to adults. Locality and habitat From soil on the bank of the Chobe River near the Lamont Ruins, Chobe National Park, collected 26 July 1989. - 83 - Specimens Females on slides RAU 4852 and 4854; males on slides RAU 4853 and 4855; juvenile on slide RAU 4849. Nygolaimus anneckei Heyns, 1968 Syn. Nygolaimus (Nygolaimus) anneckei Heyns, 1968 (Figure 2A-D) N. anneckei was first described by Heyns (1968) from specimens collected at Aliwal North, Cape Province, South Africa, at Roodeplaat near Pretoria, South Africa, and at Halle, Germany. A single female from the Chobe National Park is in agreement with the type population of this species. Measurements Female (n = 1): L = 1,27 mm; a = 42,3; b = 3,7; c = 63,5; c' = 1,0; V = 46 %; mural tooth = 7 pm; tail = 20 pm Brief description Heat-relaxed body posture irregularly curved in the shape of a letter S (Figure 20). Cuticle appearing to be without transverse striations; subcuticle with faint punctations visible on parts of body. Body pores indistinct. Lateral chord 4 pm wide or 13 % of corresponding body width. Lip region rounded, 12 pm wide, 6 Jim high; labial papillae distinct. Amphids seen in dorso-ventral view; apertures at base of lip region (Figure 2A). Mural tooth deltoid, dorsal curvature not seen due to dorso-ventral view of head, 7 pm long. Stoma 32,8 Jim long. Nerve ring at 92 Jim from anterior end. Numerous ganglia present. Hemizonid not seen. Oesophagus widening at 39 % of neck length. Sheath surrounding basal bulb rather distinct. Width of body at base of oesophagus divided by lip region width 2,4. Cardia not - 84- visible. Intestine four cells in circumference. Prerectum 35 pm long or 1,9 times the anal body diameter. Rectum 21 pm long or 1,2 times the anal body diameter. Tail conoid, bluntly rounded. Caudal papillae inconspicuous. Reproductive system didelphic-amphidelphic. Anterior and posterior reproductive branches 77 pm and 86 pm long, respectively. Vulva a long transverse slit. Individual cells of uteri difficult to discern; no pars dilatata uteri or pars dilatata oviductus present. Sphincter muscle between uterus and oviduct not visible. Anterior and posterior ovaries 41 pm and 48 pm long. No eggs or sperm cells present. Juvenile (n = 1) (? Third stage): L = 0,66 mm; a = 24,4; b = 2,3; c = 38,8; c' = 1,1; tooth = 5 pm; replacement tooth = 6 pm; tail = 17 pm General morphology similar to adult. Male Not found. Locality and habitat Female and juvenile from soil among the roots of grasses and mopane trees near the Savuti Marsh in the Chobe National Park, collected 27 July 1989. Specimens Female on slide RAU 5202 and juvenile on slide RAU 5203. - 85 - Solididens* vulgaris (Thorne, 1930) Thorne, 1974 Syn. Nygolaimus (Solididens) vulgaris (Thorne, 1930) Heyns, 1968 Nygolaimus vulgaris Thorne, 1930 (Figure 2E-H) * Thorne (1974) inadvertedly used the generic name Solidens instead of Solididens Two females from the Okavango are in almost complete agreement with the measurements of topotypes from Utah, U.S.A., as well as with specimens from Venezuela, Mauritius and South Africa (see Table 6 in Heyns, 1968). The present specimens differ only in having a longer tail in one specimen (36 Jim vs 20-30 Jim) and a slightly narrower lateral chord. According to Heyns (1968), the body of S. vulgaris has a characteristic sideways twist after death, with the result that mounted specimens may assume the shape of either a letter S or a letter C. The Botswana specimens lie more in the shape of an incomplete figure 6 (Figure 2H). Measurements Females (n = 2): L = 1,11 & 1,29 mm; a = 34,7 & 43,0; c = 35,8 & 39,6; c' = 1,6 & 1,7; V = 54 & 55 %; tooth = 8 Jim; tail = 28 & 36 Jim Brief description Cuticle appearing smooth. Body pores inconspicuous, except for a few lateral pores in the neck region of one specimen. Lateral chord 4-5 Jim wide or 14-1 6 % of corresponding body width. Lip region in dorso-ventral view due to twisted condition of body, 11 Jim wide, 5 Jim high; labial papillae distinct. Amphid apertures at base of lip region. Mural tooth solididentoid, 8 Jim long, basal third hollow. Stoma 25-28 Jim long. Nerve ring at 101-102 Jim from anterior end; ganglia distinct. Hemizonid not seen. Oesophagus 410 420 Jim long, widening at 37-38 % of total neck length. Basal bulb 255-264 Jim long. - 86 - Sheath surrounding basal bulb conspicuous at base (Figure 2F). Width of body at base of oesophagus divided by lip region width 2,8-3,2. Cardia 8,0-11,5 pm long and 8,5-9,0 pm wide. Intestine four cells in circumference. Prerectum and rectum 25 pm and 19-21 pm long or 1,2-1,4 and 19-21 times the anal body diameter, respectively. Tail bluntly conoid, convex dorsad. Two pairs of caudal papillae seen. Reproductive system didelphic-amphidelphic. Anterior and posterior reproductive branches 64-90 pm and 71-105 pm long, respectively. Vulva a transverse slit; lips unsclerotized. No distinct pars dilatata uteri or pars dilalata oviductus could be seen. Sphincter muscle discernible. Anterior and posterior ovaries 36-53 pm and 44-49 pm long, respectively. No sperm cells or eggs present. Male and juvenile Not found. Locality and habitat From soil under herbaceous plants and palm trees on Boba Island (near Jedibe) in the Okavango Swamps, collected 31 July 1989. Specimens On slides RAU 5219 and 5225. Axodorylaimellus caffrae (Kruger, 1965) Jairajpuri & Ahmad, 1980 Syn: Dorylaimellus caffrae Kruger, 1965 (Figure 21-L) Female specimens from the Okavango agree with the original description of A. caffrae by Kruger (1965) as well as with measurements given by Jordaan & Heyns (1984). - 87 - Measurements Females (n = 4): L = 0,50 (0,47-0,54) mm; a = 30,0 (27,6-31,8); b = 2,6 (2,5-2,8); c = 32,5 (29,4-35,3); c' = 1,4 (1,3-1,5); V = 58 (55-62) %; odontostyle = 5,5 (5,O-6,O) pm; odontophore = 9,8 (9,O-10,0) pm; total stylet length = 15,3 (15,O-16,O) pm; tail = 15,5 (15,O-16,O) pm Brief description Lateral chord 5,3 (5,O-6,O) pm wide or 31 (29-35) % of corresponding body width. Glandular organs obscure. Lip region 6 pm wide, 2,8 (2,5-3,O) pm high. Amphids indistinct. Stylet aperture one third the odontostyle length. Guiding ring single, unsclerotized, 3,5 pm from anterior end. Nerve ring distinct in two specimens, 52,5 and 56,0 pm from anterior end. Hemizonid and hemizonion not seen. Oesophagus 193 (170 210) pm long. Anterior slender part of oesophagus less muscular than posterior expanded bulb, which is surrounded by a thick muscular sheath. Basal bulb 98 (89-103) pm long, or comprising 51 (42-59) % of total neck length. Oesophageal gland nuclei indistinct, except for the dorsal gland nucleus, situated at 50-53 % (n = 3) of total neck length. Cardia 5 pm wide, 4,8 (4,O-6,O) pm long. Prerectum 45 (37-46) pm long or 3,78 (3,7-3,8) times the anal body diameter. Rectum 11 (10-13) pm long or 1,02 (O,8-1,2) times the anal body diameter. Caudal papillae indistinct. Reproductive system didelphic-amphidelphic and not clearly defined. Vulva a transverse slit with unsclerotized lips. Anterior and posterior ovaries of unequal length viz. 12,0-48,5 pm (n = 3) and 17-40 pm (n = 3), respectively. Eggs and sperm cells absent. Male and juvenile Not found. - 88- Locality and habitat Specimens collected from wet soil among the roots of a sausage tree (Kigelia africana) standing on the edge of the water on Boba Island, Okavango Swamps, 1 August 1989. Specimens On slide RAU 5279. Remarks In his diagnosis Kruger (1965) compared A. caffrae with Axodorylaimellus parvulus (Thorne, 1939) Jairajpuri & Ahmad, 1980. According to him A. caffrae differs from A. parvulus by a much shorter prerectum and in having fewer lateral gland organs (11 vs 15). In their report on several more specimens of A. caffrae, Jordaan & Heyns (1984) made no reference to the glandular organs and in the Botswana specimens these are unfortunately indistinct. In the original description of A. caffrae, the prerectum length is reported as slightly more than two times the body diameter. Considering the a-ratio, the calculated prerectum length would be 37 pm or 2,8 anal body widths which corresponds to the perectum length of 37-46 pm or 3,7-3,8 anal body widths in the Botswana specimens and three anal body widths in Jordaan & Heyns's specimens. According to the original descrip tion of A. parvulus the prerectum is five body widths long, which seems to be incorrect, since body width is 21,2 pm (according to the formula) and the prerectum thus 106 pm long. The calculated prerectum length from Thorne's (1939) Figure 184A is however 64 pm or three anal body widths, which corresponds to that of A. caffrae. Prerectum length, thus does not seem to be a distinguishing character between A. caffrae and A. pervulus. The only reliable character left is the more strongly offset lip region of A. caffrae. Apart from Axodorylaimellus crassidens Siddiqi, 1983 and A. iari Siddiqi, 1983 with which Jordaan & Heyns further compared A. caffrae, it is also very similar to A. aghai Siddiqi, 1983 regarding the distinctly striated cuticle, indistinct glandular bodies and poorly deve loped uteri. It differs from this species only in the cylindrical tail vs subcylindrical in A. - 89- aghai. Dorylaimellus directus Heyns, 1963 (Figure 2M-P) A single female from the Okavango agrees with the type description of D. directus by Heyns (1963) as well as with the figures given by Jordaan & Heyns (1984) and with the measurements by Heyns & Jordaan (1985). Measurements Female: (n = 1): L = 0,75 mm; a = 30; b = 2,8; c = 21,4; c' = 2,3; V = 50 %; lip region width = 8 JIm; lip region height = 2 JIm; odontostyle = 9 JIm; odontophore = 15 JIm; total stylet length = 24 JIm; tail = 36 JIm Brief description Lateral chord 4 JIm wide or 34 % of corresponding body width. Glandular organs which are obscure in the type specimens (Heyns, 1963), can be seen quite distinctly in the present specimen. Lip region 8 JIm wide, 2 JIm high. Nerve ring 66 JIm from anterior end. Oesophagus 259 JIm long; basal bulb 169 JIm long, comprising 65 % of total neck length. Dorsal gland nucleus located at 67,4 % of total neck length, outlet indistinct. Subventral gland nuclei and their outlets inconspicuous. Cardia 8 JIm long, 6,5 JIm wide. Individual intestinal cells obscure. Junction between prerectum and intestine indistinct. Rectum 26 JIm long or 1,6 times the anal body diameter. Tail elongate conoid; caudal papillae inconspicuous. Reproductive system didelphic-amphidelphic. Uteri weakly developed. No sperm cells or eggs present. - 90- Male and juvenile Not found. Locality and habitat From soil around the roots of grasses under an Acacia tree at Serondella, close to the Chobe River in the Chobe National Park, collected 26 July 1989. Specimen On slide RAU 5145. Remarks D. directus, Dorylaimellus montenegricus Andrassy, 1959 and Dorylaimellus monticolus Clark, 1963 are three closely related species. According to Heyns & Jordaan (1985), D. montenegricus can be distinguished from the other two species by the relatively shorter basal bulb (basal bulb percentage is 43-52 % for D. montenegricus vs 50,7-64,0 % for both D. directus and D. monticolus) , whilst D. directus can be distinguished from D. monticolus by greater odontostyle, odontophore and total stylet lengths. Dorylaimellus andrassyi Heyns, 1963 (Figure 3) This is the most common dorylaimellid found in southern Africa. Heyns (1963) based the description of this species on 14 females and four males from several localities in the Transvaal, as well as from Clocolan in the Orange Free State, South Africa. Jordaan & Heyns (1984) subsequently reported some 165 females and 11 males from various locali ties in southern Africa. According to them this is an extremely variable species. - 91 - A single female from the Okavango and three males from the Chobe National Park are in agreement with the description of D. andrassyi by Heyns (1963) as well as with the de scriptions by Chaturvedi & Khera (1979) and by Jordaan & Heyns (1984). Heyns stated that the lateral guiding pieces are clearly visible in the type specimens, whilst Chaturvedi & Khera reported them to be obscure. According to Jordaan & Heyns the lateral guiding pieces are absent. In the Botswana specimens they are distinct in one specimen, but obscure in the other two specimens. Measurements Female (n = 1): L = 1,64 mm; a = 51,3; b= 9,1; c = 32,8; c' = 2,3; V = 49 %; odontostyle = 9 pm; odontophore = 12 pm; total stylet length = 21 pm; tail = 50 pm Males (n = 3): L = 1,60 (1,55-1,61) mm; a = 57,1 (51,7-60,0); b = 8,9 (8,8-9,1); c = 37,9 (35,0-39,7); c' = 1,77 (1,7-1,9); odontostyle = 6 (5-8) pm; odontophore = 9 (11 13) pm; total stylet length = 18,3 (18,0-19,0) pm; tail = 43 (39-46) pm Brief description Female Lateral chord 11 pm wide or 34 % of corresponding body width. Lip region 9 pm wide, 4 pm high. Amphid apertures at base of lip region (Figure 3B). Nerve ring 79 pm from ante rior end. Oesophagus 180 pm long; basal bulb 71 pm long or comprising 39 % of total neck length. Dorsal gland nucleus at 71 % of total neck length, outlet indistinct. Subven tral gland nuclei not visible. Cardia 10 pm long, 8,5 pm wide. Intestine four cells in circum ference. Junction between prerectum and intestine indistinct. Rectum 27 pm long or 1,2 times the anal body diameter. Tail conoid, convex dorsad; caudal papillae inconspicuous. Reproductive system didelphic-amphidelphic. Anterior and posterior branches 115 pm and 109 Jim long, respectively. Sphincter muscle between pars dilatata oviductus and pars - 92 - dilatata uteri distinct. No eggs or sperm cells present. Male Description as for females, but with the following differences. Lateral chord 8 (6-9) pm wide or 28 (22-32) % of corresponding body width. Nerve ring 68 pm (n = 2) from anterior end. Oesophagus 180 (170-190) pm long; basal bulb 70 (63-73) pm long or comprising 28 (22-32) % of total neck length. Dorsal gland nucleus visible in only one specimen, situated at 71,3 % of total neck length. Cardia 11,7 (11,0-12,0) pm long, 7,7 pm wide. Prerectum 136 pm long (n = 1). Reproductive system diorchic; testes opposed and outstretched. Sperm cells ovoid, 5 pm long. No ejaculatory glands seen. Spicules 37,7 (3,07-38,0) pm long. Supplements papilloid, 3-5 in number, arranged as shown in Figure 3G, I and J. Coppulatory muscles reaching up to anteriormost supplement. Juvenile Not found. Locality and habitat Female from wet soil among the roots of a sausage tree (Kigelia africana) standing on the edge of the water on Soba Island, Okavango Swamps. Males from soil around the roots of grasses under an Acacia tree at Serondella, close to the Chobe River in the Chobe National Park. Specimens collected 1 August and 26 July, respectively. Specimens Female on slide RAU 5281 and males on slide RAU 5146. - 93- Tylencholaimus dorae Kruger, 1965 (Figure 4) Females from the Chobe National Park correspond well to the description of T. dorae by Kruger (1965), except for a somewhat shorter and stouter body. Measurements Females (n = 2): L = 0,68 & 0,70 mm; a = 21,9 & 17,9; b = 3,8; c = 30,9 & 38,8; c' = 1,04 & 0,94; V = 66 & 71 %; odontostyle = 5,5 & 6,5 uttv; odontophore = 10,5 & 7,5 pm; total stylet length = 13 & 17 pm; tail = 22 & 18 pm Brief description Transverse striations on cuticle not conspicuous, except at the neck region in one speci men. Subcuticle striated, though sometimes irregularly separated from rest of cuticle. Radial elements visible towards the neck and tail regions, appearing as punctations when seen en face. Crystalloids present at tail region in one specimen. Lateral chord 8 pm wide or 21 % (n = 1) of corresponding body width. No body pores could be seen. Lip region 8,5-10,0 pm wide, 4-5 Jim high. Guiding ring single, sclerotized, 4-4,5 pm from anterior end. Oesophagus 180 pm long; basal bulb 77-81 pm long, comprising 43-45 % of total neck length. Cardia 7-12 Jim long, 9 pm wide. Nerve ring at 75-77 pm from anterior end. Hemizonid conspicuous in one specimen, opposite nerve ring. In the original description, Kruger (1965) mentioned nothing about the oesophageal glands and did not show it in his Figure. In the present material, the dorsal gland nucleus was clearly visible in both specimens, but nothing could be seen of the subventral nuclei, except in the one specimen where the the posterior pair was quite conspicuous (Figure 4A). The position of the nuclei and their outlets are as follows: DO = 66,6 % (n = 1); ON = 65,4 and 63,9 %; ~01 = 90,3 %; ~2 = 93,1 %; ~~ = 90,6 %; ~N2 = 91,9 %. Intestine four cells in circum ference. Prerectum and rectum 106 pm and 23 pm long or 2,6 and 0,6 (n = 1) times the - 94- anal body diameter, respectively. Caudal papillae could not be seen. Reproductive system monodelphic-prodelphic. Reproductive branch 87 pm long; uterus 52 pm long. No pars dilatata uterus or sphincter muscle could be seen. Sperm cells and eggs absent. Male and juvenile Not found. Locality and habitat One specimen from soil among grasses under a solitary palm tree in the north-western part of the Savuti Marsh, and a second specimen from soil among grasses under mopane shrubs near the Savuti Marsh, both collected in the Chobe National Park on 27 July 1989. Specimens On slides RAU 5177 and 5190. ACKNOWLEDGEMENTS The author wishes to thank the Foundation for Research Development of the CSIR for financial support, and Dr. P.A.A. Loof for valuable comments on the manuscript. - 95 - REFERENCES CHATURVEDI, Y. & KHERA, S. 1979. Studies on Taxonomy, Biology and Ecology of Nematodes associated with Jute Crop. Technical Monograph, Zoological Survey of India 2: 1-105. HEYNS, J. 1963. Notes on the genus Dorylaimellus Cobb, 1913 (Nemata: Dorylaimoidea), with descriptions of four new species. Nematologica 9: 391-404. HEYNS, J. 1968. A monographic study of the Nematode families Nygolaimidae and Nygo laimellidae. Entomology· Memoir, Department of Agricultural and Technical Services, Republic of South Africa 19: 1-134. HEYNS, J. & JORDAAN, ROSEMARIE 1985. On the identity of Dorylaimellus montenegri cus Andrassy, 1959, D. monticolus Clark, 1963 and D. directus Heyns, 1963 (Nematoda: Belondiroidea). Phytophylactica 17: 1-3. JORDAAN, ROSEMARIE & HEYNS, J. 1984. Sout~ern African species of the subfamily Dorylaimellinae (Nematoda: Dorylaimida). Phytophylactica 6: 283-300. KRUGER, S.P. 1965. New species of the genera Tylencholaimus and Dorylaimellus from South Africa. Proceedings of the Helminthological Society of Washington 32: 1-7. LOUBSER, T. J. 1985. A modified sieving-sedimentation method for extracting nematodes from soil. Horticultural Science 3: 23-25. THORNE, G. 1939. A monograph of the nematodes of the superfamily Dorylaimoidea. - 96 - Capita Zoologica 8: 1-261. THORNE, G. 1974. Nematodes of the Northern Great Plains. Part II. Dorylaimoidea in part (Nemata: Adenophorea). Technical Bulletin of the Agricultural Experimental Station South Dakota State University. Brookings South Dakota 41: 1-120. (Accepted by the South African Journal ofZoology) - 97 - Figure 1: Neoactinolaimus thornei Chaturvedi & Khera,1979 A. Neck region (female) Band C. Head in lateral and dorso-ventral view D. Tail region of male E. Posterior region of female F. Posterior region of male G. Heat-relaxed body postures of males H. Heat-relaxed body postures of females I. En face view of vulva J. Sperm cells K. Lateral guiding piece L. Anterior fascicle of ventromedian supplements - 98- A D E F G H , 2 S fJ m .s.c , 5 O fl m ,D,I,J ,SOllm , A,E,F • m I 2S 11 I K,L .1 mm ,G,H K V L Figure 2: Nygolaimus anneckei Heyns, 1968 A. Dorso-ventral view of head B. Oesophago-intestinal junction C. Posterior region D. Heat-relaxed body posture Solididens vulgaris (Thorne, 1930) Thorne, 1974 E. Dorso-ventral view of head F. Oesophago-intestinal junction G. Posterior region H. Heat-relaxed body postures Axodorylaimellus caffrae (Kruger, 1965) Jairajpuri & Ahmad, 1980 I. Neck region J. Head region K. Tail region L. Heat-relaxed body postures Dorylaimellus directus Heyns, 1963 M. Neck region N. Dorso-ventral view of head region O. Heat-relaxed body posture P. Tail region - 99 - I J M N G K o .H o p CG • 50 11m 1M ,12,511m , 2 5Ilm _ ,SOD pm -I A,E.J.N.K.P ,1mm • B,C. F,G ,1 mm .0' L ___- "D,H Figure 3: Dorylaimellus andrassyi Heyns, 1963 A. Neck region of female B. Dorso-ventral view of head region of male C. Female tail region D. Vulva and vagina region E. Heat-relaxed body posture of female F. Heat-relaxed body postures of males G. Posterior region of male H. Lateral chord with gland-like organs I and J. Variation in position of male supplements - 100 - c E· 6 - 'e ,0 lmm E,F I J \. " " Figure 4: Tylencholaimus dorae Kruger, 1965 A. Neck region B. Reproductive system C. Posterior region D. Head region E. Oesophago-intestinal junction F. Heat-relaxed body postures - 101 - A B E .25pm D,E , 2 5 11 m ,25pm 1500 11m t \ CHAPTER FOUR Cephalobidae {Nematoda: Rhabditidal from Botswana ABSTRACT Five Cephalobidae species are reported from Botswana. Measurements, descriptions and illustrations are given for Seleborca mariannae (Andrassy, 1968), S. complexa (Thorne, 1925), Acrobeles singulus Heyns, 1969 and Zeldia punctata (Thorne, 1925). Zeldia species cf punctete is described, but not named. A note on S. recurva (Heyns, 1969) from Namibia and South Africa is also given. UITTREKSEL Cephalobidae (Nematoda: Rhabditida) vanaf Botswana Vyf Cephalobidae spesies word uit Botswana aangemeld. Afmetings, beskrywings en illustrasies word gegee vir Seleborca mariannae (Andrassy, 1968), S. complexa (Thorne, 1925), Acrobeles singulus Hevns, 1969 en Zeldia punctata (Thorne, 1925). 'n Zeldia spesie verwant aan Z. punctata word beskryf maar nie benaam nie. 'n Nota oar S. recurva IHevns, 1969) in Namibie en Suid-Afrika word oak gegee. INTRODUCTION This is a further report on the terrestrial nematodes obtained during a survey in Botswana by A. Coomans and J. Heyns during July and August 1989. The present paper reports only on. Cephalobidae. - 102 - MATERIALS AND METHODS Specimens were killed in water by gradual application of heat, fixed in FAA, processed into glycerine according to Thorne's (1961) slow method and mounted on permanent slides. Measurements and drawings were done with the aid of a Zeiss Standard 18 research microscope, equipped with a drawing tube. The body and all curved structures were measured along the median line. Oesophagus length (neck length), position of excretory pore and nerve ring, exclude the labial probolae. Identification of juvenile stages was done on the basis of the number of cells in, and developmental stage of the genital primordia, USiAg Chitwood & Chitwood (1974) as a guideline. All measurements are in pm unless stated otherwise. Slide numbers refer to the nematode collection of the Department of Zoology, Rand Afrikaans University. TAXONOMY Seleborca mariannae (Andrassy, 1968) Andrassy, 1985 (Figure 1; Table 1) s. mariannae was first described by Andrassy (1968) from specimens collected in Para guay. Further records were i.a. from South Africa (Heyns, 1969), Brazil (Rashid, Geraert & Sharma, 1984), the Krakatau Islands (Rashid, Geraert, Sharma & Suatmadji, 1988) and Namibia (Rashid, Heyns & Coomans, 1990). Female specimens from Chobe National Park, Moremi Wildlife Reserve and the Okavango, correspond well to the above mentioned descriptions. Description Female. (n = 13) Body of heat-relaxed specimens ranging from straight to curved ventrad. Annuli 1,5-3,0 - 103 - pm wide. Lateral field 17 (1 5-17) % of corresponding body width, with four lines (Figure 1 G)' Head region with probolae similar to the descriptions by Rashid et el. (1984) and Rashid et al. (1990). Amphid apertures rounded, situated on lateral cephalic probolae. Stoma 11 (7-12) pm long; individual rhabdia clearly demarcated in most specimens. Tooth on dorsal metarhabdion seen in only one specimen. Oesophagus with cylindrical corpus, the lumen appearing wide in eleven specimens, narrow in two. Isthmus short. Basal bulb ovoid, 24 (21-25) pm long, 19 (17-20) pm wide. Two oesophageal gland nuclei visible (Figure 1A and F). Cardia hemispheroid, 5,4 (4,0-6,0) pm long. Excretory pore distinct, renette cell conspicuous, on ventral side of body just anterior to basal bulb or slightly to moderately anterior (Figure 1A and E). Hemizonid and deirid not observed. Nerve ring encircling base of corpus. Numerous nerve ganglia present. Intestine seemingly with four cells in circumference, intestinal cell nuclei large. Rectum 19 (15-24) pm long or 1,3 (1,1-1,5) times the anal body with. Tail elongate-conoid, somewhat constricted at about two-thirds of its length. Tail terminus acute. Phasmid at 36 (30-43) % (n = 7) of tail length or 9 (7 10) annuli from anus. Nerve ganglia abundant in tail region. Tail of one female aberrant, arcuate ventrad with recurved terminus (Figure 1E). Reproductive system cephaloboid. Vulva a transverse slit; lips slightly raised. Vagina 34 (21-43) % of corresponding body width. Postvulval uterine sac 16 (5-28) pm or 0,7 (0,2 1,0) body widths long. Uterus 57 (42-63) pm long; individual cells not clearly demarcated. Spermatheca short and empty, indistinct in four specimens. Oviduct short with three to four pairs of cells. Ovary distinct, reflexed at oviduct, 86 (66-114) pm long. Oocvtes in single row. No eggs or sperm cells present. Male Not found. - 104 - Juveniles (First stage) (n = 1) from Moremi Wildlife Reserve: L = 0,37 mm; a = 19,5; b = 3,3; c = 8,8; c' = 3,8; tail = 42 pm (Third stage) (n = 1) from Chobe National Park: L = 0,43 mm; a = 17,2; b = 3,6; c = 12,3; c' = 2,7; tail = 35 pm (Third stage) (n = 1) from Moremi Wildlife Reserve: L = 0,39 mm; a = 22,9; b = 3,5; c = 9,6; c' = 4,4; tail = 40 pm General morphology similar to adults. Genital primordia distinct. Locality and habitat Chobe National Park: Adults from soil among the roots of grasses under an Acacia tree at Serondella, close to the Chobe River and from soil among the roots of grasses under a solitary palm tree (Hyphaene benguellensis) in the northwestern part of the Savuti Marsh; juvenile from soil among the roots of grasses under mopane trees near the Savuti Marsh. Moremi Wildlife Reserve: adults and juvenile from soil among the roots of grasses on the northern side of the Kwai River Delta. Okavango: from soil among the roots of herbac eous plants and palm trees on Soba Island (near Jedibe). Samples collected 27, 28 and 31 July 1989, respectively. Specimens Females on slides RAU 4858,4863, 4864, 4868, 4872, 5145, 5164, 5200 and 5230, juveniles on slides RAU 4863 and 5189. - 105 - Seleborca complexa (Thorne, 1925) Andrassy, 1985 (Figure 2; Table 1) The first report of S. complexa from southern Africa was by Heyns (1969) who reported this species as widespread and common in South Africa. The only other report from southern Africa was by Rashid et al. (1990) from Namibia. Female and male specimens from Chobe National Park and Moremi Wildlife Reserve correspond well to the above mentioned descriptions, and with the very detailed report on the morphology of S. com plexa by Thomas (1965). Description Female (n = 7) Body of heat-relaxed specimens ranging from almost straight to moderately curved ventrad. Annuli 2 pm wide. Lateral field with four lines (Figure 2J), 15 (11-19) % of corresponding body width, inconspicuous in neck region. Head region as described by Rashid et al. (1990). Amphid apertures rounded. Stoma 11,3 (9,5-13,0) pm long, individual rhabdia clearly demarcated in some specimens. Tooth not seen on dorsal metarhabdion. Corpus fusiform; lumen appearing narrow. Corpus separa ted from short isthmus by transverse markings (the transition zone of Thomas, 1965) (Figure 2G). A distinct outlet visible just anterior to this zone in some specimens. Basal bulb ovoid, 30 (27-33) pm long, 22 (20-23) pm wide. Two oesophageal gland nuclei visible in most specimens. Cardia hemispheroid, 4,6 (4,0-5,0) pm long. Excretory pore opposite middle of isthmus, 124 (112-134) pm from anterior end of stoma. Renette cell situated anterio-ventral of basal bulb. Hemizonid and deirid not observed. Nerve ring encircling base of corpus; numerous nerve ganglia present. Intestinal cells with rather large nuclei. Rectum 20 (12-25) pm or 0,9 (0,5-1,3) anal body widths long. Tail elongate conoid, slightly curved ventrad, tail terminus acute. Phasmid at 25 (21-27) % of tail length - 106 - or 9,2 (8,0-10,0) annuli from anus. Nerve ganglia abundant in tail region. Reproductive system cephaloboid. Vulva a transverse slit. Vagina 9 (6-10) pm long or comprising 25 (20-29) % of corresponding body width. Uterus 72 (64-81) pm long. Spermatheca variable in size, with or without sperm cells. Oviduct short with about four pairs of cells. Ovary reflexed at oviduct, 210 (188-220) pm long. Oocvtes in single row. Postvulval uterine branch variable in length, 76 (41-11) pm or 2,3 (1,2-3,3) body widths long. No eggs or sperm cells present in uterus. Male (n = 11) Similar to female in general appearance, except body of heat-relaxed specimens ranging from slightly to strongly curved ventrad assuming the shape of a letter C. Reproductive system and male secondary structures as described by Thomas (1965) and by Rashid et st. (1990). Tail short, curved ventrad with acute terminus. Phasmid at 31 (25-37) % of tail length or 10,5 (8-12) annuli from anus. Numerous nerve ganglia present in tail region. Number and position of genital papillae in full agreement with other descrip tions of this species. Juveniles (Second stage) (n = 2): L = 0,39 & 0,43 mm; a = 0,2 & 21,3; b = 3,5 & 3,2; c = 10,7 & 8,9; c' = 3,0 & 3,4; tail 36 & 48 pm (Third stage) (n = 5): L = 0,55 (O,50-0,58) mm; a = 19,5 (17,0-23,8); b = 3,8 (3,5 4,0); c = 9,4 (8,8-10,0); c' = 3,1 (2,6-3,8); tail = 58,2 (52-65) pm General. morphology similar to adults. Genital primordia distinct. - 107 - Locality and habitat Specimens from soil among the roots of grasses under mopane shrubs near the Savuti Marsh in Chobe National Park and from soil among the roots of grasses on the northern side of the Kwai River Delta on the northern border of the Moremi Wildlife Reserve, collec ted 27 and 28 July 1989, respectively. Specimens Adults on slides RAU 4859-4862, 4867, 4871, 4873,5188, 5190, 5191 and 5201, juveniles on slides RAU 4856, 4864, 4869, 5189 and 5190. Acrobeles singulus Heyns, 1969 (Figure 3) The original description of this species was based on specimens collected at various locali ties in South Africa. Sauer & Annells (1984) gave a short description of Australian specimens with SEM photographs of the head region. Other populations described were La. from Brazil (Rashid, et al., 1984) and from the Krakatau Islands (Rashid et al., 1988). Females from the Chobe National Park are in agreement with the above mentioned descrip tions, except for a slightly more anteriorly situated vulva viz. 55-62 % vs 60-63,5 %. Measurements Female (n = 6): L = 0,39 (0,35-0,43) mm; a = 17,8 (16,1-19,5); b = 3,6 (3,3-3,9); c = 7,9 (7,2-8,7); c' = 4,1 (3,5-4,8); V = 57 (55-62) %; tail = 49 (42-53) pm Description Body of heat-relaxed specimens ranging from straight to moderately curved ventrad. Annuli 2-3 pm wide, total number of body annuli varies from 170 to 177 of which 43 to - 108 - 55 occur from head to base of oesophagus, 52 to 56 from base of oesophagus to vulva, 48 to 52 between vulva and anus and 17 to 22 on the tail. Lateral field 13,7 (13-14) % of corresponding body width, with two lines, the area between the lines stippled (Figure 3G). Probolae as described by Heyns (1969), Rashid et at. (1984) and Rashid et at. (1990), except that the labial probolae are not distinctly curved inwards. Amphid apertures rounded. Stoma 8,8 (8,0-9,0) pm long, individual rhabdia clearly demarcated. Oesophagus with cylindrical corpus, lumen appearing wide, narrowing towards short isthmus. Basal bulb ovoid, 20 (19-22) pm long, 15 (14-17) pm wide. Two oesophageal gland nuclei visible in most of the specimens. Cardia hemispheroid, 4,3 (4,0-5,0) pm long. Excretory pore with duct very distinct, situated 17 to 24 annuli from the head; renette cell conspicuous on ventral side of body just anterior to basal bulb or slightly further forward. Hemizonid opposite nerve ring (Figure 3A). Deirid observed in only one specimen at the level of isthmus between the lateral lines (Figure 3B). Nerve ring encircling base of oesophagus 61 (53-67) pm (n = 4) from beginning of stoma. Nerve ganglia not in abundance. Intestine seemingly with four cells in circumference, intestinal cells with large nuclei. Rectum 14 (12-17) pm or 1,2 (1,0-1,7) times the anal body width long; rectal glands observed in some specimens. Tail elongate-conoid, terminus acute. Phasmid at 25 (24-28) % of tail length or about five annuli from anus (n = 3). Reproductive system cephaloboid. Vulva a transverse slit with unprotruding lips. Vagina 20 (19-26) % of corresponding body width. Postvulval uterine sac 12 (10-14) pm or 0,6 (0,5-0,7) body widths long. Uterus 39 (37-44) pm long, individual cells not always clearly demarcated. Oviduct short with three pairs of cells. Spermatheca visible in three speci mens, short and empty. Ovary reflexed at oviduct, 75 (57-96) pm long with oocvtes in a single row. No eggs or sperm cells present in uterus. - 109 - Male and juvenile Not found. Locality and habitat From soil among the roots of grasses under a solitary palm tree (Hyphaene benguellensis) in the northwestern part of the Savuti Marsh in the Chobe National Park, collected 27 July 1989. Specimens On slides RAU 5165 and 5166. Zeldia punctata (Thorne, 1925) Thorne, 1937 (Figure 4) Seven females and twelve juveniles from the Chobe National Park and the Okavango Swamps agree well with the redescription of Z. punctata by Allen & Noffsinger (1972) of specimens collected at the type locality viz. Indio, California. The Botswana specimens are also in agreement with other populations, i.a. from South Africa (Heyns, 1962), Brazil (Rashid, et el., 1984) and Namibia (Rashid & Heyns, 1990). The width of the cephalic axils are, however, slightly larger in the present specimens (3 pm vs 1,5-2,0 pm - mea surements according to Rashid & Heyns, 1990). Measurements Females (n = 7): L = 0,62 (0,57-0,69) mm; a = 24,6 (21,9-28,2); b = 3,4 (3,3- 3,6); c = 16,3 (12,6-18,6); c' = 2,5 (2,2-3,1); V = 66 (64-68) %; tail = 37 (33-47) pm Description Body of heat-relaxed specimens ranging from almost straight to slightly curved ventrad. - 110- Annules 2-3 pm wide. Punctations indistinct, except at tail region of some specimens. Lateral field 18 (8-21) % of corresponding body width, with three lines, outer lines crenate. Area between lines appearing punctate or stippled, a character also reported by Heyns (1982) and by Rashid et al. (1984). Margins of labial probolae slightly furcate. Cephalic probolae with simple margins, without small membranous projections. Cephalic axils 3 pm wide, dentate. Amphid apertures distinct in only one specimen, appearing almost rounded. Stoma 11 (10-13) pm long, rhabdia not always clearly demarcated. Cheilorhabdia without accessory teeth, dorsal metarhabdion with tooth. Oesophagus 181 (168-200) pm long, transverse markings separating corpus from isthmus sometimes seen. Basal bulb ovoid, 21 (23-27) pm long, 17 (15-20) pm wide. One or two oesophageal gland nuclei visible in most specimens. Cardia hemispheroid, 5,5 (5,0-6,5) pm long. Nerve ring encircling corpus 96 (85-108) pm from anterior end of prostom, numerous nerve ganglia present. Excretory pore distinct, opposite nerve ring, renette cell variable in position, on lateral side of body at beginning of basal bulb or more anterior (Figure 4G and H). Hemizonid not observed; deirid distinct (Figure 4A). Intestine with four cells in circumference, intestinal cell nuclei large. Rectum 19 (16-22) pm long or 1,2 (1,1-1,5) times the anal body width, rectal glands inconspicuous. Tail conoid, curved ventrad at about the middle of its length, terminus minutely rounded. Phasmid at 23 (19-27) % of tail length. Female reproductive system cephaloboid, poorly differentiated in some specimens. Vulva a transverse slit, lips slightly raised. Vagina occupying 28 (26-32) % (n = 4) of correspond ing body width. Postvulval uterine sac short. Individual cells of uterus not clearly demar cated, spermatheca present. Oviduct short, with three pairs of cells. Ovary reflexed at oviduct, 93 (77-11 O) pm long (n = 4). oocvtes in single row. No eggs or sperm cells present." - 111 - Male Not found. Juveniles (Third stage) (n = 12): L = 0,56 (0,47-0,64) mm; a = 24,1 (20,4-29,5); b = 3,5 (3,1 4,4); c = 14,4 (12,1-16,9); c' = 2,7 (2,2-3,2); tail = 38,5 (33-53) pm General morphology similar to adults. Genital primordia distinct. Locality and habitat Adults from soil among the roots of grasses under a solitary palm tree (Hyphaene benguel lensis) in the northwestern part of the Savuti Marsh, Chobe National Park and from soil under herbaceous plants and palm trees on Soba Island (near Jedibe) in the Okavango Swamps. Juveniles found only at the first mentioned locality. Specimens collected 27 and 31 July 1989. Specimens Females and juveniles on slides RAU 5164-5173, 5188, 5230 and 5231. Remarks Z. punctata is closely related to Zeldia minor Allen & Noffsinger, 1972, differing only in the width of the cephalic axils (more than 1,5 pm for Z. punctata and less than 1,0 pm for Z. minor). Rashid et al. (1984) considered Z. minor a possible junior synonym of Z. punctata, a viewpoint with which the author tends to agree. - 112 - Zeldia species cf punctata (Thorne, 1925) Thorne, 1937 (Figure 5) Loof (1964) reported Zeldia specimens, female and juvenile, from Venezuela with charac teristic long tails and with the tail end curved ventrad. The lip region was covered in dirt particles in all adult specimens, but could be clearly seen in three juveniles. Two females from Chobe National Park correspond well to the Venezuelan specimens especially as far as measurements and tail shape are concerned. The lip region in the Botswana specimens is also similar to the illustration of the juvenile lip region by Loof (1964) (his Figure 7A). Measurements Females (n = 2): L = 0,80 & 0,89 mm; a = 25,8 & 24,1; b = 4,0 & 4,2; c = 12,3 & 13,3; c' = 3,4 & 3,2; V = 63 & 60 %; tail = 65 & 67 pm Description Body of heat-relaxed specimens slightly curved ventrad. Annuli 2 pm wide. Punctations visible in subcuticle of one specimen, present over entire body, but more distinct in neck region, arranged in two rows per annule. Punctations indistinct in second specimen, except towards tail region. Lateral field distinct, 13 and 28 % of corresponding body width, with three incisures. Labial probolae somewhat furcate, cephalic probolae with simple margins, without small membranous projections. Cephalic axils 2,0 and 2,5 pm wide, dentate. Amphid aperture conspicuous in one specimen only, elongate-ovoid. Stoma 12,5 pm long, individual rhabdia clearly demarcated. Cheilorhabdia without accessory teeth, dorsal metarhabdion with tooth. Oesophagus 200 and 209 pm long, transverse markings separating corpus from isthmus. not observed. Basal bulb ovoid, 25 and 27 pm long, 19 and 20 pm wide. A single oesophageal gland nucleus visible in each specimen. Cardia hemispheroid, 2 pm - 113 - long. Nerve ring encircling corpus 120 and 130 pm from anterior end of prostom, numer ous nerve ganglia present. Excretory pore distinct, opposite nerve ring, renette cell incon spicuous. Hemizonid and deirid not observed. Intestine with four cells in circumference, intestinal cell nuclei large. Rectum 21 and 22 pm long or 1,1 and 1,0 times the anal body width, rectal glands inconspicuous. Tail elongate-conoid, slightly curved ventrad at about its middle. Tail end curved ventrad, more so in one specimen, tail terminus acute. Phasmid at 16 and 17 % of tail length. Reproductive system indistinct in both specimens. Vulva, however, visible, a small trans verse slit with lips slightly raised. Male and juvenile Not found. Locality and habitat Two females from soil among the roots of grasses under mopane shrubs near the Savuti Marsh, Chobe National Park, collected 27 July 1989. Specimens On slides RAU 5190 and 5201. Remarks These specimens come close to Zeldia punctata (Thorne, 1925), Thorne, 1937, especially regarding body length, lip region structure and general morphology, but differs from it in having a longer tail. Although Z. punctata also includes larger specimens (up to 0,94 mrn), the tails are always short (32-51 pm - measurements according to Rashid et al., 1984 and Rashid & Heyns, 1990). Discovery of further populations will have to be awaited to determine whether these specimens represent a variation of Z. punctata or possibly a new - 114 - species. Note on Seleborca recurva (Heyns, 1969) Andrassy, 1985 from Namibia and South Africa (Figure 2) Heyns (1969) described this species from Omarura, Namibia and from the Transvaal, South Africa. In the diagnosis he compared S. recurva with Acrobeles elaboratus Thorne, 1925 and with Seleborca ornata (Thorne, 1925) Andrassy, 1985, distinguishing it from both species by the absence of "rows of refractive dots" on the cuticle. Re-examination of the holotype and two paratypes revealed the presence of a single row of punctations on each annule as shown in Figure 2K. S. recurva can, however, still be distinguished from S. ornata by its shorter body (female: 0,63-0,65 mm vs 0,80-0,85 mm; male: 0,62- 0,66 mm vs 0,73 mrn), longer tail with subacute terminus vs shorter tail with acute terminus (c = 8,7 vs 17,0), more anterior vulva position (58 % vs 64 %) and only one row of puncta tions on each annule vs two rows in S. ornata. ACKNOWLEDGEMENT Financial support by the Foundation for Research Development of the CSIR is gratefully acknowledged. REFERENCES ALLEN, M.W. & NOFFSINGER, E.M. 1972. A review of the genus Zeldia Thorne, 1937 (Nematoda: Cephalobidae) with descriptions of seven new species. Proceedings of the Helminthological Society of Washington 39: 206-223. - 115 - ANDRaSSY, I. 1968. Fauna Paraguayensis. 2. Nematoden aus den Galeriewaldern des Acaray Flusses. Opuscule Zoologica. Budapest 8: 167-315. CHITWOOD, M.B & CHITWOOD, B.G. 1974. Introduction to Nematology. University Park Press. 334 pp. HEYNS, J. 1962. Osstella hamata n.gen. n.sp., Zeldia serrata n.sp. and Acrobeles singulus n.sp., three new nematodes from South Africa (Rhabditida: Cephalobidae). Nemato logica 8: 301-306. HEYNS, J. 1969. South African species of the genus Acrobeles Von Linstow, 1877 (Nematoda: Cephalobidae). Phytophylactica 1: 57-66. LOOF, P.A.A. 1964. Free-living and plant-parasitic Nematodes from Venezuela. Nemeto logica 10: 201-300. RASHID, FARZANA, GERAERT, E. & SHARMA, R.D. 1984. Morphology, taxonomy and morphometry of some Cephalobidae (Nematoda: Rhabditida) from Brazil, with descriptions of two new genera and four new species. Nematologica 30 251-299. RASHID, FARZANA, GERAERT, E., SHARMA, R.D. & SUATMADJI, W. 1988. Cephalobi dae from the Krakatau region (Nematoda: Rhabditida). Nematologica 34: 125-143. RASHID, FARZANA, HEYNS, J. & COOMANS, A. 1990. Species of Seleborca Andrassy, 1985 from South West Africa/Namibia (Nematoda: Cephalobidae). Phytophy/actica 22: 51-62. - 116 - RASHID, FARZANA & HEYNS, J. 1990. Description of Namibinema scaphovulva n.gen. n.sp, and Zeldia punctata (Thorne, 1925) from Namibia (Nematoda: Cephalobidae). Phytophylactica 22: 297-403. SAUER, M.R. & ANNELLS, C.M. 1984. Lip region structure in Acrobelinae (Nematoda: Cephalobidae). Nematologica 30: 140-150. THOMAS, P.R. 1965. Morphology of Acrobeles complexus Thorne cultivated on Agar. Nematologica 11: 383-394. THORNE, G. 1961. Principles of Nematology. McGraw-Hili Book Co. 553 pp. (Accepted by Phytophylactica) - 117 - TAIlI.B 1: ~c data of sele!:orl:a IIIIl"1IDlae (1aJrissy. 1968) !lD:lIaSsy. 1985 aa:1 selebort:a cmnlexa ('lmme. 1925) AoiI3ssy. 1985 S. mriannae ~~ Q10be Natiooal Park !otlremi. Okavango Olobe National Park !tlre:Ii. n SA' 7'# B'· :JH. 5&1' 5&3' 60d' L(om) o,52(0,48-0,57) 0.48(0,4&-0,49) 0,52 O,76<0.7~,78) 0,63(0,55-0,72) O,69(O,6/H),71) 0,65(0,62-0.69) a 21.1{18.5-24.8) 19.9(18.1-21.4) 20.8 22.5(20.8-23.6) 20.0(15,3-23.8) 23.6(20.3-28,4) 23,8(16.G-26.4) b 3,9(3.&-4,1) 3.7(3.5-3,8) 4,1 4,6(4.5-4,7) 3,9(3.2-4,3) 4,0(3.9-4.2) 4.0(3,8-4.2) c 11.7(11.0-12.4) 11,4(8,7-11.7) 10.8 9.7(9.3-10,3) 11.9(9.5-12.7) 9.6(9.G-9.9) U,7(l1,G-14.3) c' 3.0(2.G-3.6) 3.1(2.8-4.4) 3.7 3.4(3.0-3.7) 2,1(2.0-2,1) 3.4(3.0-4.0) 2.1(1.7-2.6) V% 61(60-62) 61.8(60-63) 61.5 57.7(57-58) - 58(57-59) - Neck length excluding labial probolae 136(128-142) lJO(12G-141) 128 164(163-167) 161(150-170) 175(l6G-182) 165(158-178) Tail length 45(41-S1) 77(74-a1) 72(68-76) Sl,J(4lo-S5) ...... 42(3G-S3) 48 53.4(50-58) ...... Total body amill. 22S(21G-239) 221{215-226) 223 268(208-312) 289(270-303) 285(278-290) 270(263-281) CO Annuli fron heed to excretory pore 12(8-15) 12(9-15) 13 55(52-58) 53(48-56) 51(50-S2) 53(;0..55) Annuli fran head to 1:ase of oesophagus 62(60-63) 63(~9) 58 71(70-73) 7:l( 68-i30) 68(6G-71) 70(67-73) Annuli fran base of oesophagus to vulva 76(72-a2) 76(7o-&J) 78 105(9G-114) - 102(99-106) - Annuli fran vulva to aous 68(64-75) 65(62-':;6) 65 91(88-96) - 89(85-93) - Annuli fran base of oesophagus to anus - - - 193(181-204) - 180(173-187) Annuli oa tail 19(18-20) -17(1G-19) 22 30(29-32) 23(21-29) 26(24-28) 21(19-23) Excretory pore % 13(11-20) 18(lG-22) 20 70(67-76) 69.5(67-73) 73(70-76) 72(69-75) Nerve ring fran beginning of stem 88(77-95) 85(80-90) 85 116(114-118) 109(102-118) 116(111-121) 112(101-124) Spiculum lEflgt.'1 - - - - 36(31-40) - :.lS.5(33-39) QWernaculumlength - - - - 17(14-20) - 19.2(18-21) Figure 1: Seleborca mariannae (Andrassy, 1968) Andrassy, 1985 A. Anterior region of female B. Head region C. Female tail D. Female reproductive system E. Aberrant female tail F. Basal bulb region showing position of renette cell G. Lateral field H. Heat-relaxed body postures - 119 - c o G H ,1rnrn~'------lIH ,SOfJrn ,~=.!....sOfJrn -l' AC-G Figure 2: Seleborca complexa (Thorne, 1925) Andrassy, 1985 A. Anterior region of male 8. Female tail C and D. Heat-relaxed body postures of females and males, respectively E. Female reproductive system F. Posterior region of male G. Basal bulb region showing position of renette cell, oesophageal gland nuclei and transverse markings H. Head region I. Sperm cells in testis of male J. Lateral field Seleborca recurva (Heyns, 1969) Andrassy, 1985 K. Cuticle in neck region showing punctations - 120- A B c ((( (lee K e 0 00 0 0 0 0 0 0 0 0 o 00 0 0 0 000 00 e 000000000 o 0 0 00 000 0 00 00 00 0°0000000000 o 0 0 0 000 0 000000°000 ,50pm ,501lm J ,25pm Figure 3: Acrobeles singulus Heyns, 1969 A. Neck region B. Basal bulb region showing position of deirid C and D. Female reproductive system E and F. Female tail region G. Lateral field H. Head region I. Heat-relaxed body postures - 121 - c D II {I {, ,I I It II I, I{ ," " II" 11 II I'I I' I'I II I II "I G .. -- --.-- :.... i:: .. ------..- ..- :.:.: ... _--- ~ ..--.... - .. 1··,------r',.: ------.. _--- ::: ~ _..-_ ... - E ----.... -- 1.1-- ':':'; !:1 ~:.------.._- ....-- ;: :..~ ... ~~~~~~~~~- \.:\.. ..._-:=-~:=--\~ ...:\ ~::: I (c ,25f!m~~------.H ,25\lm Figure 4: Zeldia punctata (Thorne, 1925) Thorne, 1937 A. Anterior region of female B. Head region C and D. Female tail region E. Female reproductive system F. Lateral field G and H. Basal bulb region showing position of renette cell I. Heat-relaxed body postures - 122 - c F H ~A25 m I ~B ~C-H, Figure 5: Zeldia species cf punctata (Thorne, 1925) Thorne, 1937 A. Anterior region of female Band C. Head region D. Vulva region E and F. Female tail region G. Lateral field H. Cuticle showing punctations I. Heat-relaxed body postures - 123 - A D G H t ...... d- e ••••••...... 0 •••...-:: . ······0·...... to...... 0...... • 0 •••• .·...... ••'"0000... .0 '0 ...... e • .... ··...... o ••••••••• ...... , J I ,1mm'-=-"':.:.:.:...... J.. ,50pm ,25pm ,17,5f1m CHAPTER FIVE , r . A report on species of the orders Araeolaimida, Enoplida, Rhabditida and Tylenchida (Nematoda) from Botswana ABSTRACT Eight species of the orders Araeolaimida, Enoplida, Rhabditida and Tylenchida are reported from Botswana. Measurements, and mostly also descriptions and illustrations are given for Chronogaster longicauda Heyns & Coomans, 1980, Neotobrilus diversipapillatus (Daday, 1905) Tsalolikhin, 1981, Panagrolaimus hygrophilus Bassen, 1940, Panagrolaimus species cf australis (Cobb, 1893) Sudhaus, 1976, Hemicycliophora species cf labiata Colbran, 1960, a Neotobrilus species, Rotylenchus capensis Van den Berg & Heyns, 1974 (mea- surements and a description only) and Scutellonema cavenessi Sher, 1963 (measurements only). UITTREKSEL 'n Aanmelding van spesies van die ordes Araeolaimida, Enoplida, Rhabditida en Tylenchida (Nematoda) vanaf Botswana Agt spesies van die ordes Araeo/aimida, Enop/ida, Rhabditida en Ty/enchida word uit Botswana eenqemeld. Afmetings, beskrywings en i//ustrasies word gegee vir Chronogaster longicauda Hevns & Coomans, 1980, Neotobrilus diversipapillatus (Daday, 1905) Tselolik- hin, 1981, Panagrolaimus hygrophilus Bassen, 1940 esook vir 'n Panagrolaimus spesie verwant aan P. australis, (Cobb, 1893) Sudhaus, 1976, 'n Hemicycliophora spesie verwant aan H. labiata Colbran, 1960 en 'n Neotobrilus spesie. Afmetings en 'n beskrywing word ook gegee vir - 124 - Rotylenchus capensis Van den Berg & Heyns, 1974, terwyl slegs afmetings oeaee word vir Scutel lonema cavenessi Sher, 1963. INTRODUCTION This final report on terrestrial nematodes obtained during a surveyin Botswana by A. Coomans and J. Heyns during Julyand August 1989,deals with eight species ofthe orders Araeolaimida, Enopli da, Rhabditida and Tylenchida. MATERIALS AND METHODS Specimens were killed in water by gradual application of heat, fixed in FAA, processed into glycer ine according to Thorne's (1961) slow method and mounted on permanent slides. Measurements and drawings were done with the aid of a Zeiss standard 18 research microscope, equipped with a drawing tube. The body and all curved structures were measured along the median line. Identifica tion of juvenile stages was done on the basis of the number of cells in, and developmental stage of genital primordia, using Chitwood & Chitwood (1974) as a guideline. Slide numbers refer to the nematode collection of the Department of Zoology, Rand Afrikaans University. TAXONOMY Chronogaster longicauda Heyns & Coo mans, 1980 (Figure 1) This species was first described from freshwater in the Transvaal, South Africa by Heyns & Coomans (1980). A single female from the Chobe National Park is in complete agreement with the type description. According to Heyns & Coomans (1980) Chronogaster species are found in a wide range of habitats but mostly in freshwater. Species reported from - 125 - terrestrial habitats are C. tenuis Loof & Jairajpuri, 1965, C. citri Khan & Nanjappa, 1973, C. indica Bajaj & Bhatti, 1979 and C. africana Heyns & Coomans, 1980. C. longicauda can now be added to the latter group, since the Botswana specimen was collected from soil among the roots of grasses under an Acacia tree close to the Chobe River. Measurements Female (n = 1): L = 1,14 mm; a = 54,3; b = 5,2; c = 5,0; c' = 17,6; V = 45 %; length of cephalic setae = 8 pm; width of annules at midbody = 2 pm; distance between radial tubules and base of stoma = 16,5 pm; length of postbulbar elongation = 22,5 pm; cardia = 7 pm; tail = 229 pm Description Heat-relaxed body posture curved ventrad, more strongly so in posterior part. Transverse striations distinct. Lip region rounded, 5 pm wide, 5 pm high. Amphid aperture on second annule behind lip region. Stoma sclerotized, 6 pm long, 2 pm wide. Nerve ring, excretory pore and hemizonid inconspicuous. Oesophagus 218 pm long; corpus cylindroid and slender. Basal bulb hemispheroid, 16 pm long, 14 pm wide, lumen as described by Heyns & Coomans (1980). Intestinal cells large, nuclei inconspicuous. Rectum 16 pm or 1,2 anal body widths long. Tail as in original description. Reproductive system monodelphic-prodelphic. Vulva a transverse slit, lips unprotruding. Vagina occupying 33 % of corresponding body width. Postvulval uterine branch indistinct. Ovary 100 pm long; no mature oocvtss observed. No eggs or sperm cells present. Male and juvenile Not found. - 126- Locality and habitat A single female from soil among the roots of grasses under an Acacia tree at Serondella, close to the Chobe River in the Chobe National Park, collected 26 July 1989. Specimen On slide RAU 4846. Neotobrilus diversipapillatus (Daday, 1905) Tsalolikhin, 1981 (Figure 2A-F) Specimens from the Chobe National Park are in agreement with previous descriptions of N. diversipapillatus, especially with those of Argo & Heyns (1973) and Joubert & Heyns (1979). Measurements Female (n = 1): L = 2,56 mm; a = 32,0; b = 5,8; c = 13,5; c' = 6,3; V = 44 %; long cephalic setae = 11 pm; short cephalic setae = 7 uttv; tail = 189 pm Description Heat-relaxed body posture almost straight. Cuticle with fine transverse striations. Somatic muscles very distinct. Lateral chord inconspicuous. Head width 38 pm. Teeth rather small, anterior tooth 25 pm from front end of body, posterior tooth 12 pm behind first. Oesophagus 440 pm long; surrounding muscle bands distinct, more so in posterior region. Oesophageal-intestinal glands well developed. Nerve ring 148 pm from anterior end. Fairly large cells (most probably coelomocytes) present laterally along body (Figure 28). Excre tory pore (reported by Swart & Heyns, 1988) could not be observed. Intestine four cells in circumference. Rectum indistinct. Tail narrowing to form a relatively long cylindrical part ending in a rounded terminus with a subterminal seta. Only a single caudal gland distinct; - 127- spinneret terminal. Reproductive system didelphic-amphidelphic. Anterior and posterior branches 420 and 480 Jim long, respectively. Vaginal muscles strongly developed. Uteri fairly short and stout, individual cells not clearly demarcated, but appearing ring-like. No pars dilatata uteri. Sphincter muscle between uterus and sac-like pars dilatata oviductus elongated, with ring like cells. Oviduct very short. Ovaries relatively long, anterior and posterior ovaries 280 and 275 Jim long, respectively. No eggs or sperm cells present. Juvenile (Third stage) (n = 2): L = 1,08 & 1,16 mm; a = 32,7 & 34,1; b = 3,9 & 4,6; c = 7,3 & 8,0; c' = 7,0 & 6,3; anterior tooth = 14 & 15 Jim from front end of body; posterior tooth 25 & 26 Jim from front end of body; tail = 147 & 145 Jim General morphology similar to adult. Genital primordia distinct. Male Not found. Locality and habitat One female and two juveniles from soil among the roots of grasses next to an Acacia tree at the Lamont ruins, Chobe National Park, collected 26 July 1989. Specimens Female on slide RAU 4854, juveniles on slides RAU 4849 and 4840. - 128 - Neotobrilus species (Figure 2G-L) A single female and two juveniles from the Chobe National Park most probably belong to the Neotobrilus longus group. Since male characters play an important role in the taxonomy of this group, it is not possible to make a definite identification. However, the Botswana specimen comes close to Neotobrilus longus americanus (leidy, 1852) Tsalolikhin, 1983 but has a slightly shorter tail and thus a larger c-ratio (12,1 vs 7,6-10,0 - measurements according to Tsalolikhin, 1983 and Tsalolikhin, 1985) and the long cephalic setae are longer (1 5 pm vs 6,4 & 10,7 pm - calculated from the original illustrations by Tsalolikhin, 1983 and Tsalolikhin, 1985). Measurements Female (n = 1): L = 1,76 mm; a = 29,8; b = 4,8; c = 12,1; c' = 4,9; V = 49 %; long cephalic setae = 15 pm; short cephalic setae 5 pm; tail = 146 pm Description Heat-relaxed body posture slightly curved ventrad. Cuticle with minute striations. lateral chord distinct, 13 pm wide or 22 % of corresponding body width. Head width 27 pm. Amphids inconspicuous. Stoma wineglass-shaped and sclerotized. Anterior tooth 20 pm from anterior end of body, posterior tooth 13 pm behind first. Oesophagus 370 pm long; oesophago-intestinal glands well developed. Two glandular structures were observed at the base of the oesophagus, one anterior and another posterior to the oesophago-intestinal valve (Figure 2H). Similar structures were reported for Eutobrilus heptapapi/latus (Joubert & Heyns, 1979) Tsalolikhin, 1981 by Swart & Heyns (1988). Nerve ring 134 pm from anterior end. Numerous nerve ganglia present in vicinity of nerve ring, but no larger ganglia as seen in the Botswana specimen of Neotobrilus diversipapi/latus, could be observed. Excretory pore not seen. Intestine four cells in circumference. Rectum 39 pm long. Tail - 129 - almost straight, without a subterminal seta. Caudal glands inconspicuous; terminal spin neret small. Reproductive system didelphic-amphidelphic. Anterior and posterior branches 145 and 150 Jim long, respectively. Small round cells are present on the ventral side of the reproductive branches (Figure 2J). Vulva small, pore-like. Vagina weakly muscular. Uteri fairly long and narrow, without distinct pars dilatata uteri. No sphincter muscle, pars dilatata oviduc tus, or oviduct could be seen. Anterior and posterior ovaries 87 and 91 pm long, respect ively. No eggs or sperm cells present. Juvenile (Second stage) (n = 2): L = 0,68 & 0,75 mm; a = 32,4 & 30,0; b = 5,2 & 3,8; c = 6,0; c' = 5,4 & 6,9; anterior tooth = 14 & 20 pm from front end of body; posterior tooth = 22 & 25 Jim from front end of body; tail = 113 & 124 Jim General morphology similar to adult. Genital primordia distinct. Male Not found. Locality and habitat From soil among the roots of grasses next to an Acacia tree at the Lamont ruins, Chobe National Park, collected 26 July 1989. Specimens Female on slide RAU 4844, juveniles on slides RAU 4847 and 4850. - 130 - Panagrolaimus species cf australis (Cobb, 1893) Sudhaus, 1976 (Figure 3A-E) Three females from the Moremi Wildlife Reserve come close to the description by Yeates (1969) of New Zealand specimens of P. australis, especially regarding morphometrical data, general morphology and tail shape. The Botswana specimens, however, have a differently shaped head region (not narrowing markedly anterior as in P. australis), a differ ently shaped stoma (fused anterior part broader and more cylindrical vs narrower and more funnel-shaped in P. australis) and stomal teeth are apparently absent (three small teeth present in P. australis). Measurements Females (n = 3): L = 0,83 (0,5-0,98) mm; a = 28,9 (25,8-32,0); b = 5,3 (5,0-5,8); c = 15,8 (14,0-17,4); c' = 3,2 (3,1-3,4); V = 59 (59-60) %; tail = 53 (43-61) pm Description Body of heat-relaxed specimens moderately curved ventrad. Cuticle finely annulated, body pores not seen. Lateral field with two lines, 6 (5-7) pm wide or comprising 22 (13-29) % of corresponding body width. No hypodermal glands seen. Somatic muscles very dis tinct. Head region 9,5 (9,0-10,0) pm, continuous with body, somewhat truncate, not narrowing markedly anterior. Lips six, labial papillae distinct. Amphid apertures inconspicuous. Fused cheilostom, prostom and mesostom broad and cylindrical, 6,7 (6,0-8,0) pm long. Metastom and telostom narrow, 3,3 (3,0-3,5) pm long, individual rhabdia clearly demarcated. No distinct teeth could be seen in stoma. Oesophagus 157 (150-170) pm long. Corpus 63 (61-64) % of oesophagus length, broad, strongly muscular, separated from isthmus by distinct transverse markings. Isthmus relatively short, 31 (28-33) pm, weakly muscular. - 131 - Basal bulb ovoid, 26 (28-33) pm long, 20 (17-23) pm wide. A single oesophageal gland nucleus seen in one specimen. Cardia hemispheroid 6,3 (6,0-7,0) pm long. Nerve ring 119 (117-122) pm from anterior end of body, encircling isthmus at about its middle. Nerve ganglia not in abundance. Excretory pore, hemizonid and deirid could not be seen. Intestine with six cells in circumference, intestinal cells small with rather large nuclei. Rectum 20 and 22 pm long (n = 2) or 1,3 and 1,6 times the anal body width, rectal glands conspicuous. Tail elongate-conoid, distally slightly curved dorsad. Tail terminus acute. Numerous nerve ganglia present in tail region. Lateral field and phasmid inconspicuous. Two pairs of caudal papillae could be seen in one specimen (Figure 3D), one pair in another. Reproductive system panagrolaimoid. Vulva a long transverse slit with prominently raised lips. Postvulval uterine branch 22 (21-23) pm or 0,8 (0,6-0,9) body widths long. Sperma theca absent. Ovary reflexed, 290 (285-294) pm long, tip of germinal zone reaching almost to intestinal-rectal junction. Oocvtes distinct. No eggs or sperm cells present. Male and juvenile Not found. locality and habitat Specimens from soil among the roots of grasses on the northern side of the Kwai River Delta on the northern border of the Moremi Wildlife Reserve, collected 28 July 1989. Specimens On slides RAU 4873, 4882 and 4883. - 132 - PanagroJaimus hygrophiJus Bassen, 1940 (Figure 3F-J) Two female specimens from the Chobe National Park agree with the description of P, hygrophilus by Andrassy (1983), except for a more anterior vulva position viz. 42 and 48% vs 56% and a slightly larger body viz. 1,04 and 1,30 mm vs 0,95 mm. Measurements Females (n = 2): L = 1,04 & 1,30 mm; a = 39,3 & 39,4; b = 5,5 & 6,5; c = 8,32 (n = 1); c' = 7,5 (n = 1); V = 42 & 48 %; tail = 125 pm (n = 1) Description Body of heat-relaxed specimens almost straight to moderately curved ventrad. Cuticle finely annulated, body pores not seen. Lateral field indistinct. No hypodermal glands seen. Somatic muscle bands very distinct. Head region 7 and 10 pm wide, continuous with body, narrowing anterior. Lips six, labial papillae indistinct. Amphid apertures could not be seen. Fused cheilostom, prostom and mesostom cylindrical, 5,5 pm long. Metastom and telostom narrow, 2 pm (n = 1) long, individual rhabdia clearly demarcated. No distinct teeth seen in stoma. Oesophagus 190 and 200 pm long. Corpus 60 and 58 % of oesophagus length, strongly muscular, separa ted from isthmus by transverse markings. Isthmus relatively long, 48 and 58 pm, weakly muscular. Basal bulb ovoid, 22 and 24 pm long, 15 and 17 pm wide. No oesophageal gland nuclei could be seen. Cardia hemispheroid, 6 and 5 pm long. Nerve ring conspic uous in only one specimen, 115 pm from anterior end of body, encircling isthmus at anterior third. Nerve ganglia not in abundance. Hemizonid seen in one specimen (Figure 3H), opposite nerve ring. Excretory pore and deirid inconspicuous. Intestine seemingly with four cells in circumference, intestinal cells small with large nuclei. Rectum 24 pm - 133 - long (n = 1) or 1,5 times the anal body width, rectal glands conspicuous. Tail rather long, elongate-conoid, tail end sharply pointed. Caudal papillae could not be seen. Reproductive system panagrolaimoid. Vulva a long transverse slit, lips slightly raised. Postvulval uterine branch 25 pm or 1,5 and 1,1 body widths long. Spermatheca absent. Ovary reflexed, 370 and 366 pm long, tip of germinal zone reaching almost to intestinal rectal junction. Oocvtes distinct. No eggs or sperm cells present. Male and juvenile Not found. Locality and habitat Specimens from soil among the roots of grasses next to an Acacia tree at the Lamont ruins, Chobe National Park, collected 26 July 1989. Specimens On slides RAU 4846 and 4849. Hemicycliophora species cf labiata Colbran, 1960 (Figure 4) Three females from the Okavango are very similar to the South African populations of H. labiata reported by Van den Berg (1981 and 1990). The present specimens, however, have a slightly larger T/ABW value (3,5-4,2 vs 2,2-3,2), a longer stylet (76-80 pm vs 56,6-76,9 pm), slightly longer anterior oesophagus (from front end of body to middle of median bulb: 107-113 pm VS 74-106 pm), and longer tails (134 pm vs 62,5-121,0 pm). Van den Berg (1987) described Hemicycliophora specimens from the Cape which are very - 134 - similar to H. labiata, but have longer stylets (80,1-93,7 pm) and longer anterior oesopha gus (104-118 pm), corresponding in this regard to the Botswana specimens. However, her specimens differ from the present specimens in having shorter tails (83,5-93,0 pm vs 134 165 pm) and a longer distance between the vulva and anus (55,3-66,9 pm vs 35-55 pm). The discovery of further material will have to be awaited to decide whether the present specimens represent a variation of H. labiata or possibly a new species. Measurements Females (n = 3): L = 1,01; 1,13; 1,04 mm; a = 20,2; 24,0; 28,1; b = 6,0; 7,0; 6,2; c = 7,0; 6,8; 7,8; 0 = 7,8; 8,9; 7; V = 81; 86; 81 %; OV = 7; stylet = 77; 80; 76 pm; R = 226; 237; 246; RSt = 22; 18; 18; ROes = 46; 35; 41; Rex = 50; 41; 45; Rhem = 46; 37; 7; RV = 7; RVan = 7; 12; 12; Ran = 40; 42; 34; PV/ABW = 4,3; 5,2; 5,2; T/ABW = 3,5; 4,2; 3,7; VLNB = 4,5; 5,0; 5,4; St% L = 7,6; 7,0; 7,3 Description Body of heat-relaxed specimens almost straight to slightly curved ventrad. Lateral field a continuous single line. Lip region 19-20 pm wide, 5 pm high. Cephalic framework distinct. Stylet slender, metenchium slightly curved ventrad, 61-65 pm long, telenchium straight, 15 pm long. Stylet knobs 2,5-3,0 pm wide, 2-4 pm high. Opening of dorsal oesophageal gland 6 pm from base of stylet knobs (n = 2). Oesophagus 160-168 pm long, 107-113 pm from anterior end to middle of median bulb, 52-58 pm from the latter point to base of oesopha geal lobe. Excretory pore situated 4 and 7 annules posterior to base of oesophagus or 176 and 184 (n = 2) from anterior end of body. Hemizonid situated 3 or 4 annules anterior to excretory pore. Width at midbody 37-50 pm. Annules of outer cuticle somewhat flattened, 4-6 pm wide at midbody. Distance between vulva and anus 35-55 pm. Tail 134-165 pm long. - 135 - Male and juvenile Not found. locality and habitat Specimens from brackish soil among the roots of grasses, Boba Island in the Okavango Swamps, collected 1 August 1989. Specimens On slides RAU 5242 and 5243. Rotylenchus capensis Van den Berg & Heyns, 1974 The original description of this species by Van den Berg & Heyns (1974), was based on specimens collected in the Cape Province, South Africa. Van den Berg (1986) gave addi tional data and measurements of specimens from the Cape and Orange Free State, South Africa, as well as from Namibia. Nine females and a single male specimen from the Okavango agree very well with the above mentioned descriptions and illustrations, except that the Botswana specimens have a slightly wider lip region (11-13 Jim vs 8,5-11,4 Jim) and slightly wider body annules at midbody (2-3 Jim vs 1,5-2,2 Jim). Measurements Females (n = 9): l = 0,99 (O,90-1, 10) mm; a = 30,6 (25,6-34,8); b = 7,2 (6,O-7,8); b' = 6,3 (5,8-6,8); c = 58,9 (45,5-68,8); c' = 0,72 (O,50-1,OO); V = 55,3 (53,O-57,O) %; stylet = 30,6 (28,0-35,O) Jim; metenchium = 13,0 (11,O-16,O) Jim; telenchium = 17,6 (16,O-19,O) Jim; tail = 17,2 (14,O-22,O) Jim Male (n = 1): l = 0,79 mm; a = 29,3; b = 5,3; c = 35,9; c' = 1,2; stylet = 27 Jim; metenchium = 11 Jim; telenchium = 16 Jim; tail = 22 Jim; spicules = 33 Jim; gubernacu- - 136 - lum = 12pm Description Female Body posture ranging from moderately arcuate ventrad to almost a complete circle. Lateral field 4-8 Jim wide, with four lines, well aerolated in oesophageal region. Annules at midbody 2-3 pm wide. Lip region with five annules; 11-13 Jim wide, 6-8 pm high. Distance from dorsal oesopha geal gland opening to base of stylet knobs 3-5 Jim. Excretory pore distinct, 119-156 pm from anterior end. Hemizonid not seen. Basal bulb pyriform, 13-19 pm long, 11-14 pm wide. Distance from anterior end of body to middle of median bulb 80-102 pm, distance from the latter to basal margin of oesophageal lobe 53-75 pm. Phasmids situated 3-8 annules anterior to cloacal opening. Reproductive system didelphic-amphidelphic. Vulva a short transverse slit. Vagina almost cylindroid, uteri slender. Spermatheca present, filled with sperm cells. Ovaries very long, anterior ovary reaching almost to basal margin of oesophageal lobe or even more anterior, posterior ovary reaching almost to level of intestinal-rectal junction. Male Similar to female. Heat-relaxed body posture arcuate ventrad to assume the shape of a letter C. Phasmids situated at the level of cloacal opening. Juvenile Not found. - 137 - Locality and habitat All specimens from brackish soil among the roots of grasses, Boba Island in the Okavango Swamps, collected 1 August 1989. Specimens On slides RAU 5244 and 5246. Scutellonema cavenessi Sher, 1963 The first report of this species from southern Africa, was by van den Berg & Heyns (1973) from Angola and Namibia. It was described from Nigeria by Sher (1963), and has also been reported from the former Congo and the U.S.A. (Germani et et., 1985). Eight females and a single male specimen from the Chobe National Park, are in complete agreement with the abovementioned descriptions, as well as with the redescription by Germani et el., 1985. Measurements Females (n = 8): L = 0,72 (0,62-0,79) mm; a = 25,2 (21,9-34,3); b = 7,8 (7,1-8,5); b' = 5,9 (5,4-6,5); c = 37,0 (33,5-41,3) (n = 6); V = 56 (52-57) %; stylet = 23 (22-26) pm; m% = 44 (39-48); 0 = 19 (17-20) % tn = 3); scutellum: surface diameter = 2 (2-3) pm, inside diameter = 3,9 (3,5-4,5) pm; lip region width = 10 (9-12) pm; number of annules on lip region = 7 (n = 4); width of annules at midbody = 2 pm; excretory pore from anterior end = 99 (90-108) pm; lateral field as % of corresponding body width = 18 (13-22); tail = 20 (16-22) pm (n = 6); number of annules on tail = 12 (11-14); OV1 = 79 & 89 pm; OV2 = 91 & 90 pm (n = 2) Male (n = 1): L = 0,76 mm; a = 29,2; b = ?; b' = 5,3; c = ?; stylet = 25 pm; - 138 - m % = 48; 0 = 7; scutellum: surface diameter = 3 pm, inside diameter = 4 pm; lip region width = 12 pm; number of annules on lip region = 7; width of annules at midbody = 2 pm; excretory pore from anterior end = 7; lateral field as % of corresponding body width = 19; tail = 32 pm; number of annules on tail = 22; spicules = 30 pm; gubernaculum = 13 pm; capitulum = 7 pm Juvenile Not found. Locality and habitat From soil among the roots of grasses under mopane shrubs near the Savuti Marsh in the Chobe National Park, collected 27 July 1989. Specimens On slides RAU 5193, 5204-5206. ACKNOWLEDGEMENTS Thanks are due to the Foundation for Research Development of the CSIR for financial support and to Dr. Esther van den Berg for valuable advice. REFERENCES ANDRaSSY, I. 1983. The free-living nematode fauna of the Hortobaqv National Park. Akademiai Kiad6, Budapest: 31-46. ARGO, ANNE-DOROTHEE & HEYNS, J. 1973. New and little known species of the fami- - 139 - lies Monhysteridae and Tripylidae from South Africa. Phytophylactica 5: 149-154. CHITWOOD) B.G. & CHITWOOD} M.B. 1974. Introduction to Nematology. University Park Press 334 pp. GERMANI, G., BALDWIN, J.G., BELL, A.H. & WU, X. 1985. Revision of the genus Scutel lonema Andrassy, 1958 (Nematoda; Tylenchida). Revue de Nemstoloqie 8: 289 320. HEYNS, J. & COOMANS, A. 1980. Freshwater nematodes from South Africa 5. Chrono gaster Cobb, 1913. Nematologica 26: 187-208. JOUBERT, A.P. & HEYNS, J. 1979. Freshwater nematodes from South Africa 3. Tobrilus Andrassy, 1959. Journal of the Limnological Society of Southern Africa 5: 17-26. SHER, S.A. 1963. Revision of the Hoplolaiminae (Nematoda). 111. Scutellonema Andrassy, 1985. Nematologica 9: 421-443. SWART, ANTOINETTE & HEYNS, J. 1988. Redescription of Eutobrilus heptapapillatus (Joubert & Heyns, 1979) Tsalolikhin, 1981 with notes on its morphology and a possible excretory system. (Nematoda: Tobrilidae). Phytophylactica 20: 161-168. THORNE, G. 1961. Principles of Nematology. McGraw-Hili Co. New York. 553 pp. TSALOLIKHIN, S.Ya. 1983. (World fauna of nematodes of the families Tobrilidae and 1tipylidae. Keys to fauna of the USSR}. In Russian. Zoological Institute of the Academy of Sciences of the USSR 138. Leningrad, USSR; Nauka 233 pp. - 140 - TSALOLIKHIN S.Ya. 1985. [Nematodes of fresh and brackish waters in Mongolia Joint Soviet-Mongolian biological expeditions]. In Russian. Leningrad, USSR; Nauka, Leningradskoe otdelenie 114 pp. VAN DEN BERG, ESTHER 1981. Further studies on the genus Hemicycliophora de Man, 1921 in South Africa (Nematoda: Hemicycliophoridae) with a description of a new species. Phytophylactica 13: 181-194. VAN DEN BERG, ESTHER 1986. Two new Rotylenchus species from the Cape Province with notes on some known Rotylenchus species (Rotylenchinae: Nematoda). Phyto phylactica 18: 169-176. VAN DEN BERG, ESTHER 1987. Hemicycliophora species from the Cape Province with a key to the South African species (Hemicycliophoridae: Nematoda). Phytophylactica 19: 303-307. VAN DEN BERG, ESTHER 1990. Criconematidae from South Africa. Revue de Nemetotoqie 13: 361-368. VAN DEN BERG, ESTHER & HEYNS. J. 1973. South African Hoplolaiminae 2. The genus Scutellonema Andrassy, 1958. Phytophylactica 5: 23-40. VAN DEN BERG, ESTHER & HEYNS, J. 1974. South African Hoplolaiminae 3. The genus Rotylenchus Filipjev, 1936. Phytophylactica 18: 169-176. - 141 - YEATES, G.W. 1969. Three new Rhabditida (Nematoda) from New Zealand dune sands. Nematologiea 15: 115-128. (Submitted to Phytophylactica) - 142 - A B c D \ \\~ ~~'l!~/ E G 25 ACG 17,5 ' 500 I F Figure 2: Neotobrilus diversipapillatus (Daday, 1905) Tsalolikhin, 1981 A. Head region B. Region posterior to oesophago-intestinal glands showing large nerve ganglia C. Posterior branch of reproductive system D. Ventral view of tail E. Heat-relaxed body posture F. Cuticle showing minute striations Neotobrilus species G. Head region H. Oesophago-intestinal valve region showing glandular structures I. Tail region J. Reproductive system K. Heat-relaxed body posture L. Cuticle showing minute striations - 144 - I C~,'I\~~);"::<:":':::..,.;.r.,\ Jill t I~'~~'!' ~:.'.~." ~~~·~~111 it ~[f.- '_:---: ~~:f~~II: "/~/ ~ , I t,','l//;/(;:-;::.--=- I _ 'f 1//1. /"";:;f-=-- I , b;;L ~;<:c,: ',I 'r\I\~'''", ~#? , II\\ \,~~,~.. ~'~!'" ,,\\\.~,~~~::::.-:;:. I 1 , .... -c- ...... ::-.=- (I <>, ...... --::::- II t<,'-..::: )' I~'--- I !!i&tr!fii! I, ","~ .'''7' 'l E K F L ,100 pm f~:t~~~!~'~:~;:{fj 'BJ ,100pm ,e [ ,1001Jm 'I~:it~~~;-:~~~/ ,0 ,lmm IE '\:~t~·W ,50llm ,AGHI ,lmm .K ,251lm IF L Figure 3: Panagrolaimus species cf australis (Cobb, 1893)Sudhaus, 1976 A. Anterior region B. Head region C. Reproductive system D. Tail region E. Heat-relaxed body posture Panagrolaimus hygrophilus Bassen, 1940 F. Head region G. Reproductive system H. Anterior region I. Tail region J. Heat-relaxed body posture - 145 - E LSD urn ,lmm ,25 pm L 12 ,5 fJ m ,25pm Figure 4: Hemicycliophora species cf labiata Colbran, 1960 A. Tail region 8 and C. Anterior region D. Lateral field E. Spermatheca F. Heat-relaxed body posture - 146 - A B ,r~: :' Jt:",::,1 F E '''::·:·:::·:··-<:i·~: o -'- -~"- --',- -;- -'- _i_ _'_I- I -.L. -- -~;- , 50 llm ,500flm CHAPTER SIX On the identity of Tubixaba parva Pretorius, Kruger & Heyns, 1987 and Tubixaba tswanorum Nell & Heyns, 1987 (Nematoda: Aporcelaimidae) ABSTRACT Tubixaba parva Pretorius, Kruger & Heyns, 1987 is redescribed from type and other specimens, collected in the Kruger National Park and Chobe, Botswana, as well as from type specimens of Tubixaba tswanorum Nell & Heyns, 1987, collected at Letlakane, Botswana. These specimens showed variation in body length, odontostyle length, spicule length and number of ventromedian supplements. T. tswanorum is considered a synonym of T. parva. UITTREKSEL Oor die identifikasie van Tubixaba parva Pretorius, Kruger & Heyns, 1987 en Tubixaba tswanorum Nell & Heyns, 1987 (Nematoda: AporcelaimidaeJ Tubixaba parva Pretorius, Kruger & Hevns, 1987 word herbeskryf van tipe en ander eksemplare, versamel in die Kruger Nasionale Wildtuin en Chobe, Botswana, asook van tipe eksemplare van Tubixaba tswanorum Nell & Hevns, 1987, versamel by Letlakane, Botswana. Hierdie eksemplare het 'n variasie getoon in liggaamslengte, odontostekettenate, spikulumlengte en aantal ventromediane supplemente. T. tswanorum word beskou as 'n sinoniem van T. parva. - 147 - INTRODUCTION Tubixaba parva was first described by Pretorius, Kruger & Heyns (1987) from specimens found among the roots of grasses and Acacia trees outside the Malelane gate of the Kruger National Park. This species is· much smaller than the type species, Tubixaba tuxaua Monteiro & Lordello (1980), with a body length of 3,27-4,42 mm vs 10,7-12,8 mm. It is also more slender and has a shorter odontostyle than T. tuxaua. Nell & Heyns (1987) described a new species, Tubixaba tswanorum from specimens found in a mopane forest at Letlakane in Botswana. According to these authors T. tswanorum differs from T. parva in its greater body size, longer stylet, more ventromedian supplements and longer spicules. Examination of the type specimens of both species, however, re vealed very little morphological differences, especially in the head region. The cytoplasmic core in the tail of most specimens of T. parva is however curved ventrad and truncate terminally or slightly indented. This is not the case in the specimens of T. tswanorum, except in one male specimen where the cytoplasmic core is also slightly curved ventrad. The morphometric data of T. parva and T. tswanorum, however, show a continuous varia tion, except for the spicule length which is shorter in T. parva (79,8-87,8 pm vs 92-114 pm in T. tswanorum). Own measurements of the spicule length of the type specimens are, however, 84-94 pm in T. parva vs 97-116 pm in T. tswanorum. Botha & Heyns (1990) recorded a single male and female specimen of T. parva found among the roots of grasses near the Engelhard Dam in the Kruger National Park. These specimens are in correspondence to the type population of T. parva, except for a slightly longer odontostyle of 18 pm and longer spicules of 113 pm. This in turn is in agreement with the corresponding values for T. tswanorum (see Table 1). One male and six females recently collected from the bank of the Letaba River in the - 148 - Kruger National Park are in agreement with the type population of T. parva, but have slight ly longer bodies, corresponding in this respect to T. tswanorum (see Table 1). The spi cules of the Letaba specimens are quite short, but the ventromedian supplements more, as in T. tswanorum. The cytoplasmic core in the tail is not curved. One male, sixteen female and eleven juvenile specimens collected among the roots of grasses in the Chobe National Park, Botswana, were identified as T. parva. These agree well with the type population, except for slightly fewer ventromedian supplements and with quite a variation in shape of the cytoplasmic core of the tail. Considering the above, it seems that with the discovery of the new populations it has now become impossible to distinguish T. tswanorum from T. parva, and its synonymy with T. parva is therefore proposed. This implies that T. parva is a much more variable species than was originally suspected, and a redescription thereof is thus presented. MATERIALS AND METHODS Specimens were killed by gentle heat, fixed in FAA and processed into glycerine according to Thorne's slow method and mounted on permanent slides. Measurements and drawings were done with the aid of a Zeiss Standard 18 research microscope, equipped with a drawing tube. The body and all curved structures were measured along the median line. All measurements, except total body length are given in pm in the text as well as in the Table. - 149 - Tubixaba parva Pretorius, Kruger & Heyns, 1987 Syn. T. tswanorum Nell & Heyns, 1987 (Figures 1-3; Table 1) REDESCRIPTION Female Body relatively large and slender. Heat-relaxed body posture almost straight to slightly curved ventrad. Cuticle varying in thickness in different specimens, consisting of a thin exocuticle, thicker mesocuticle and thick endocuticle. Exocuticle with thin transverse striations, mesocuticle with radial striations. No punctations present. Lateral chord about one quarter to one fifth the corresponding body width; conspicuous hypodermal glands present. Lateral and ventral body pores distinct, dorsal pores limited to oesophageal region. Lateral pores about 306-460, starting as a single row behind lip region, but diverging into two rows at level of nerve ring, irregularly spaced. Ventral pores about 120-160, distribu ted over entire length of body, irregularly spaced. Dorsal pores about 6-15 in number, limited to oesophageal region, irregularly spaced. Lip region set off by a constriction, about one quarter as wide as body at base of neck in types and in specimens from Letaba and Chobe, one fifth in type specimens of T. tsws norum (= T. parva), according to own measurements. Lips rounded, partly amalgamated. Number and arrangement of labial papillae typically dorylaimoid. Oral aperture a dorsoven tral slit. Amphid aperture about one half the lip region width, situated at level of constric tion between lip region and adjoining body. Fovea stirrup-shaped, appearing to be divided in three sections in one specimen of the population from Letaba (Figure 1G). Amphideal fusus with sensilla not visible. Length of odontostyle about equal to lip region width. Stylet aperture about one third of - 150 - stylet length. Odontophore simple, more than one and one half times as long as odon tostvle, Guiding ring single, sclerotized, situated about one and a half lip region - widths from anterior end. Nerve ring distinct, encircling anterior part of oesophagus; numerous nerve cells visible. Hemizonid situated at level of nerve ring. Hemizonion not seen. Anterior slender part of oesophagus less muscular than basal expanded part, somewhat broadened around odontophore. A small mucro and one pair of endolids present in most of the specimens from Chobe. Oesophagus widening gradually from about 30-40 % from the anterior end. Position of the oesophageal gland nuclei and their outlets as follows: DO = 43-49,9 %; DN = 43,3- 52,1 %; S1N1 = 48,9-63,4 %; S1N2 = 58,0-65,4 %; ~N1 = 70,4-76,0 %; ~2 = 70,9-76,0 %; 5:201 = 70,9-77,8 %; ~02= 70,1-76,0 %; S10 is at the same level as ~N. Second pair of subventral nuclei very distinct and well developed; first pair of nuclei less well developed and sometimes obscure. Oesophago-intestinal disc absent. Cardia varying in shape and size, 12-20 pm long, 14-22 pm wide. Intestine four cells in circumference in present specimens and type specimens of T. tswanorum (= T. parva), filled with numerous yellow granules. Intestinal cells obscure in type specimens of T. parva. Junction between intestine and prerectum distinct in present specimens from Chobe and Letaba, indistinct in other specimens. Prerectum length about five to eight times the anal body diameter. Rectal glands seen in some specimens of the population from Chobe. Tail short, conoid and bluntly rounded. Cytoplasmic core of tail varying in shape from curved ventrad and truncate terminally or indented , to only curved ventrad and with the terminus not truncate or indented or not curved and the terminus not truncate to indented (Figure 2A-I). Caudal papillae variable in number and position, from two to five pairs, indistinct in some specimens. Reproductive system didelphic-amphidelphic, with both branches equally developed; the anterior and posterior branches occupying 13 (10-15) % and 13 (10-16) %, respectively of total body length in specimens from Chobe and Letaba, 15 % and 14 %, respectively in - 151 - holotype of T. parva, 12 % and 13 %, respectively in specimens of T. tswanorum (= T. parva). Ovaries reflexed, ovarial sac conspicuous in most specimens. Pars dilatata oviduc tus and pars dilatata uteri well developed, separated by distinct sphincter muscle. Pars dilatata oviductus pleated in some specimens of population from Chobe. Uterus and oviduct well developed. Ovejector not clearly differentiated in type and other specimens of T. parva, however, slightly better differentiated in specimens of T. tswanorum (= T. parva). Vagina reaching about 30-46 % of the corresponding body diameter, thick-walled and strongly muscular. Vulva a transverse slit without cuticularized lips. Sperm cells present in uterus as well as oviduct in type specimens, absent in other specimens. No uterine eggs observed. Male Similar to female, except posterior part of body more strongly curved ventrad. Reproduc tive system diorchic, testes opposed and outstretched. Sperm cells ovoid. Junction between vas deferens and rectum distinct in specimen from Chobe, indistinct in other specimens. Rectal glands seen in one specimen of T. tswanorum (= T. parva), ducts and outlets into cloaca not visible. Spicules arcuate, slender. One paratype specimen with distinctly wrinkled areas in the spicular sheath (Figure 3A). Lateral guiding pieces relatively slender, almost straight. Supplements papilliform, consisting of an adanal pair situated anterior to cloacal opening and a row of 7-14 irregularly spaced, non-contiguous ventrome dian ones. Tail similar to that of female, with similar variation in shape of the cytoplasmic core. Juvenile (1 Third-stage) tn = 2): L = 2,00-2,14 mm; a = 39,6-40,8; b = 4,9-5,0; c = 73,8-86,9; c' = 0,70-0,78; odontostyle = 13 Jim; odontophore = 25 Jim (n=1); total stylet = 38 Jim (n = 1); replacement odontostyle = 14 Jim; tail = 23-29 Jim - 152 - (? Fourth-stage) (n = 9): L = 2,56-2,89 mm; a = 40,8-50,0; b = 4,91-5,35; c = 66,1 96,3; c' = 0,7-0,9; odontostyle = 14-17 pm; odontophore = 21-26 pm; total stylet = 36-42 pm; replacement odontostyle = 14-18 pm; tail = 30-37 pm General morphology of juveniles similar to adults. Locality and habitat Present specimens from soil at the bank of the Letaba River near the Letaba Rest Camp, Kruger National Park, collected by J. Heyns in August, 1988 and from soil among the roots of grasses in the Chobe National Park, Botswana, collected by J. Heyns and A. Coomans in August 1989. Present specimens Kruger National Park specimens on slides RAU 4230, 4232, 4233 and Botswana speci mens on slides RAU 5113, 5115-5123, in the nematode collection of the Rand Afrikaans University, Johannesburg. Differential diagnosis T. parva can be recognized by the following characters: body relatively large viz. 3,19 4,97 mm; vulva position 46-57 %; odontostyle 14-19 pm; guiding ring 7-12 pm from anterior end; conspicuous lateral pores diverging into two rows in vicinity of nerve ring, about 306-460 in number; ventral pores about 120-160 in number; tail relatively short, 25-48 pm; spicules 77-114 pm. Relationships T. parva can be distinguished from T. tuxaua Monteiro & Lordello, 1980 by its much smaller body (9,44-11,66 mm in T. tuxaua), smaller odontostyle (30-33 pm in T. tuxaua), - 153 - shorter tail (73-120 pm in T. tuxaua), shorter spicules (195-206 pm in T. tuxaua) and absence of punctations in the cuticle. T. parva can be distinguished from the other Tubixaba species known from southern Africa viz. Tubixaba minima Botha & Heyns, 1990 by the following: larger body (1,72-2,12 mm in T. minima), more slender body (a = 39,0-69,2 in T. parva vs 29-34 in T. minima), larger number of lateral pores and ventral pores (75-94 and 41-52 respectively in T. minima), different level of divergence of lateral pores (diverge into two rows just anterior to anus in T. minima) and longer prerectum (203-408 pm in T. parva vs 118-1 70 pm in T. minima). ACKNOWLEDGEMENT Thanks are due to the Foundation for Research Development of the CSIR for financial support. REFERENCES BOTHA, ANNELIZE & HEYNS, J. 1990. Aporcelaimidae (Nematoda: Dorylaimida) from the Kruger National Park. Koedoe 33: 27-46. NELL, NADIA & HEYNS, J. 1987. A new species of Tubixaba Monteiro & Lordello, 1980 from Botswana (Nematoda: Dorylaimida). Phytophylactica 19: 483-436. PRETORIUS, E.M., KRUGER, J.C. DE WET & HEYNS, J. 1987. A new species of Tubixaba Monteiro & Lordello, 1980 (Dorylaimida: Aporcelaimidae) with an emendation of the genus. Koedoe 30: 41-47. (Published in the Afro-Asian Journal of Nematology 1) - 154 - TABLE 1: ~ data of ~~PretortUII. JI:ruger & 1\eyDI. 1967 l:.P"rYa 1:. tS""'lOrtln (~1:. fl:,,,'a) Kruger Natiooal Park Bot~-wana Bot~"-'3l1a Pretorfus et al. Betha & Heyns Present spe<:.imens Present; specl.ti=s Nell s Heyns (1987)- - (1990) (1990) n Ibiotype ParaT Paratypes Ibiotype pa~ar Paratypes 12 1200 1 ~ 1 6 6~ 1 <5 16 ~ 1 IS 700 L (am) 3.52 3.85(3.27-4.42) 3.BO(3.40-4.ZO) 3.67 3.77 4.28(3.98-4.54) 3.64 3.56(3.2~3.82) 3.66 4.22 4.49(4.34-4.59) 4,54( 4,OH.97) a 48.6 45.6(39.0-53.4) 45.5(41.5-51.2) 44 40 58(48-65.7) 56 51.8(44.3-58.7) 52.3 46.4 53,1(49.4-54,6) 1.8.1(51.9-f>9.2) b 5.4 6.1(5.1-7.9) 6.1(5.3-7.2) 7.8 5.1 6.7(6.1-7.4) 6.5 5.9(5.2-6.5) 6.0 5.9 5.4(4,4-6.0) 6.4(5,9-f>.7) e 103.0 112.8(78.8-144,4) 110(89.J-l39.0) 115 92 138(127. ~151.3) 134.8 89(79.5-100) 87.1 III 137(128-145) lJO(116-166) c' 0.74 0.71(0.55-0.82) 0.72(O,6:Hl.82) 0.7 0.82 0.67(0.6-{).75) 0.7 0.Jl4(0.7:Hl.93) 0.93 0.70 0,65(0.62-0.70) 0.72(0.66-{).BO) v,,; 46 53( 46-56) - 56 - 53.7(52-55) - 54(51.4-55.9) - 53.3 54.6(52.7-56,9) - Up regioo wl.dth 16 17(16-19) 17(15-19) 19 18 17.3(17-18) 19 16.9(15-18) 16 16 17(15-18) 17(17-19) Odonto.tyle: length 16 16(14-17) 16(15-17) 18 18 18(17-19) 16 16.8(16-16) 16 18 16(17-16) 17 wl.dth (4) [4-6) (4) 4.5 4,5 4.6(4-5) 4 4(4-5) 4 [4] [5! [4-5] Odontophore length 32,6(32-34.5) JO(29-3O) 28(22-32) t.l'I 27 26(25-28) 28(25-39) 33 33 - 27(25-29) 28 30 en Tota 1 stylet length 43 43.2(40-46) 45(40-45) 51 51.0 50.6(49-52.5) - 44(43-46) 44 46 47(46-48) 45(39-49) Stylet aperture: length [61 [7-10) (6-7) 5 5 8(7.5-<1.5) 6 6(5-7) - [7] [8] (6-81 :t of .tylet length 38 28-39 [38-44) 2B 28 42(32.5-47) J8 35.8(31-41) - (39] (44) [39-44) Qliding ring froll anterior en:1 10.5 10.2(8.5-11.5) 10.5(10.0-U.5) 11.5 12.5 11(10-12) 8 9(7-10) - 10 11(10-12) 11(9-12) />lJl>hid aperture: length (9) [10-14) [9) - 13 9.8(9-10.5) 10 9(6-12) - (9] - [81 :t of IIp r:egiCX1 wl.dth (56) [61-631 [50) - - 57(52.9-f>1.7) 56 55(35-70) - [53) 50 [501 Oesophagus length 645 625(505-674) 626(538-690) 470 740 643(610-675) 560 606(510-650) 610 719 836(750-1031) nO( f>8B.-813) Nerve ring frail anterior en:1 (167) [167) [172] - - 173 (ll'"1) 154 163(150-174) 153 [ 186) [162] [174-189] OJticle: neck (5] [4-51 [4-5] 3 3.5 3.7(3-4) 4.5 3.7(3.0-4.5) 4 [J.5) - 13.5) lIlid-body (7) 4.5-6.5 [6.51 7.5 - 8(7-9) 8 7(6-11) 6 [8] 4.4 [7J at the WI (6} 9.0-11.5 [IO} 13 11 1O.4(10-11)ll'"5 11 9.5(7-12) 9 (9) 7,5 [7-10) [ J. 0<.1l llJe3llUrements of type ~ped.Inens Figure 1: Tubixaba parva Pretorius, Kruger & Heyns, 1987 A. Head region (holotype) B. Head region (Tubixaba tswanorum ( = T. parva) (holotype) C. Head region (Letaba specimen) D. Head region (Chobe specimen) E. Dorso-ventral view of head region (Chobe specimen) F. Heat-relaxed body postures (Chobe and Letaba specimens) G. Shape of amphid (Letaba specimen) H. Lateral field (Chobe specimen) I. Vaginal region (Chobe specimen) - 156 - A D E F G ..... w~. If ~ ~ .~ I, H I I "w I ct Figure 2: Tubixaba parva Pretorius, Kruger & Heyns, 1987 A-H. Variation in female tail region A. Holotype B. Holotype (Tubixaba tswanorum = T. parva) C. Paratype D and E. Letaba specimens F-H. Chobe specimens I. Tail region of juvenile specimen from Chobe - 157 - A 8 c o E F G H I Figure 3: Tubixaba parva Pretorius, Kruger & Heyns, 1987 A-D. Variation in male posterior region A. Paratype B. Chobe specimen C. Letaba specimen D. Paratype (Tubixaba tswanorum = T. parva) Arrangement of ventromedian supplements E-F. Paratypes G. Letaba specimen H-1. Paratypes (Tubixaba tswanorum = T. parva) - 158- ...J A-D l10 0 um ---.l E-I l1.oo um F, E, , .G H, I - CHAPTER SEVEN A preliminary check list of the free-living and plant-parasitic nematodes of Botswana This check list follows the classification system of Andrassy (1976), except for the Dory- laimida and the Mononchida where the classification systems of Jairajpuri & Ahmad (1992) and Jairajpuri & Khan (1982), respectively, are used. Order Araeolaimida De Coninck & Schuurmans Stekhoven, 1933 Family Leptolaimidae Orley, 1880 Genus Chronogaster Cobb, 1913 *Chronogaster longicauda Heyns & Coomans, 1980 Order Rhabditida Chitwood, 1933 Family Cephalobidae Filipjev, 1934 Genus Acrobeles Von Linstow, 1877 *Acrobeles singulus Heyns, 1969 Genus Seleborca Andrassy, 1985 * Seleborca mariannae (Andrassy, 1968) Andrassy, 1985 *S. complexa (Thorne, 1925) Andrassy, 1985 Genus Zeldia Thorne, 1937 *Zeldia punctata (Thorne, 1925) Thorne, 1937 *Z. species cf punctata (Thorne, 1925) Thorne, 1937 Family Panagrolaimidae Thorne, 1937 Genus Panagrolaimus Fuchs, 1930 *Panagrolaimus species cf australis (Cobb, 1893) Sudhaus, 1976 * P. hygrophilus Bassen, 1940 - 159- Order Tylenchida Thorne, 1949 Family Hoplolaimidae Filipjev, 1934 Genus Scutellonema Andrassy, 1958 * Scutellonema cavenessi Sher, 1964 Genus Rotylenchus Filipjev, 1936 *Rotylenchus capensis Van den Berg & Heyns, 1974 Family Criconematidae Taylor, 1936 Genus Hemicyliophora de Man, 1921 *Hemicycliophora species cf labiata Colbran, 1960 Order Enoplida Chitwood, 1933 Family Tripylidae de Man, 1876 Genus Neotobrilus Tsalolikhin, 1981 *Neotobrilus diversipapillatus (Daday, 1905) Tsalolikhin, 1981 *Neotobrilus species Order Dorylaimida Pearse, 1942 Family Dorylaimidae de Man, 1876 Genus Mesodorylaimus Andrassy, 1959 * Mesodorylaimus usitatoides de Bruin & Heyns, 1992 Genus Prodorylaimus Andrassy, 1959 (*?)Prodorylaimus species Genus Laimydorus Siddiqi, 1969 * (?)Laimydorus species Genus Sicaguttur Siddiqi, 1971 Sicaguttur mopanicum (Van Reenen & Heyns, 1968) Carbonell & Coomans, 1986 Van Reenen & Heyns, 1986: 191-193 Family Aporcelaimidae Heyns, 1965 - 160- Genus Aporcelaimellus Heyns, 1965 *Aporcelaimellus adriaani Botha & Heyns, 1990 *A. micropunctatus (Bastian, 1865) Baqri & Khera, 1975 *A. parapapillatus Botha & Heyns, 1990 Genus Tubixaba Monteiro & Lordello, 1980 * Tubixaba parva Pretorius, Kruger & Heyns, 1965 Nell & Heyns, 1987: 433 Family Qudsianematidae Jairajpuri, 1965 Genus Labronema Thorne, 1939 *Labronema mauritiense Williams, 1959 Genus Eudorylaimus Andrassy, 1959 *Eudorylaimus diadematus (Cobb in Thorne & Swanger, 1936) Andrassy, 1959 * Eudorylaimus amabilis (Jairajpuri, 1965) Siddiqi, 1966 Genus Ecumenicus Thorne, 1974 *Ecumenicus monohystera (de Man, 1880) Thorne, 1974 Genus Discolaimus Cobb, 1913 *Discolaimus brevis Siddiqi, 1964 *D. major Thorne, 1939 Genus Discolaimium Thorne, 1939 * Discolaimium simplex Siddiqi, 1965 Genus D~comimoides Heyns,1963 * Discolaimoides bulbiferus (Cobb, 1906) Heyns, 1963 Family Actinolaimidae Thorne, 1939 Genus Neoactinolaimus Thorne, 1967 * Neoactinolaimus thornei Chaturvedi & Khera, 1979 Family Longidoridae Thorne, 1935 Genus Longidoroides Khan, Chawla & Saha, 1978 Longidoroides hooperi (Heyns, 1966) Jacobs & Heyns, 1982 - 161- Heyns & Coomans, 1991: 36 Genus Longidorus Micoletzky, 1922 Longidorus pisi Edward, Misra & Singh, 1964 Heyns & Coomans, 1991: 34 Family Xiphinematidae Dalmasso, 1969 Genus Xiphinema Cobb, 1913 Xiphinema stockeri Kruger & Heyns, 1985 Kruger & Heyns, 1985: 204 X. limpopoense Heyns, 1977 Heyns & Coomans, 1991: 29 X. elongatum Schuurmans Stekhoven & Teunissen, 1938 Heyns & Coomans, 1991: 29 X. setariae Luc, 1958 Heyns & Coomans, 1991: 29 X. variabile Heyns, 1966 Heyns & Coomans, 1991: 33 X. species cf X. meridianum group of species Heyns & Coomans, 1991: 33 Family Belondiridae Thorne, 1939 Genus Dorymimellus Cobb, 1913 *Dorylaimellus andrassyi Heyns, 1963 *D. directus Heyns, 1963 Family Leptonchidae Thorne, 1935 Genus leptonchus Cobb, 1920 *Leptonchus transvaalensis Heyns, 1962 Genus Proleptonchus Lordello, 1955 *Proleptonchus dieteri de Bruin & Heyns, 1992 Genus Tyleptus Thorne, 1939 * Tyleptus striatus Heyns, 1963 - 162- Family Nygolaimidae Thorne, 1935 Genus Nygomimus Cobb, 1913 *Nygolaimus anneckei Heyns, 1968 Genus Sofididens Heyns,1968 *Sofididens vulgaris (Thorne, 1930) Thorne, 1974 Order Mononchida Jairajpuri, 1969 Family Mononchidae Chitwood, 1937 Genus Mononchus Bastian, 1865 *Mononchus truncatus Bastian, 1865 Family lotonchidae Jairajpuri, 1969 Genus lotonchus (Cobb, 1916) Altherr, 1950 *Iotonchus parabasidontus Mulvey & Jensen, 1967 Family Mylonchulidae Jairajpuri, 1969 Genus Mylonchulus (Cobb, 1916) Altherr, 1953 * Mylonchulus minor (Cobb, 1893) Andrassy, 1958 *M. sigmaturus (Cobb, 1917) Altherr, 1953 Remarks 1. All species marked with * are new records for Botswana and are listed in this thesis. The Longidoridae and Sicaguttur mopanicum have been previously recorded from Botswana and references are given for these. 2. Eudorylaimus diadematus and E. amabilis were not included by Jairajpuri & Ahmad (1992) in their list of Eudorylaimus species. 3. Dorylaimellus directus was not included by Jairajpuri & Ahmad (1992) in their list of Dorylaimellus species. - 163- REFERENCES ANDRaSSY, I. 1976. Evolution as a Basis for the Systematization of Nematodes. London: Pitman Publishing. 289 pp. HEYNS, J. & COOMANS, A. 1991. Longidoridae from Botswana (Nematoda). Phytophylac tica 23: 29-37. JAIRAJPURI, M.S. & AHMAD, W. 1992. Dorylaimida. Free-living, Predators and Plant parasitic Nematodes. E.J. Brill. 458 pp. JAIRAJPURI, M.S. & KHAN, W.U. 1982. Predatory Nematodes (MononchidaJ with special reference to India. Associated Publishing Company-New Dehli, India. 129 pp. KRUGER, J.C. DE WET & HEYNS, J. 1985. The genus Xiphinema in southern Africa. XI. Description of Xiphinema stockeri n. sp. from Botswana (Nematoda: Dorylaimida). South African Journal ofZoology 20: 204-208. NELL, NADIA & HEYNS, J. 1987. A new species of Tubixaba Monteiro & Lordello, 1980 from Botswana (Nematoda: Dorylaimida). Phytophylactica 19: 433-436. VAN REENEN, ERINA & HEYNS, J. 1986. Medalinema mopanicum n. sp. from Botswana (Nematoda: Thornenematidae). Phytophylactica 18: 191-193. - 164- PART TWO Introduction Dujardin (1845) was the first to report on species of Mononchida, but the type genus Mononchus was, however, proposed only a few years later by Bastian (1865). Between 1865 and 1915 not much work was done on this group, until Cobb, (1916 and 1917) published the results of a comprehensive study, not only on the taxonomy and morpho logy, but also on its biology and ecology. Since then, several authors contributed signific antly towards the knowledge of this group, viz. Williams (1958), Andrassy (1959), Clark (1960a; 1960b; 1960c; 1961a; 1961b; 1961c; 1962 and 1963), Mulvey (1961a; 1961b; 1962; 1963a; 1963b and 1967), Buangsuwon & Jensen (1966), Yeates (1967) and Jensen & Mulvey (1968). A detailed historical review of the Mononchida can be found in Jairajpuri & Khan (1982). The Mononchida constitutes an important group of predatory nematodes occuring in soil and in freshwater. This group is of considerable importance to agriculture since there are indications that they can cause a significant decline in the population levels of plant parasitic nematodes. The first report on Mononchida occurring in southern Africa was by Heyns & Lagerwey (1965), who reported new and known lotonchus species from the Transkei and also from several localities in South Africa. Coetzee (1965; 1966a; 1966b; 1967; 1968a and 1968b) subsequently published a series of papers on the Mononchida of southern Africa. Numerous new and known species belonging to several genera were reported, viz. Cobbonchus, Granonchulus, Mylonchulus, totoncbus, Mononchus and Prionchulus. Coetzee (1968b) also provided a key to all the - 165 - known genera and species of southern African Mononchida. Since the last publication by Coetzee (1968b), numerous Mononchida specimens accumu lated in the nematode collections of the Rand Afrikaans University and the National collec tion of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. All of this material, as well as the types and other specimens used by Heyns & Lagerwey and by Coetzee, formed the basis of this study. The work presented here was undertaken to make a a further contribution towards the knowledge of southern African Mononchida. REFERENCES ANDRaSSY, I. 1958. Ober das system der Mononchiden (Mononchidae Chitwood,1937; Nematoda). Anna/es Historico-Natura/es Musei Nationalis Hungarici 50: 157-171. BASTIAN, H.C. 1865. Monograph on the Anguillidae, or free Nematoids, marine, land, and freshwater; with descriptions of 100 new species. Transaction of the Umnotoqicsl Society of London 25: 73-184. BUANGSUWON D.K. & JENSEN H.J. 1966. A taxonomic study of Mononchidae (Enoplida: Nemata) inhabiting cultivated areas of Thailand. Nemetotcqice 12:259-274. CLARK, W.C. 1960a. The oesophago-intestinal junction in the Mononchidae (Enoplida: Nematoda). Nemetoloqice 5: 178-183. CLARK, W.C. 1960b. Redescription of Mononchus truncatus Bastian, M. papillatus Bastian and Prionchu/us muscorum (Dujardin) (Enoplida, Nematoda). Nemetotoqice 5: 184 198. - 166 - CLARK, W.C. 1960c. New Zealand Mononchidae (Enoplida, Nematoda) I. The genera Mononchus Bastian and Prionchulus Cobb. Nematologica 5: 199-214. CLARK, W.C. 1961 a. The Mononchidae (Enoplida, Nematoda) of New Zealand II. The genus lotonchus (Cobb, 1916) Altherr, 1950. Nematologica 5: 260-274. CLARK, W.C. 1961 b. The Mononchida (Enoplida, Nematoda) of New Zealand III. A review of the genus Cobbonchus Andrassy, 1958 with description of new species. Nemato logica 5: 275-284. CLARK, W.C. 1961 c. The Mononchidae (Enoplida, Nematoda) of New Zealand IV. The genus Mylonchulus (Cobb, 1916) Pennak, 1953. Nematologica 6: 1-6. CLARK, W.C. 1962. Evolution within the family Mononchidae (Enoplida, Nematoda). Nematologica 7: 252-255. CLARK, W.C. 1963. Notes on the Mononchidae (Nematoda) of the New Zealand region with description of new species. New Zealand Journal of Science 6: 612-632. COBB, N.A. 1916. Notes on new genera and species of Nematodes. 4 subdivisions of mononchs. Journal of Parasitology. 2: 195-196. COBB, N.A. 1917. The Mononchida (Mononchus Bastian, 1865). A genus of free-living predatory nematodes. Soil Scientist 3: 431-486. COETZEE, VICTORIA. 1965. South African species of the genus Cobbonchus Andrassy, 1958 (Nematoda: Mononchidae). Nematologica 11: 281-290. - 167 - COETZEE, VICTORIA. 1966a. Species of the genera Granonchulus and Cobbonchus (Mononchidae) occuring in southern Africa. Nematologica 12: 302-312. COETZEE, VICTORIA. 1966b. Species of the genus Mylonchulus (Nematoda: Mononchi dae) occuring in southern Africa. Nematologica 12: 557-567. COETZEE, VICTORIA. 1967. Species of the genus lotonchus (Nematoda: Mononchidae) occuring in southern Africa. Nematologica 13: 367-377. COETZEE, VICTORIA. 1968a. Southern African species of the genera Mononchus and Prionchulus (Mononchidae). Nematologica 14: 63-76. COETZEE, VICTORIA. 1968b. Mononchidae (Nematoda) of southern Africa. South African Journal ofAgricultural Science 11: 403-414. DUJARDIN, F. 1845. Histoire Naturelle des Helminthes ou vers intestinaux. Paris. 645 pp. HEYNS, J. & LAGERWEY, GERDA. 1965. South African species of the genus lotonchus Cobb, 1916 (Nematoda: Mononchidae). South African Journal of Agricultural Science 8: 775-784. JAIRAJPURI, M.S. & KHAN, W.U. 1982. Predatory Nematodes (Mononchida) with special reference to India. Associated Publishing Company-New Dehli, India. 129 pp. JENSEN, H.J. & MULVEY, R.H. 1968. Predaceous Nematodes (Mononchidae) of Oregon. Oregon State University Press 1-57. - 168 - MULVEY, R.H. 1961 a. The Mononchidae. A family of predaceous nematodes I. Genus Mylonchulus (Enoplida: Mononchidae). Canadian Journal of Zoology 39: 665 696. MULVEY, R.H. 1961 b. The Mononchidae. A family of predaceous nematodes II. Genus Anatonchus (Enoplida: Mononchidae). Canadian Journal ofZoology 39: 807-826. MULVEY, R.H. 1962. The Mononchidae. A family of predaceous nematodes III. Genus Miconchus (Enoplida: Mononchidae). Canadian Journal of Zoology 40:65-81. MULVEY, R.H. 1963a. The Mononchidae. A family of predaceous nematodes IV. Genus lotonchus (Enoplida: Mononchidae). Canadian Journal ofZoology 41: 79-98. MULVEY, R.H. 1963b. The Mononchidae. A family of predaceous nematodes V. Genus Sporonchutus, Granonchulus and Sporonchuloides n. gen. (Enoplida: Mononchidae). Canaclian Journal ofZoology 41: 763-774. MULVEY, R.H. 1967. The Mononchidae. A family of predaceous nematodes VI. Genus Mononchus (Nematoda: Mononchidae). Canadian Journal ofZoology 45: 915-940. WILLIAMS, J.R. 1985. Studies on the nematode soil fauna of sugarcane fields in Mauritius. I. The genus Mononchus (Trilobidae, Enoplida). Mauritius Sugar Industry Research Institute, Occasional Paper 1: 1-13. YEATES, G.W. 1967. Studies on nematodes from dune sands. B. Oncholaimidae, Ironidae, Alaimidae and Mononchidae. New Zealand Journal of Science 10: 299-321. - 169 - CHAPTER ONE Mononchida (Nematoda) of southern Africa: genera Mononchus Bastian, 1865, Clarkus Jairajpuri, 1970 and Coomansus Jairajpuri & Khan, 1977 ABSTRACT Descriptions and illustrations are given for Mononchus aquaticus Coetzee, 1968; Mono- nchus truncatus Bastian, 1865; Clarkus sheri (Mulvey, 1967) Jairajpuri, 1970; Clarkus papil/atus (Bastian, 1865) Jairajpuri, 1970 and Coomansus parvus (de Man, 1880) Jairaj puri & Khan, 1977. Mononchus bel/us Andrassy, 1985 is considered a synonym of Mononchus truncatus. An identification key is given for the southern African species. UITTREKSEL Mononchida (Nematoda) vanaf suider Afrika: genera Mononchus Bastian, 1865, Clarkus Jairajpuri, 1970 en Coomansus Jairajpuri & Khan, 1977 Beskrywinqs en tvntekeninae word gegee vir Mononchus aquaticus Coetzee, 1968, Mononchus truncatus Bastian, 1865, Clarkus sheri (Mulvey, 1967) Jairajpuri, 1970, Clarkus papillatus (Bastian, 1865) Jairajpuri, 1970 en Coomansus parvus (de Man, 1880) Jairajpuri & Khan, 1977. Mononchus bellus Andrassy, 1985 word beskou as 'n sinoniem van Mononchus truncatus, 'n Identifikasie sleutel vir die spesies van suider Afrika word gegee. - 170 - INTRODUCTION Coetzee (1968) was the first to report on Mononchus species occurring in southern Africa. She described four new species namely, M. pretoriensis (= Coomansus pretoriensis) from Pretoria, Transvaal, M.parvu/us (= Coomansus parvu/us), now regarded as a synonym of Coomansus parvus (de Man, 1880), from Fouriesburg, Orange Free State, M. juga/is (= C/arkus juga/is), now regarded as a synonym of C/arkus sheri from Wellington, Cape Province and M. aquaticus from Gobabeb, Namibia. Further species reported by Coetzee were M. truncatus and M. papillatus (= C/arkus papillatus) from various localities in South Africa. Since the publication by Coetzee (1968), further Mononchidae specimens from South Africa, Botswana, Swaziland and Namibia accumulated in the nematode collections of the Rand Afrikaans University and the National Collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. All of this material, as well as the types and other specimens used by Coetzee, were available for study. MATERIALS AND METHODS Specimens were killed by gentle heat, fixed in FAA and processed into glycerine according to Thorne's slow method and mounted on permanent slides. Measurements and drawings were done with the aid of a Zeiss Standard 18 research microscope, equipped with a drawing tube. The body and all curved structures were measured along the median line. Buccal cavity measurements do not include the lip, vestibule leading into the cavity, the anterior oblique plates, or the cavity walls. Cavity width was taken at the broadest part. Measurements of the dorsal tooth apex and the subventral ribs were taken from the anterior. vertical plates and calculated as a percentage of the buccal cavity length. All measurements are given in pm, unless stated otherwise. - 171 - TAXONOMY Genus Mononchus Bastian, 1865 Mononchus (senso stricto) with type species Mononchus truncatus, has poorly developed lips and labial papillae, buccal cavity elongate-cylindroid, spicules and accessory pieces extremely long and slender, tail elongate with rounded terminus and caudal glands, ducts and spinneret well developed (Jairajpuri, 1970). Mononchus truncatus Bastian,1865 and Mononchus aquaticus Coetzee, 1968 are two closely related species. Mononchus truncatus was first described by Bastian (1865) from Falmouth, England. Clark (1960) gave a redescription of this species, designating a neotype from specimens collected at the type locality. He synonymized several species with M. truncatus and also mentioned that Andrassy (1958) was the first to draw attention to the variability of this species. Mononchus aquaticus was described by Coetzee (1968) from the Kuiseb River bed in Gobabeb, Namibia. Specimens were also reported from the Cape Province, Natal and Transvaal in South Africa, mostly found in water or in the vicinity of water. According to Coetzee, M. aquaticus is very closely related to M. truncatus Bastian, 1865, except for a smaller stoma (buccal cavity), more posteriorly situated amphids and a stouter tail. In M. aquaticus the indentation in the anterior subventral wall of the buccal cavity is normally situated anterior to, or at the same level as the dorsal tooth apex and the refractive trans verse thickening is usually posterior to this level. Jairajpuri (1970) identified ten female specimens from India as M. aquaticus. He states that if the variation of M. truncatus as given by Andrassy (1958) and Mulvey (1967) is accep- - 172 - ted, there are no characters left which distinguish M. aquaticus from M. truncatus, and it could be regarded as a synonym of M. truncatus. 8aqri & Jairajpuri (1972) gave a very comprehensive description, as well as numerous illustrations of M. aquaticus. They had at their disposal three female paratypes as well as all the Indian specimens of M. aquaticus, the neotype of M. truncetus, as well as some additional specimens of M. truncatus from Mulvey. After comparing the various popula tions of M. truncatus and M. equeticus, they confirmed the validity of M. aquaticus as a separate species. Andrassy (1985) described a new species Mononchus bel/us from Puerto Rico, Argentina and Hungary. According to him M. bel/us is closely related to both M. truncatus and M. equsticus, differing in the position of the dorsal tooth apex (M. bel/us = 30-33%; M. truncatus = 22-28% and M. aquaticus = 19-23%) and in the level of the subventral transverse ribs in the buccal cavity (situated before the dorsal tooth apex in M. bel/us). M. aquaticus can also be easily distinguished from the other two species by the much smaller buccal cavity. Loof (1990) regarded M. bel/us Andrassy, 1985 as a possible synonym of M. truncetus, with which the author tends to agree. The position of the dorsal tooth apex in M. truncatus is quite variable viz. 19-33% (see Table 2) (19 % = calculated from Figure 28 of Andrassy, 1985) and the measurements of M. bel/us given by Andrassy (1985), falls within this range. The position of the subventral ribs is also more or less the same in both M. truncatus and M. bel/us (see Table 2). It is the variation in the position of the dorsal tooth apex which gives rise to the ribs being either anterior to, or posterior to the tooth apex. Thus, in specimens with the dorsal tooth apex more posterior, the ribs will be anterior to the tooth apex (as in M. bel/us). In specimens with a more anterior tooth apex, the ribs will be posterior to the apex. However, the author refrains from making a formal synonymization, since the types or other specimens of M. bel/us have not been studied. - 173 - Mononchus aquaticus Coetzee, 1968 (Figure 1; Table 1) For list of synononyms, see Andrassy (1985) M. aquaticus seems to be a cosmopolitan species and has subsequent to the reports by Coetzee (1968), Jairajpuri (1970) and Baqri & Jairajpuri (1972) also been recorded by Zullini from Italy (1971) and Mexico (1973); Grootaert (1976) from the North-Western Sahara; Jairajpuri & Khan (1982) from India; Winiszewska (1985) from Poland and Chaves (1990) from Argentina. Grootaert & Maertens (1976) established a population in a labora tory in Belgium, and Small & Grootaert (1977) described males from this cultivated popula tion. Twenty six female specimens from Windhoek, Namibia and from Leslie, South Africa were identified as M. aquaticus. These are in full agreement with previous descriptions of this species. Description Female Cuticle finely striated, mesocuticle sometimes irregularly separated from rest of cuticle. Lateral field 36 (28-47) % of corresponding body width wide; no lateral, dorsal or ventral pores seen. Lip region continuous with adjoining body; papillae distinct. Amphid aperture small, ante rior to dorsal tooth apex, 10 (7-13) pm from anterior end. Fovea cup-shaped in specimens from Windhoek, mostly indistinct in specimens from Leslie; amphidial canal inconspic uous. Buccal cavity narrow, walls about 2 pm thick, anteriorly finely striated. Indentation - 174- of anterior subventral vertical plate posterior to dorsal tooth. Dorsal tooth apex at 20 (16 22) % of buccal cavity length. One pair of geusids sometimes visible, opening subventrad into buccal cavity. Oesophagus strongly muscular; oesophageal gland outlets distinct in most specimens, gland nuclei however mostly inconspicuous, except in a few specimens from Windhoek. One pair of endolids seen in the lumen of one specimen. Nerve ring dis tinct; excretory pore just posterior to nerve ring in specimens from Windhoek, inconspic uous in specimens from Leslie. Vulva transverse with moderately sclerotized lips. No advulval papillae present. Vagina with sclerotized pieces. Vulval glands, as reported by Baqri & Jairajpuri (1972), not observed. Sphincter muscle present between uterus and oviduct, but difficult to discern. Ovaries well developed with numerous oocvtes. No eggs or sperm cells present in repro ductive branches. Tail elongate-conoid in anterior half, curved ventrad in posterior half, ending in a rounded termimus. Three caudal glands mostly conspicuous in specimens from Windhoek; arranged in tandem and ending in an ampulla through a common duct. Spinneret terminal, seemingly armed. One pair of lateral caudal papillae seen. Intestine four or six cells in circumference, filled with numerous yellow granules. Rectal glands sometimes evident. Male and juvenile Not found. Locality and habitat Present specimens from a water-furrow next to the road en route to Leslie in the Transvaal and from soil among the roots of grasses at the Daan Viljoen Nature Reserve, Windhoek in Namibia, collected by I. Botha, 1 February 1972 and by A. Coomans and J. Heyns 22 July 1986, respectively. - 175 - Specimens Transvaal specimens on slides 10181, 10185, 10186, 10189-10192, 10194 in the National Collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. Namibian specimens on slides RAU 2974-2977, 2979, 2981, 2983 2985 in the nematode collection of the Rand Afrikaans University, Johannesburg. Mononchus truncatus Bastian, 1865 (Figure 2; Table2) For list of synononyms, see Andrassy (1985) Coetzee (1968) identified specimens from various localities in South Africa as M. trunca tus. She gave no morphometrical data, but mentioned that these specimens differ from the redescription by Clark (1960) only in the more anteriorly situated amphids. This discrepancy is resolved by the findings of Coomans & Khan (1981), who restudied the neotype and found that the amphid is in a far more anterior position than shown by Clark, viz. just behind the lateral lip. Three female and four juvenile specimens from Botswana were identified as M. truncatus. Also available for study were a few females from Barberton and Hoedspruit in the Trans vaal, previously identified by Coetzee (1968) as this species, and from Parys in the Orange Free State. All these specimens agree well with the redescription by Clark (1960), except that lateral fields are distinct in the present specimens. Description Female Body almost straight when heat-relaxed, only tail tip slightly curved ventrad. Cuticle with - 176- fine transverse striations, mesocuticle sometimes irregularly separated from rest of cuticle. Lateral field about one fourth to one third of corresponding body width. Body pores not seen, except in one specimen where ventral pores are present just anterior to anus. Lip region slightly offset, 26 (23-28) pm wide. Amphids 9 (8-10) pm from anterior end in specimens from Botswana and Hoedspruit, indistinct in other specimens. Fovea cup shaped, amphidial canal sometimes visible. Buccal cavity elongate-ovoid, walls about 3 pm thick, posterior vertical plates finely striated. Dorsal tooth apex at about one third of buccal cavity length. Indentation of anterior subventral vertical plates anterior to dorsal tooth apex. One pair of geusids opening subventrad into buccal cavity. Oesophageal gland nuclei and outlets mostly distinct. Nerve ring located 148 (143-155) pm from anterior end in specimens from Botswana, obscure in specimens from Barberton, Hoedspruit and Parys. Excretory pore not seen. Vulva a transverse slit with moderately developed sclerotized pieces. Vagina with sclero tized pieces. Uterus short; no eggs in the Botswana specimens, one egg present in either one uterus or both uteri in most of the specimens from Barberton and Hoedspruit. Sphinc ter muscle between uterus and oviduct quite distinct. Ovaries well developed with numerous oocvtes. Female tail conoid at first, tapering gradually to become more cylindri cal, ending in a rounded terminus. Three caudal glands present, arranged in tandem. Ampulla distinct; spinneret terminal. Two sublateral papillae present just anterior to tail terminus. Coelomocytes sometimes seen in tail region. Intestine six or eight cells in circumference. Rectum 31 (29-33) pm long. Male Not found. - 177 - Juveniles General morphology similar to adults. Locality and habitat From wet soil among the roots of a sausage tree (Kigelia africana) standing on the edge of the water on Boba Island, Okavango, Botswana, collected by J. Heyns and A. Coomans, 1 August 1989; from the bank of the Queens River en route to Barberton, Transvaal, col lected by J. Heyns, 3 June 1963; from soil among the roots of lemon trees near the "Blyde Trading Store" between Hoedspruit and the Strydom tunnel, Hoedspruit, Transvaal, collected by J. Heyns, G. Lagerwey and C. van Zyl, September 1963 and from Parys, Orange Free State, collected by J. Heyns, September 1963. Specimens Botswana specimens on slides RAU 5271-5274 in the nematode collection of the Rand Afrikaans University, Johannesburg; other specimens on slides 1763, 2184 and 2971 in the National Collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. Genera Clarkus Jairajpuri, 1970 and Coomansus Jairajpuri & Khan,1977 Jairajpuri (1970) proposed a new genus Clarkus for those species of Mononchus (sensu Iato) with lips and labial papillae prominent, buccal cavity barrel-shaped, with or without a non-denticulate ventral ridge, spicules and accessory pieces short and stout, tails conoid, arcuate ventrad, caudal glands poorly developed or absent and spinneret absent or incon spicuous. Jairajpuri & Kahn (1977) subdivided the genus Clarkus into Clarkus (sensu stricto), repre- - 178 - sented by the type species, C. papillatus, having a non-denticulate ridge and Coomansus which is without such a ridge. C/arkus sheri (Mulvey, 1967) Jairajpuri, 1970 Syn: C/arkus juga/is (Coetzee, 1968) Jairajpuri, 1970 (Figure 3; Table 3) This species was first described by Mulvey (1967) from Riverside, California, U. S. A. Coetzee (1968) described a new species, Mononchus juga/is (= C/arkus jugalis) from several localities in South Africa, with the type locality Wellington in the Cape Province. In the diagnosis, she stated that C/arkus juga/is is close to Mononchus papillatus (= C/arkus papillatus). Jairajpuri (1970) and Andrassy (1983), however, regard C/arkus jugalis as a synonym of C/arkus sheri, with which the author is inclined to agree. Zullini (1977) recorded one female specimen of C/arkus sheri from Fortin de Flores, Central Mexico. In this specimen, the buccal cavity is slightly wider, the amphids are situated slightly more posterior and the tail is less arcuate. This is in agreement with the descrip tion of C. juga/is by Coetzee (1968). Two males and fourteen females from Piggs Peak, Ventersdorp, Pretoria, Blydepoort, Newcastle, Pinetown and Fauresmith, were available for study. These specimens agree well with previous descriptions of C. sheri, except for a slightly wider lip region, longer spicules and slightly longer gubernaculum and lateral guiding pieces. Description Female and male Cuticle. with fine transverse striations, mesocuticle sometimes irregularly separated from rest of cuticle. Lateral field about one quarter of corresponding body width wide. Body - 179 - pores indistinct, except lateral pores sometimes seen just anterior to tail region in female; in male, ventral pores are visible in the region just posterior to the oesophagus and again towards the beginning of the supplements. Lip region truncate, well developed and slightly offset. Position of amphid apertures varying from base of lip region to about half-way between beginning of anterior vertical plates and dorsal tooth apex. Fovea cup-shaped, amphidial canal inconspicuous. Buccal cavity ovoid, walls about 2-3 pm thick, striations sometimes visible. Ventral ridge distinct. One pair of geusids opening subventrad into buccal cavity. Oesophageal gland nuclei and outlets mostly evident. Nerve ring distinct in specimens from Piggs Peak, Ventersdorp, Blydepoort and Pretoria, obscure in other specimens. Excretory pore and duct distinct, just posterior to nerve ring. Female Vulva a transverse slit with slightly thickened lips. Vagina with well developed sclerotized pieces and surrounding musculature. Reproductive branches well developed in specimens from Piggs Peak, Ventersdorp, Blydepoort and Pretoria , less well developed in specimens from Pinetown and Newcastle, difficult to discern in specimens from Fauresmith. One egg measuring 81 x 50 pm present in posterior uterus of one Piggs Peak specimen. Sphincter muscle present between uterus and oviduct, although not always very distinct. Pars dilata ta oviductus well developed. Ovaries with numerous oocvtes, Tail conoid, arcuate ven trad. Caudal glands and spinneret absent. Caudal papillae comprising one to three lateral pairs. Hyaline core 8 (5-9) pm long. Intestine six to fourteen cells in circumference. Rectum 34 (23-43) pm long. Male Diorchic, testes opposed and outstretched. Anterior testis 254-340 pm, posterior testis 231-270 pm. Sperm cells ovoid, about 4 pm in diameter. Three ejaculatory glands - 180 - observed. Supplements papilloid, non-contiguous. Spicules arcuate. Termini of lateral guiding pieces not clear, but seemingly not bifurcated as mentioned in original description. Gubernaculum crescent-shaped. Rectal glands present, ducts however indistinct. Tail shape similar to that of female. Caudal glands and spinneret absent. Caudal papillae comprising three lateral pairs. Hyaline core 7-9 Jim long. Intestine eight to ten cells in circumference. Rectum 33 (23-40) Jim long. Locality and habitat From soil among the roots of grasses next to the road en route to Piggs Peak, two kilo metres after the Oshoek turnoff, Swaziland, collected by J. Heyns and M. Luc, November 1984; from soil on the farm "Syferfontein", Ventersdorp; from soil underneath the damwall on the plot of Mr. M.G. Louw, Pretoria and from soil among the roots of indige nous plants behind chalet 41 at the H. F. Odendaal camp, Blydepoort, Transvaal, collected by E. van den Berg, 1 March 1980 and 5 February 1981 and by J. Heyns and A. Coomans, July 1984, respectively; from soil among the roots of natural vegetation on the farm "Eikenhof", Newcastle and from soil among the roots of Tagetes minuta in the "Wye bank" area, Pinetown, Natal, collected by C.H. Hendriks, 12 October 1978 and by K.P.N. Kleynhans and D.P. Keetch, 16 March 1981, respectively; from soil among the roots of natural vegetation at the Philippolis turnoff in Fauresmith, Orange Free State, collected by E. van den Berg, 6 February 1980. Specimens Present specimens from Piggs Peak and Blydepoort on slides RAU 1583, 1589, 4993 in the nematode collection of the Rand Afrikaans University, Johannesburg. Other specimens on slides 15358, 15361, 17390, 18305, 18310, 18312,18535,19823,19907,19908 and 19910 in the National Collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. - 181 - Clarkus papillatus (Bastian, 1865) Jairajpuri, 1970 (Figure 4; Table 4) For a detailed discussion of the taxonomic uncertainties and nomenclatorial problems concerning Bastian's species and the species identified and described as Mononchus papil latus by Butschli in 1873, together with Dujardin's Oncholaimus muscorum (Prionchulus muscorum), see Andrassy (1958) and Clark (1960). Since the author does not believe that it is possible to determine with any certainty the identity (and conspecificity or not of any of these species), Clark's (1960) redescription and designation of a neotype (from the type locality) for Mononchus papillatus Bastian 1865 (= Clarkus papillatus) is accepted. For these and other reasons the author does not agree with the actions taken by Zell (1985). In view of the past confusion concerning Bastian's M. papillatus, BOtschli's M. papillatus and Dujardin's Oncholaimus muscorum, most of the older distribution records for these species (dating from before about 1958) are regarded as uncertain. Coetzee (1968) identified specimens from the Cape and Transvaal as C. papillatus, but gave no description or morphometrical data. Illustrations of the female head and tail correspond well to those of Clark (1960). Since Coetzee's recording of C. papillatus from South Africa, females from Mont-aux Sources, Franschhoek and Grabouw were identified as this species. These specimens agree well with previous descriptions, except for a shorter tail and the presence of a lateral field. Description Female Cuticle with distinct, but fine striations, mesocuticle mostly irregularly separated from rest of cuticle in Franschhoek specimens. Lateral field about one quarter the corresponding - 182 - body width wide. Lateral pores visible in neck region of some specimens, but no dorsal or ventral pores could be seen. Lip region slightly offset; papillae distinct. Amphid aperture just anterior to dorsal tooth apex 10 (8-12) pm from anterior end in specimens from Franschhoek and Mont-aux Sources, indistinct in specimens from Grabauw , except in one, where it is situated just posterior to the dorsal tooth apex. Fovea cup-shaped; amphidial canal inconspicuous. Buccal cavity ovoid, walls about 1-2 pm thick, without striations. Ventral ridge distinct. One pair of geusids opening into buccal cavity, visible in some specimens. Oesophagus muscular, more strongly so in posterior third. All oesophageal gland outlets, as well as dorsal gland nucleus, visible in most specimens; other gland nuclei however inconspicuous. One pair of endolids seen in oesophageal lumen in two specimens. In one specimen, two outlets and in another, three outlets can be seen anterior to the dorsal gland outlet, one outlet associated with a small glandular organ (Figure 4A and B). Nerve ring difficult to discern in specimens from Grabouw, faintly visible in specimens from Mont-aux-Sources and Franschhoek. Excretory pore seen just posterior to nerve ring in specimen from Mont aux-Sources. Vulva a transverse slit with thickened lips. Vagina muscular, strongly sclerotized pieces present in specimens from Mont-aux-Sources and Franschhoek, less strongly sclerotized pieces present in specimens from Grabouw. Ovejector present. No sphincter muscle observed at uterus-oviduct junction. No sperm cells present in reproductive branches. One egg present in each uterus in a specimen from Franschhoek, measuring 90 x 39 pm and 88 x 42 pm. Another specimen with one egg in the posterior uterus, measuring 90 x 32 pm. Tail elongate-conoid, arcuate ventrad with a rounded terminus. Caudal glands not seen; spinneret absent. Caudal papillae difficult to discern. Hyaline core 5 (3-9) pm long. Intestine. four to six cells in circumference. Rectum 23 (19-29) pm long. - 183 - Male and juvenile Not found. Locality and habitat Present specimens from Cape Province: from soil in a vineyard on the farm "I Arc d' Orleans", Franschhoek , collected by J. Heyns, 30 March 1966; from soil in an apple orchard on the farm "Weltevreden", Grabouw, collected by J. M. Giliomee, July and October 1968. Natal: from soil among the roots of grasses under pine trees at the camping site in Rugged Glen, Mont-aux-Sources, collected by J. Heyns and M. Hutsebaut, 9 September 1988. Specimens Natal specimens on slide RAU 4381 in the nematode collection of the Rand Afrikaans University, Johannesburg; specimens from Cape Province on slides 7310, 7311, 7684, 8070, 8790, 8701, 8788 in the National Collection of Nematodes, Biosystematics Divi sion, Plant Protection Research Institute, Pretoria. Coomansus parvus (de Man, 1880) Jairajpuri & Khan, 1977 Syn. Coomansus parvulus (Coetzee, 1968) Jairajpuri & Khan, 1977 (Figure 5; Table 5) Mononchus parvus (= Coomansus parvus), was first described by de Man (1880) from the Netherlands. Coetzee (1968) described a new species Mononchus parvulus (= Cooman sus parvulus) from Fouriesburg in the Orange Free State. According to her this species appears to be closely related to C. pervus, but differs in the more strongly developed dorsal tooth, which is also situated further forward in the buccal cavity. According to Jairajpuri & Khan (1982), C. parvus shows considerable variation in body measure- - 184 - ments, shape of buccal cavity and tail, amphid position, nature and position of dorsal tooth and in the thickness of the buccal cavity walls. The author is in agreement with the synonymy of C. parvulus with C. parvus, as first suggested by Jairajpuri (1970) and en dorsed by Jairajpuri & Khan (1982). Five females from Transvaal and the Cape, identified as C. pervus, correspond well to previous descriptions of this species. Description Female Cuticle with fine transverse striations, mesocuticle sometimes irregularly separated from rest of cuticle. Lateral field about one quarter to one third of corresponding body width wide. Lateral body pores visible in neck region of one specimen only. No dorsal or ventral pores seen. Lip region slightly offset; papillae distinct. Amphid apertures and fovea indistinct, except in one specimen where it is situated almost at the beginning of the buccal cavity, 8 pm from anterior end. Buccal cavity ovoid, walls 1-2 pm thick, without striations. One pair of geusids opening subventrad into buccal cavity. Oesophagus more strongly muscular in posterior third. Oesophageal gland nuclei indistinct, except dorsal gland nucleus visible in one specimen and nucleus of second pair distinct in another. Outlet of dorsal gland nucleus seen in one specimen, outlets of first and second pair of gland nuclei discernable in all specimens. Nerve ring difficult to see, 105 pm from anterior end in one specimen. Excre tory pore not seen. Vulva a transverse slit with thickened lips. Vagina with scierotized pieces. Ovejector present. Sphincter muscle between uterus and oviduct observed in one specimen. One egg (proximally indented) present in each uterus of one specimen, one egg measuring 31 x - 185 - 99 Jim in anterior uterus of another. Tail conoid, quite strongly arcuate ventrad, with a rounded terminus. Caudal glands and spinneret absent. Caudal papillae comprising one subdorsal and one subventral pair, seen only in one specimen. Hyaline core 4,4 (3-5) Jim long. Intestine four to six cells in circumference. Rectum 21 (18-24) pm long. Male and juvenile Not found. Locality and habitat Present specimens from soil among the roots of shrubs, Menlo Park, Pretoria, in the Transvaal, collected by J. Heyns, 23 September 1971 and from soil at the "Herrie" monument in Meiringspoort, Oudtshoorn in the Cape, collected by K.P.N. Kleynhans, 23 October 1980. Specimens On slides RAU 275 (Pretoria specimens) and 18160 (Oudtshoorn specimens) in the nematode collection of the Rand Afrikaans University and the National Collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria, respect ively. KEY TO THE MONONCHUS BASTIAN, 1865, CLARKUS JAIRAJPURI, 1970 AND COO MANSUS JAIRAJPURI & KHAN, 1977 SPECIES OF SOUTHERN AFRICA 1. Lips well developed; caudal glands and spinneret absent.. 2 Lips poorly developed; caudal glands and spinneret present 5 2. Buccal cavity with a non-denticulate ventral ridge 3 Buccal cavity without a ventral ridge .4 - 186 - 3. Buccal cavity larger (36-43 x 14-20 pm); tail longer (95-143 pm). C/arkus sheri Buccal cavity smaller (24-27 x 9-14 pm); tail shorter (60-83 pm) C/arkus papillatus 4. Body longer (1,6-1,8 mm); buccal cavity larger (33 x 15,2 pm); tail longer (118 pm) Coomansus pretoriensis Body shorter (0,8-1,14 rnm): buccal cavity smaller (23,6-26 x 8,3-12,5 pm); tail shorter (59,7-93 pm) Coomansus parvus 5. Buccal cavity larger (42-49 x14-20 pm); tail more slender Mononchus truncatus Buccal cavity smaller (29-36 x 11-13 pm); tail stout Mononchus aquaticus ACKNOWLEDGEMENTS Thanks are due to Dr. Esther van den Berg for the loan of specimens from the National Collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. Financial support by the Foundation for Research Development of the CSIR is gratefully acknowledged. REFERENCES ANDRaSSY, I. 1958. Ober das System der Mononchiden (Mononchidae Chitwood, 1937; Nematoda). Anna/es Historico-Natura/es Musei Nationa/is Hungarici 50: 157-171. ANDRaSSY, I. 1983. The free-living nematode fauna of the Hortobaqv National Park. Akademiai Kiado, Budapest: 31-46. ANDRaSSY, I. 1985. On the genera Mononchus Bastian, 1865 and Prionchu/us (Cobb, - 187 - 1916) Wu & Hoeppli, 1929 (Nematoda: Mononchidae). Opuscula Zoologica, Budapest 21: 9-21. BASTIAN, H.C. 1865. Monograph of the Anguillulidae, or free nematoids, marine, land, and freshwater; with descriptions of 100 new species. Iienssctions of the Linnean Society of London 25: 73-184. BAQRI, S.Z. & JAIRAJPURI, M.S. 1972. Morphology of Mononchus aquaticus. Indian Journal of Nematology 2: 106-11 6. CHAVES, E. 1990. Mononchida (Nematoda) from Argentina. Nematologica 36: 181-193. CLARK, W.C. 1960. Redescription of Mononchus truncatus Bastian, M. papillatus Bastian and Prionchulus muscorum (Dujardin) (Enoplida, Nematoda). Nematologica 5: 184-198. COETZEE, V. 1968. Southern African species of the genera Mononchus and Prionchulus (Mononchidae). Nematologica 14: 63-76. COOMANS, A. & KHAN, S.H. 1981. Mononchida from Mount Kenya. Biologiese Jaarboek Dodonaea 49: 64-75. DE MAN, J. D. 1880. Die einheimischen, frei in der reinen Erde und im sussen Wasser le bende Nematoden. Tijdschrift der Nederlandsche Dierkundige Vereeniging 5: 1-104. GROOTAERT, P. 1976. A note on the aquatic Nematodes from Rio de Oro (North-Western -Sahara). Bulletin de I'I.F.A.N., E 38, Series A: 832-334. - 188 - GROOTAERT, P. & MAERTENS, D. 1976. Cultivation and life cycle of Mononchus aquati cus. Nematologica 22: 173-181. JAIRAJPURI, M.S. 1970. Studies on Mononchida of India II. The genera Mononchus, Clarkus n.gen. and Prionchulus (family Mononchidae Chitwood, 1937). Nematolo gica 16: 213-221. JAIRAJPURI, M.S. & KHAN, W.U. 1977. Studies on Mononchida of India IX. Further division of the genus Clarkus Jairajpuri, 1970, with proposal of Coomansus n.gen. (family Mononchidae Chitwood, 1937) and descriptions of two new species. Nematologica 23: 89-96. JAIRAJPURI, M.S. & KHAN, W.U. 1982. Predatory Nematodes (MononchidaJ with special reference to India. Associated Publishing Company. New Dehli, India. 129pp. LOOF, P.A.A. 1990. Notes on males in species of the genus Mononchus Bastian, 1865 with a description of the male of M. tunbridgensis Bastian, 1865 (Nematoda; Mononchina). Nematologica 36: 266-272. MULVEY, R.H. 1967. The Mononchidae: A family of predaceous nematodes VI. Genus Mononchus (Nematoda: Mononchidae). Canadian Journal ofZoology 45: 915-940. SMALL, R.W. & GROOTAERT, P. 1977. Description of the male of Mononchus equeticus Coetzee, 1968 (Nematoda: Mononchidae) with observations on the females. 8iolo giese Jaarboek Dodonaea 45: 162-170. WINISZEWSKA, G. 1985. Six species of Mononchoidea (Nematoda) new to the fauna of - 189 - Poland. Fragmenta Faunistica 3: 29-38. ZELL, H. 1985. Nematoden eines Buchenwaldbodens 3. Prionchulus muscorum (Nemato da, Mononchida). Carolinea 42: 57-74. ZULLlNI, A. 1971. Studio sulle variazioni del popolamento nematologicio in un muschio. Estratto dai Rendiconti, Classe di Scienze (B) 105: 69-106. ZULLlNI, A. 1973. Some soil and freshwater nematodes from Chiapas (Mexico). Accede mia Nazionale dei Lincei 370: 55-69. ZULLlNI, A. 1977. Subterranean fauna of Mexico Part III. Accademia Nazionale dei Lincei 374: 88-90. (Published in Phytophylactica 24) - 190- TABLE 1: Morphometric data of two populations of Mononchus aquaticus Coetzee. 1968 .Leslie Windhoek n 12 ~ 14 ¥!:(. L(mm) 1,46(1.31-1.80) 1.90(1,70-2,20) a 37•7(3 1 •4-41 ,1 ) 37.3(34,7-40.7) b 4,6(4.3-5.0) 4.8(4.3-5.3) c 9,2(7.7-10,6) 9,5(8,9-10.3) c' 5,6(4.3-6.7) 5,9(5.0-6,3) ~ 50, 3(49-53) 50.4(48-54) Lip region width .21, 9( 20-24) 24(22-26) .... '''''." ...... _- ....c.c Buccal cavity length 31,1 (30-32) 32,3(29-36) . width 11,5(11-13) 11.5(11-13) Indentation of anterior subventral vertical plate % 29.6(28-31) 28,8(25-34) Nerve ring from anterior end 104,6(98-109) (n=9) 127(115-137) Excreto~1 pore from anterior end 140(127-150) (n=lO) ~ateral field % 37(32-47) 34,8(28-42) iTail length 157.8( 140-180) 201(165-240) Rectum length 24.5( 18-29) 28,4(26-30) (n=12) TABLE 2: !imxDletric data of seYeta1 populatiros of Hxx::o::hJs t:rtn::a0Js Bastian. 1865 mx1 !bxxrhJs bellus 1t:xlr3ssy. 1985 MJncnchus cruncatus Accord1ng to Clark According to Cocmms & Present spe--..i::le1s (1960) & IQ1an (1981) Fa1=uth Qti.ppenham Fa1=uth M:ltmt Kenya Baberton & Parys Botswana Fen Hooo.spruit n Neotype 9.;.t. 2.;.t. Neotype 8++' 3.;.t. 3++. 3+1- 4 jj L(mn) 1.92 1.86(1.65-2.14) 1.67-1.85 - 2.16(1.81-2.39) 2.10(2.05-2.15) .1.83(1.76-1.94) 1.910.66-2.10) 1.41(1.2...."-1.65) .... a 28 33-36 29.7(25.2-35,6 37,6(37.2-38) 35.j(32,4-40,1) 33,5(31.3-36,1) 34.4(32.4-37,5) (.0 26-40 * - f',J b 3,9 3.4-4.3 * 3.6-3,8 - 3,7(3,3-4,1) .3.9(3,6-4,1) 4,0-(4,0-4.1) 3.85(3.6-4.0) 3.7(3.6-3.8) c 8 6.4-8.6 * 5.8-6.4 - 6.3(5.5-6.8) 8.9(8.2...,9.5'> 7.7(7.1-8.1) 8.4(8.1-8.6) 8.0(7.5-8.5) c' - [6.9] - - 8.0(6.8-9.0) 8.0(7.0-9.5) 7.6(7.3-8.0) 6.8(6.6-7.0) 6.7(6.3-8.2) ~ 55.5 48.4-55.5 * 53.4-54.3 - 52(49.5-54) 54-55(0=2) 53.7(53-55) 53(52-54) - Up region width - [27.6] - [29.3) [34.5) 26-27(0=2) 24.7(23-26) 25(2..1..28) - Pllccal cavity length - [45] - (48) [54.5]· . 46.3(44-48) 43(42-45) 47(44-49) (35-35) x width - [14) - [20) [18] 16.7(15-20) 14.3(14-15) 14,7(14-15) llx Subventral ribs % - - - [22] [27] 23-25(0=2) 25,7(24-27) 23,3(22-26) 25.5(:!.-"-26) x Dorsal tooth apex % - 28 - [28) 29.2(27-33) 27.3(26-29) 25.3(21-29) 27.7(27-28) 26.5(:!.-"-29) x lateral field :: - - - - - 25(11=2) 24-33(11=2) 28-31(0=2) - Tail length - [243] - - 346(280-391) 220-251(0=2) .239(234-250) 228(204-250) - [) .. Calculated frOlll the original illustrations *- No average g1Veil X -n-3 o - Probably c:oa:posite figures for all. localities T.\llLE 2: MJepluu:t:ric: data of ~ ~tialS of ~ t::ux:1t1JS Bost::l.:m. 1865 aDd. !i:o:n::hJs ~ 1o:1r5ssy, 198.5 (continued) Mononchus bellus Accord1.ng to Andras:l}' Accord1.ng to Clave:! (1985) (1990) FIleno Rico Argentina thmgar"; Argentina n 11+ * 1 H * 1 +.:;:. * 5';':;:' .... L(m:n) l,S8-i,61 1,54-1,62 1,60-1,79 2,05(1,9-2,2) CD a W 29-34 JO-31 2S-JO 33,4(30,9-35,9) b 3,5-4,0 3,9-4,0 4,0-4,2 4 c 6,1-6,8 6,8-7,0 6,8-3,4 8,7(7,5-10,8) c:' 7,8-8,2 6,7 6-a 6,3(5,3-7,3) v': 54-56 51-53 53-34 54,5(53-56) Up region width (29) - - 26,6(26-28) Euc:::1l c::lvit"; ler'..g""•.h [50) 40 - 47 0 - 46,2(44-49) width [16] 18 - 21 0 - 21,2(19-23) Subvent:al. ribs :: [24] - - [27] I:or~ tooth apex % [28] ::0 - 33 0 - 29,2(26-32) Lat~ fi!Ud :: -- - - !ail length - 220-2580 ,. 235,6(199-258) [)- Calc:ulated frtllll the original illustrations *- ~ average given x -0-3 o - Probably OCIlpO:>ite figures for all.localities TABLE 3: KJr~b ad t Ie data of ~~(MJlvey. 1967) JaiIajpJd.. 1970 aai~.i!2!:!! (Oletzee. 1968) Ja1Iajplrl. 1970 ~~ Present specimens Figgs Peek Ventersdorp. Pretor1a. Blydepoort Newl::astle & Faure.lllli.th PinetO'ioU n 2.f¥. 5¥-¥- 2&5 3¥-¥- 4!i-¥- L(mn) 2.25-2,49 2.1(1.78-2.31) 2.13--2.24 1,81(1.52-1.96) 1,95(1,68-2.20) a 34,0-36.1 27.2(20,9-33.9) 31.8-32.5 28,6(24.1-35,0) 24,5(20.9-25,6) b 4.9-5,1 4,4{3.7-4.8) 4.4-4.8 4.1(4,0-4.3) 4,4(4.2-4.5) '.....''''-.. - ... c 17.4-17.7 17.4(15.5-18.6) 20,4-22.4 16,3(14.9-18.1) 18,4(17.1-19.1) CO <:' 2,7-3.4 2.6(2.4-2.9) 2.0-2.2 2.76(2.7-2.8) 2.3(2.0-2.5) .;. V% 57-61 61(60-63) 0 - 62.7(61-64) 62,5(61-65) Up regular width 33-37 35.6(3Q-40) 39-<0 36.7(33-40) 38.5(38-40) height 10-11 12,8(12-13) 10-11 13.7(13-14) 10(0=3) Buccal. cavity length 40 40,6(38-43) 40-43 39.3(36-43) 38(37-40) width 16 16,9(15-20) 15 15(14-16) 19.3(16-21) Dorsal, tooth apex :: 23 25.6(23-29) 25-26 25(23-27) 25(22-27) ~hid fran anterior end 11(0-1) 13.8(12-16) 10-11 LS(13-16) 10.8(10-13) Nerve ring fran anterior end 145(n=1) lSQ-153(n=2) - - - Lateral field :: 26 (0-1) 25.2(24-27) 26-27 29,7(28-32) 24.3(23-26)(n=3) TaU length 127-143 120.8(110-134) 95-110 1ll.7(96-131) 106 (98-115) Spic:u1Lm 1engt..'t -- 85-94 - - Lateral guiding piece length - - 20-22 - - GJbernacJlum length - - 24 -- SUppleamts - - 14 - - []- Calculated fran the or1g1nal 1llustt3t1 ~~ ~~ According to H.1lvey N.:mrding Accotd.1ng to According to Coetzee (1967) to Zulllni Jairajpuri & Khan (1968) (1977) (1982) California Me:d.co India We.l.Ungton Several localities n llilotype Allotype Paratypes 1m 1 ~ ? ~ .. Iblotype Paratypes 12 :;.:;. 19 ¥¥- L(mn) 1.8 1.8 1,80,6-2,1) 2,10 1,9-3,2 1,7 1,70,5-1,9) 1,6-2,3 a 27 33 28(24-30) 29 23-27 24 27(21-29) 22-30 b 4,2 4,3 4,1(3,9-4,:3) 4,0 3,9-4,6 4 4 4,0-4,4 c 17 22 18(16-21) 21 1q...17 16 16(14-19) 13-19 ... c' [2,4] [3,2] (3,0] .<.c - - - - - ~1 57...f;4 U1 'Co 59 - 60(59-63) 63 61 62 Up regular width - - [JO,8J [38] 32-35 - [34] - height - - [12,1] [12,7J 10-15 - [ 11,2] - Buccal cavity length 35 33 32-38 .. 41 34-38 - [38] - width 20 20 19-23 * - 16-18 - [16] - Dorsal tooth apex :: - - 25-28* [27] 27-30 28 25-30* - hJl>hid from antenor end - - {12,S] - 12-16 - [9,6] - Nerve ring from anterior end - - - - 130-136 - - - Lateral field ~ ------Tail length lOS (90] [ 10S,8] 110 100-110 - - - Spiculu:n length - 80 ------Lateral guiding piece length - [19,3] ------Q.lbernaculu:n lengt..~ - (18,2] ------Supplarents - 10 - - - - - [ ] .. Calculated from the anginal lllustraticns .. .. No average given o .. n > 4 TABlE 4: M:n:polloottic data of C1arloJs papillatlls (Bastinn, 1865) Jai.raPJri, 1970 According to Clark (1960) Present spectmens Broadm:>or MJnt-aux-Scurces Franschhoek GrabaU'.- n Neotype 9~ 1 ¥- 7~ 4!# L(lIID) 1.29 1.23(1.01-1.30) 1.23 1.06(0.96-1,22) 0.96(0.90-1.09) a 29 22-29 * 26.7 24.9(22,3-27.4) 25.1(23.3-27.1) b 3,9 3.6-3,9 * 3.7 3.6(3.4-3.8) 3.60.4-3.8) c 19 14-19 14.6 14.5(12,8-17.7) 15.1(13.8-16.0) .... c' [2.5] 2.9 3,0(2.6-3.6) 2.9(2.8-3.1) (0 - (j) V% 62.2 60.~7.7* 59 62(61-63) 62.8(62-M) Up region width - [26.3] 25 24(22-25) 24.3(22-26) height - [9.2] 9 8.1(8-9) 7.8(7-8) Buccal cavity Iength - [26] 26 24.7(24-27) 24 width - [13] 10 10.6(l}-14) 9.8(l}-10)] Dorsal tooth ape:" r. - 15-21* 15 17(16-19) 17 Lateral field 7- - - 24 24,1(22-30) 23(21-26) Tail length - [93,3] 84 73,9(69-83) 63.8(60-68) [ ] .. Calculated fran the original illustrations * .. No average given TABLE 5: MxpOOretrlc data of Swth African populatioos of QxmmSIJS Jl!lrVUS (de Mm. 1800) Ja:U:ajpuri.& lQIan. 1m PresentspeciJrens Type spec.:imens of Q.. P.2rvulus (g. P.2!'V\.!.':i) according to Coetzee, (1968) Pretoria n 2¥¥ 3¥¥ Holotype Paratype 3¥¥ L(mn) 0,90-0,95 1,05(0,95-1,14) 0,9 0,8 0,86(0,8-0,9) c.o a 22-25 26,6(24,4-28,3) 22 22 21(19-23) '-J b 3,3-3,4 4,0(3,9-4,0) 4 4 4 c 11,5-12,3 12,1(11,7-12,3) 13 14 12 c' 3,3-3,4 3,2(3,1-3,4) [2,8] - [2,4-2,7]* V% 64--f:J7 61(60-62) 63 62 62,3(62-63) Up region widt.'l 22 22,7(22-23) [21] - [20,6-22,2]* height 8 9(7-11) [9,7] - [8,3-9,7]* Buccal cavt ty length 25 25,3(24-26) [25] - [23,6-25]* widt.'l 10-11 9,7(9-10) [12,5] - [8,3-9,7]* Dorsal tooth ape.'< % 32-36 30,3(27-35) .30 37 [24-29]* Lateral field % 29-30 33(26-38) - -- Tail length n-78 87(78-93) [62,S] - [59,7-65,2]* [ ] = Calculated fran the original. illustrations * =n=2 Figure 1: Mononchus aquaticus Coetzee, 1968 A,B and D. Windhoek specimens A. Posterior reproductive branch B. Head region C. Heat-relaxed body postures D. Female tail - 198- A B Figure 2: Mononchus truncatus Bastian, 1865 A-C and E. Botswana specimens A. Head and neck region B. Reproductive system C. Tail terminus D. Head region (Hoedspruit specimen) E. Female tail F. Heat-relaxed body postures - 199 - 1 1 1 1 1 1 1 1 o 1 A 1 c 1 'j 1 I I. 1 I::'.,t 1 r- f:;: 1 t::... r- 1 I:,~ \: 1 1: r-(::::: 1 F ,...... 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 w 1 ci 1 01:0 1 oct U- 1 1 1 1 1 n 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Figure 3: Clarkus sheri (Mulvey, 1967) Jairajpuri, 1970 B,D, F - G. Ventersdorp specimens A. Head and neck region (Pinetown specimen) B. Head region C. Anterior reproductive branch (Newcastle specimen) D. Sperm cells E. Heat-relaxed body postures F. Male posterior region G. Female tail - 200- Figure 4: Clarkus papillatus (Bastian, 1865) Jairajpuri, 1970 A,C,D,F and G. Franschhoek specimens A. Head and neck region B. Head (dorso-ventral view) and neck region (Grabouw specimen) C. Head of another specimen showing slight variation D. Reproductive system E. Heat-relaxed body postures F. Slightly aberrant tail G. Tail - 201 - B E Llmm G Figure 5: Coomansus parvus (de Man, 1880) Jairajpuri & Khan, 1977 A-D. Oudtshoorn specimens A. Head and neck region B. Reproductive system C. Tail D. Head E. Heat-relaxed body postures - 202- c E ,. CHAPTER 'TWO Mononchida (Nematoda) of southern Africa: genus lotonchus (Cobb, 1916) Altherr, 1950 ABSTRACT Descriptions and illustrations of several known species of the genus lotonchus (Cobb, 1916) Altherr, 1950 from South Africa, Botswana and Namibia are given. Species described are: I. acutus (Cobb, 1917) Andrassy, 1958; I. geminus Heyns & Lagerwey, 1965; I. litoralis Coetzee, 1967, I. monhystera (Cobb, 1917) Jairajpuri, 1970; I. parabasidontus Mulvey & Jensen, 1967 and I. rinae Coetzee, 1967. lotonchus shafii Jairajpuri, 1980 is considered a synonym of I. litoralis and lotonchus jairi (Lordello, 1958) Clark, 1960 of Malcevshi, 1981 is considered a synonym of I. monhystera. A single specimen is reported, but not named, which differs from I. parabasidontus only in the absence of caudal glands and spinneret. A new species lotonchus loteniae spec. nov. is also described. An identification key is given for the southern African species. UITTREKSEL Mononchida (Nematoda) vanaf suider Afrika: genus lotonchus (Cobb, 1916) Altherr, 1950 Beskrywings en Iyntekeninge van verskeie bekende spesies van die genus lotonchus (Cobb, 1916) Altherr, 1950 afkomstig van Suid-Afrika, Botswana en Namibie word gegee. Die volgende spesies word beskryf: I. acutus (Cobb, 1917) Andrassy, 1958, I. geminus Heyns & Lagerwey, 1965, I. Iitoralis Coetzee, 1967, I. monhystera (Cobb, 1917) Jairajpuri, 1970, I. parabasidontus Mulvey & Jensen, 1967 en J. rinae Coetzee, 1967. J. shafii Jairajpuri, 1980 word beskou as 'n sinoniem van - 203- I. litoralis en I. jairi (Lordello,1958) Clark, 1960 van Malcevshi, 1981 as 'n sinoniem van I. rnon hystera. Een eksemplaar, wat slegs deur die afwesigheid van koudale kliere en 'n spinneret van I. parabasidontus verskil, word aangemeld, maar nie benaam nie. 'n Nuwe spesie I. loteniae spec. nov. word oak beskryf. 'n Identifikasie sleutel vir die spesies van suider Afrika word gegee. INTRODUCTION Heyns & Lagerwey (1965) were the first authors to report on the Mononchida occurring in southern Africa. They described three new species of the genus lotonchus namely: I. pauli, I. geminus and I. transkeiensis from Bizana and Port St. Johns in the Transkei. Specimens of I.acutus and I. risoceiae were also reported from several localities in South Africa, as well as from Bizana and Zangontshe in the Transkei. Coetzee (1967) added four new species to this genus with the description of I. antedon toides from Transvaal and Natal, I. rinae and I. spinicaudatus from the Cape and I. litoralis from Port St. Johns in the Transkei. Since Coetzee's 1967 publication, numerous specimens of this genus have been collected and deposited in the nematode collection of the Rand Afrikaans University and of the National collection of Nematodes, Biosystematics Division, Plant Protection Research Insti tute, Pretoria. This material formed the basis for this study. MATERIALS AND METHODS Specimens were killed by gentle heat, fixed in FAA and processed into glycerine according to Thorne's slow method and mounted on permanent slides. Measurements and drawings were done with the aid of a Zeiss Standard 18 research microscope, equipped with a drawing tube. Light microscope photographs were taken with a MC63 photomicrographic - 204- camera and differential interference contrast. The body and all curved structures were measured along the median line. Buccal cavity measurements do not include the lip, vesti bule leading into the cavity, the anterior oblique plates or the cavity walls. Cavity width was taken at the broadest part. Measurement of the dorsal tooth apex was taken from the anterior vertical plates and calculated as a percentage of the buccal cavity length. All measurements are in pm unless stated otherwise. TAXONOMY . lotonchus acutus (Cobb, 1917) Andrassy, 1958 Syn. Mononchus acutus Cobb, 1917 (Figure 1 and 2; Table 1) This species was first described by Cobb in 1917 from Virginia, U.S.A., found in loose sandy soil around the roots of rhubarb. After studying Cobb's unpublished illustrations and notes, Mulvey (1963) stated that Cobb had based his description on several juvenile specimens. Mulvey (1963) described and illustrated four female specimens from California which he identified as this species. According to him, the tail shape and tail length of these specimens are similar to that of the unpublished illustrations of the specimens studied by Cobb. He also states that the tail terminus is acutely rounded in the Californian specimens. Heyns & Lagerwey (1965) described females, and for the first time males, from various localities in South Africa and also from Bizana in the Transkei. According to them the South African specimens differ from Mulvey's description of this species in the following: tail four and a half times anal body diameter compared to three and a half times; intestine six or seven cells in circumference compared to about ten cells. The tail shape is similar to that shown in Mulvey's illustration (his Figure 3), except for a more rounded terminus (own observation). - 205- Subsequent to the description by Heyns & Lagerwey, one male and eleven female speci mens, identified as this species, were collected from Natal, Orange Free State and Trans vaal. These are in agreement with previous descriptions and illustrations, except for a slightly smaller b-ratio and buccal cavity in the specimens from Edenville. In the specimens from Barberton, the lip region and buccal cavity appear to be larger, but this is probably due to the flattened condition of the specimens. Description Female and male Cuticle with fine transverse striations; mesocuticle sometimes irregularly separated from rest of cuticle. Amphid aperture 6 (5-7) pm wide, 15 (13-17) pm from anterior end. Fovea cup-shaped. Walls of buccal cavity 2 pm thick, dorsal wall sometimes appearing to be finely striated. Dorsal tooth at base of posterior vertical plate, its apex at 73 (66-79) % of buccal cavity length in present specimens (68-79 % in other specimens - calculated from original illustrations). One pair of geusids present in base of buccal cavity. Oesophageal gland nuclei and outlets inconspicuous. Female Vulva transverse. Advulval papillae comprising one prevulval or one postvulval papilla in some specimens, two prevulval and three postvulval papillae in others; absent in some individuals. Female reproductive branches difficult to discern, but one egg observed in anterior branch, measuring 38 x 122 pm. Tail of female elongate-conoid, tapering gradually towards the terminus, varying from only slightly arcuate ventrad to strongly curved ven trad. Tail terminus acutely pointed to more rounded. Caudal papillae inconspicuous. Coelomocytes present in tail of some specimens. Crystalloids observed in tail region of one female. Hyaline core 11 (4-13) pm long. Intestine six cells in circumference in female, apparently only four in single male specimen available. - 206- Male Agrees with the description by Heyns & Lagerwey (1965), except that ventral pores, excretory pore and ejaculatory glands could not be seen. Sperm cells small, 4 pm in diameter, ovoid. Two pairs of lateral caudal papillae observed. Hyaline core 10 pm long. Remark One female specimen (Figure 2) was found at Cullinan in the Transvaal, which is in close agreement with the morphometrical data of the Californian specimens described by Mulvey (1963) and the male specimen from Cullinan. It differs in having a longer tail, resulting in a bigger c-ratio, larger lip region, longer buccal cavity and longer hyaline core of 18 pm. Juvenile Not found. Locality and habitat The present specimens are from soil among the roots of carrots on the prison grounds in Barberton and from soil next to the gravel road between Cullinan and Groblersdal in the Transvaal, collected by J. Heyns, 16 January 1967 and E. van den Berg, 17 January 1984, respectively; from soil among the roots of Tagetes on the farm "Vandykspruit" Edenville in the Orange Free State, collected by E. van den Berg, 26 February 1982 and from soil next to the footpath near the huts at Giant's Castle Nature Reserve in Natal, collected by E. van den Berg, 2 January 1984. Specimens On slides 7809-7811,8145,18968,19753,20199,21687,21034 and 21958 in the National Collection of Nematodes, Biosystematic Division, Plant Protection Research Insti tute, Pretoria. - 207- lotonchus geminus Heyns & Lagerwey, 1965 (Figures 3 and 4; Table 2) This species was described by Heyns & Lagerwey (1965) from sanddunes overgrown with indigenous plants at Port St. Johns, Transkei. The present material, comprising four females from the Cape and Natal, is in close agreement with the original description, except for a slightly longer body in one specimen, slightly larger a- and b-ratlo and a wider buccal cavity. The larger a-ratio and wider buccal cavity can be ascribed to the specimens being flattened. The holotype and allotype have also become flattened, resulting in a-ratio and buccal cavity dimensions comparable to those of the present specimens. Description Female Cuticle finely striated, with the mesocuticle sometimes irregularly separated from rest of the cuticle. Lateral field not narrow as mentioned by Heyns & Lagerwey, but about one quarter of corresponding body width wide. No lateral, ventral or dorsal pores seen. Amphid aperture 6 (5-7) pm wide, situated 15 (12-18) pm from anterior end. Amphidial fovea seemingly cup-shaped. Walls of buccal cavity 2 pm thick, dorsal wall posteriorly finely striated. Dorsal tooth apex at 76 (74-77) % of buccal cavity length. Heyns & Lagerwey mentioned the presence of a weakly developed advulval pore (papilla) in some specimens. In one of the present specimens, a single postvulval papilla can be seen, whilst in two specimens, a prevulval and postvulval papilla are present. In the fourth specimen, two prevulval plus two postvulval papillae are very distinct. Sclerotized pieces in the vagina are not as square as shown in the original illustration. Muscles in the vaginal region well developed. Caudal glands and caudal papillae present. Intestine eight cells in circumference. - 208- Male and juvenile Not found. Remark Two female specimens with a shorter body, shorter tail and slightly more truncate tail terminus were found at Mont-aux-Sources, Natal and are regarded as a variation of /. geminus. Locality and habitat The present specimens are from soil among the roots of pine trees opposite the plot "Die Toue", Great Brak River and from soil among the roots of pineapples on the farm "New Cobra", Bathurst in the Cape, collected by T. Nortje, 12 October 1965; from soil among the roots of grasses at the steps leading to the waterfall at Oribi Gorge and from soil among the roots of grasses underneath pine trees at the camping site in Rugged Glen, Mont-aux-Sources in Natal, collected by E. van den Berg, 18 November 1981 and J. Heyns and M. Hutsebaut, 9 September 1988, respectively. Specimens On slide RAU 4366 and slides 6409, 7325 and 21336, in the nematode collection of the Department of Zoology, Rand Afrikaans University and the National Collection of Nema todes, Biosystematics Division, Plant Protection Research Institute, Pretoria, respectively. lotonchus litoralis Coetzee, 1967 (Figures 5 and 6; Table 3) Coetzee (1967) described and illustrated two females and two males from Port St. Johns in the Transkei, plus two juveniles and one smaller male from East London, Cape Province - 209- of which the lateral accessory pieces were straighter and more slender, which she regarded as a variation of this species. In her diagnosis, Coetzee stated that I. litoralis closely resembles I. risoceiae (Carvalho, 1955) Andrassy, 1958 but differs in its much shorter tail (I. litoralis: female tail = 202 pm; male tail = 164 pm - calculated from the original illustrations, vs I. risoceiae: female tail = 310-470 pm; male tail = 300-330 pm). Jairajpuri (1969), however, regarded I. litorelis as a synonym of I. risoceiae. The author does not agree with this, considering that I. litoralis is also shorter and has a slightly smal ler buccal cavity. Although I. risoceiae also comprises shorter specimens, ego 2,6 and 2,7 mm (Carvalho, 1955) and 2,7 mm (Khan & Jairajpuri, 1980), the tails are always long, ego 350 and 310pm (Carvalho, 1955) and 310pm (Khan & Jairajpuri, 1980). Kahn & Jairajpuri (1980) described and illustrated a new species, lotonchus shafii from India. They based their description on eight females and ten males, collected from soil among the roots of castor, mango and wild plants in India. In the differential diagnosis, they state that I. shafii comes close to I. basidontus Clark, 1960 and I. parabasidontus Mulvey & Jensen, 1967, but differs from both in the position of its vulva and in having larger spicules. Further differences are a shorter tail, well developed accessory pieces, absence of vulval papillae and a longer gubernaculum. The author considers I. shafii to be much closer to I. litoralis (see Table 3) and regards it as a possible synonym of I. litoralis. The only differences between these two species are a more anterior positioned vulva and slightly shorter tail in I. litoralis. Subsequent to the description of I. litora/is by Coetzee (1967), one female and two male specimens were collected in Natal and identified as this species. They agree closely with the original description and illustrations, except for an even shorter tail, resulting in a bigger c-ratio and larger vulva percentage. - 210 - Description Female and male Cuticle with fine transverse striations, more conspicuous towards tail region where punctations could also be seen. Mesocuticle sometimes irregularly separated from rest of cuticle. Lateral field about one fifth the corresponding body width wide; lateral pores not observed. Dorsal and ventral pores visible just posterior to lip region. Lip region truncate, offset. Buccal cavity ovoid, walls 2 pm thick with striations visible on dorsal wall. Dorsal tooth at base of posterior vertical plate, apex at 72 % of buccal cavity length. Two pairs of geusids opening subventrad into the buccal cavity. Amphid aperture at base of lip region 14 and 16 pm from anterior end (n = 2). Fovea cup-shaped; amphidial canal incon spicuous. Oesophagus as in original description (Coetzee, 1967); encircling muscle bands distinct. Dorsal gland nucleus and outlet conspicuous; subventral gland nuclei not seen, outlets, however, quite distinct. Nerve ring difficult to discern. Excretory pore and duct distinct, 222 pm from anterior end. Female Reproductive system as in original description. Vulva transverse. Vagina difficult to discern, but moderately developed sclerotized pieces present. Vulval muscle bands distinct. One advulval papilla anterior and two posterior to vulva. Ovejector well developed; uterus long, without eggs or sperm cells. Sphincter muscle present between pars dilatata uteri and pars dilatata oviductus. Oviduct short, consisting of a single row of disc-shaped cells. Tail as in original description. Caudal glands not very conspicuous. Intestine ten cells in circumference. Male As in original description except for the following differences. Body curved ventrad when heat-relaxed, with the tail region very strongly curved, almost into a loose spiral in one specimen. Anterior testis 438 and 368 Jim; posterior testis 420 and 416 pm in two - 211 - specimens. Testes containing only spindle-shaped sperm cells in one specimen (Figure 6A). In the second specimen, spindle-shaped sperm cells as well as globular sperm cells are present (Figure 68). A similar situation was described and illustrated in a Paratricho dorus minor specimen by Decraemer & Chaves (1988). Ejaculatory or rectal glands not seen. Supplements tuboid. No ventral indentation of body just anterior to supplements, and ventral pores not observed in this area. Male tail similar to that of female, but shorter. Spicules slender, arcuate, with a partly folded spicular sheath visible in distal region. Caudal glands not clearly visible due to prominent muscle bands. Caudal papillae compris ing one lateral and one subdorsal pair in one specimen, only one subdorsal pair observed in second specimen. Discussion Apart from being close to I. risoceiae, I. litoralis is also similar to lotonchus brachylaimus (Cobb, 1917) Andrassy, 1958 regarding tail shape and tail length. It differs from I. brachylaimus in having a shorter body (I. litoralis = 2,1 - 2,8 mm; I. brachylaimus = 3,2 3,5 rnrn), smaller buccal cavity (I. litoralis = 49-59 x 32-39 Jim; I. brachylaimus = 64 x 53 Jim), longer spicules (I. litoralis 104-131 Jim; I. brachylaimus = 95 Jim) and more anteriorly situated dorsal tooth apex (I. litoralis = 70-73 %; I. brachylaimus = 85 % calculated from the original illustration by Cobb, 1917). Juvenile Not found. Locality and habitat The present specimens are from soil among the roots of natural vegetation at the "Fort Mistake" Hotel on the road between New Castle and Ladysmith in Natal, collected by E. van den Berg, 25 December 1979. - 212 - Specimens On slide 16989 in the National Collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. lotonchus loteniae spec. nov. (Figures 7 and 8; Table 4) Description Female Body curved ventrad when heat-relaxed, especially in posterior part. Cuticle with fine transverse striations; mesocuticle sometimes irregularly separated from rest of cuticle. Lateral field 23 and 17 % of corresponding body width wide in holotype and paratype, respectively (measurements of holotype and paratype always in this order in description); no lateral and dorsal pores visible. Lip region truncate, well set off, 47 and 43 Jim wide, 16 and 18 Jim high; papillae distinct. Amphid aperture ovoid, situated at base of lip region 16 and 18 Jim from anterior end. Fovea and amphidial canal inconspicuous. Buccal cavity ovoid. Posterior oblique plates directed posteriorly into oesophagus in holotype, more anteriorly into the buccal cavity in paratype, resulting in a more rectangular-shaped stoma. Walls 2 Jim thick, dorsal vertical plate finely striated in paratype. Dorsal tooth at base of posterior dorsal vertical plate, apex at 73 and 79 % of buccal cavity length and anteriorly directed. Two pairs of geusids opening subventrad into buccal cavity. Oesophagus cylindroid, anterior portion expanded to enclose base of the stoma. Muscle bands encircling oesophagus distinct in holotype, even more so in paratvpe, Oesophageal gland nuclei indiscernable, except for second subventral pair. All outlets, however, distinct in both specimens. Nerve ring 152 and 151 Jim from anterior end. Excretory pore not seen. Oesophago-intestinal junction tuberculate. - 213 - Reproductive system didelphic, amphidelphic. Two advulval papillae present posterior to vulva in holotype. Vulva transverse. Vagina tuboid, muscular and with moderately deve loped sclerotized pieces. Anterior reproductive branch 262 and 264 pm. Uterus filled with ovoid sperm cells in both specimens. Sphincter muscle between pars dilatata uteri and pars dilatata oviductus inconspicuous. Ovary well developed, 90 and 71 pm long. Poster ior reproductive branch less well developed, 218 and 232 pm long. Sperm cells present in both uterus and pars dilatata oviductus in holotype. Sphincter muscle faintly visible. Ovary short, 40,4 and 44,0 pm long, without distinct oocvtes. Bacteria present in uteri of both specimens. Tail conoid, then elongate-cylindroid, arcuate ventrad, ending in a rounded terminus. Hyaline core short, 3-4 pm. Caudal glands and spinneret absent. One subdorsal and three lateral pairs of caudal papillae present. Intestine six cells in circumfer ence. Rectum 31 and 33 pm long. Male and juvenile Not found. Remark One female (Figure 8) from Pinetown deviates somewhat from the above description. It has a longer hyaline core (13 pm vs 3-4 pm), slightly smaller lips and the posterior oblique plates of the buccal cavity are directed more posteriorly into the oesophagus. Diagnosis lotonchus loteniae spec. nov. can be recognized by the following combination of characters: medium sized with a body length of about 2 mm; vulva position 66-68 %; buccal cavity 30-37 x 25 pm; moderate tail length, 259-275 pm; absence of caudal glands and spinneret; short hyaline core and small posterior ovary. - 214- Relationships lotonchus loteniae spec. nov. differs from all other known species with similar tail shape and didelpic, amphidelphic females, by the small posterior ovary. It further differs from closely related species in the following. From I. basidontus Clark, 1960 in having a smaller buccal cavity (37-38 x 25 pm vs 50 x 25-32 pm); a more posteriorly situated vulva (66-68 % vs 55-63 %) and the absence of caudal glands, spinneret and males. From I. clarki Mulvey & Jensen, 1967 it differs in being more slender (a-ratio = 33,8-41,9 vs 28-34); in having a shorter tail (259-275 pm vs 290-420 pm); a more posteriorly situated vulva (66-68 % vs 52-58 %); smaller buccal cavity (37-38 pm vs 40-43 pm) and a differently shaped tooth (smaller and directed towards the middle of the buccal cavity in I. clarkI). From I. kherai Mohandas & Prabhoo, 1979 it can be distinguished by a shorter body (2,01 2,03 mm vs 3,10-3,41 mm in the female); smaller buccal cavity (37-38 x 25 pm vs 66-75 x 37-40 pm in the female); more posteriorly situated vulva (66-68 % vs 61 %) and absence of caudal glands, spinneret and males. From I. parabasidontus Mulvey & Jensen, 1967 it differs in having a shorter tail (259-275 pm vs 280-340 pm in female); more posteriorly situated vulva (66-68 % vs 56-60 %); smaller buccal cavity (37-38 x 25 pm vs 44-55 x 30-32 pm in the female) and absence of caudal glands, spinneret and males. From I. prabhooi Mohandas, 1979 it differs in the longer body (2,01-2,03 mm vs 1,41 1,72 mm); larger a-ratio (33,8-41,9 vs 2,1-2,8); larger b-ratio (4,3-4,5 vs 3,6-3,9); longer tail (259-275 pm vs 200-250 pm); more posteriorly situated vulva (66-68 % vs 48-60 %); - 215 - differently shaped buccal cavity (narrower and longer in I. prebhooh and absence of caudal glands and spinneret. From I. risoceiae (Carvalho, 1955) Andrassy, 1958 it can be distinguished by a slightly more posteriorly situated vulva (66-68 % vs 42-60 %); smaller buccal cavity (37-38 x 25 pm vs 53-80 x 32-57 pm); shorter tail (259-275 pm vs 310-470 pm) and absence of caudal glands, spinneret and males. From I. stockdilii Yeates, 1987 it differs in a much shorter body (2,01-2,02 mm vs 3,16 6,38 mm); shorter tail (259-275 pm vs 385-850 pm); smaller buccal cavity (37-38 x 25 pm vs 48-95 x 28-70 pm); reflexed ovary (only tip of ovary reflexed in I. stockdilil) and absence of males. From I. tenuidentatus (Kreis, 1924) Mulvey, 1963 it differs in the more posteriorly situated vulva (66-68 % vs 51-58 %); smaller buccal cavity (37-38 x 25 utt: vs 45-52 x 25-40 pm); shorter tail (259-275 pm vs 350-625 pm) and absence of caudal glands and spinneret. Remark The buccal cavity length of the paratype of lotonchus loteniae spec. nov. was not taken into account in the differential diagnosis, because of the abnormal shape. Type locality and habitat Holotype and one paratype female found between the camping site and waterfall in the Loteni Nature Reserve among the roots of grasses and wild flowers, collected by E. van den Berg, 26 December 1978; one paratype female from the Chatsworth area, Pinetown in Natal, colleced by K.P.N. Kleynhans & D.P. Keetch, 16 March 1981 among the roots of grasses. - 216 - Type specimens Holotype female and one paratype female on slide 15486; one paratype female on slide 20650; both slides in the National Collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. lotonchus monhystera (Cobb, 1917) Jairajpuri, 1970 Syn. Mononchus monhystera Cobb, 1917 1 lotonchus antedontoides Coetzee, 1967 (Figure 9; Table 5) Cobb (1917) first described females from Bahia, Brazil. His illustration of the head shows a more or less ovoid buccal cavity, with a small dorsal tooth situated about one third from the anterior end of the buccal cavity. His illustration of the tail end shows an acutely rounded terminus with no spinneret. He mentioned the presence of only one ovary and a forwardly extending vagina, this species thus being monodelphic and prodelphic. In 1970, Jairajpuri identified ten females from Assam, Uttar Pradesh and Himachal Pra desh, India as this species. He compared I. monhystera with lotonchus antedontoides Coetzee, 1967 and remarked that the only possible difference is the presence of a minute tooth-like projection anterior to and opposite the dorsal tooth in I. antedontoides. This tooth-like projection is however also present in some specimens of I. monhystera, but according to Jairajpuri it can be easily overlooked. He therefore regarded I. antedontoides as a synonym of I. monhystera. Khan & Jairajpuri (1980) identified ten females from Kerala, India as I. monhystera, but gave no illustrations. According to them, these specimens also posess a tooth-like projection, which confirms the possible synonymy of I. antedontoides with I. monhystera. - 217 - Although the author is inclined to agree with Jairajpuri (1970) and Khan & Jairajpuri (1980) about the synonymy of I. antedontoides and I. monhystera, it should, however, be pointed out that the presence of a tooth-like projection in the Indian specimens cannot be regarded as proof of this synonymy. To ascertain whether I. monhystera actually posesses a tooth like projection, type material or at least topotypes have to be examined. In fact, without such information, the possibility cannot be ruled out that I. antedontoides is a valid spe cies, and that the Indian specimens actually belong to I.antedontoides rather than to I. monhystera. I. monhystera is morphometrically also very close to I. jairi (Lordello,1958) Clark,1960, described from Brazil, except for a more anteriorly situated dorsal tooth. Malcevshi (1981) identified and described nineteen females and two males from the Ivory Coast as lotonchus jairi. These specimens are in close agreement with the descriptions of I. jairi by Lordello (1958) and of the specimens from Brazil and Nigeria by Mulvey & Jensen (1967), except for a more anteriorly situated dorsal tooth (27 % of buccal cavity length as opposed to 41 %- calculated from the original illustrations of I. jairi by Lordello, 1958). In view of the fact that the dorsal tooth apex in I. monhystera and I. antedontoides is also more anteriorly situated (see Table 5 ), I. jairi of Malcevshi (1981), is possibly a synonym of I. monhystera. Since the type material of I. jairi and I. monhystera were not examined, no formal synonymization can however be made. Five females and one male from the Transvaal and Orange Free State identified as I. monhystera, were available for study. These specimens are in full agreement with the descriptions of I. monhystera as well as with I. antedontoides. Description Female and male Cuticle striations mainly visible in tail region; mesocuticle irregularly separated from rest of - 218 - cuticle. Lateral chord about one third of corresponding body width wide. No body pores visible, except in male, where conspicuous ventral pores are present posterior to the oesophago-intestinal junction up to first supplement. Excretory pore seen just posterior to nerve ring in all specimens. Amphid aperture discernable in all specimens, except one, 4,6 (4-5) pm wide, situated just anterior or posterior to base of lip region 11 (9-12) pm from anterior end. Amphidial canal inconspicuous. Buccal cavity ovoid, walls 1-2 pm thick, fine transverse striations visible in region of dorsal tooth in one specimen. Dorsal tooth situated at 33 (31-35) % of buccal cavity length. No tooth-like projection visible in female speci mens, however, rather distinct in male just anterior to and opposite dorsal tooth. Geusids present. Oesophagus cylindroid. Oesophageal gland nuclei and outlets distinct in all specimens, except the first pair of subventral gland nuclei. Female Vulva transverse; vagina with moderately developed sclerotized pieces. No uterine eggs or sperm cells observed. No distinct pars dilatata uteri and pars dilatata oviductus. Oviduct with disc-like cells. Ovary well developed, with distinct oocvtes. Tail shape similar to those described previously, conoid then curved ventrad, but more strongly curved in some specimens; tail terminus acutely rounded. One lateral pair of caudal papillae, not seen in all specimens. Intestine ten cells in circumference. Rectum 21 and 24 pm long. Male Reproductive system monorchic, testis outstretched. Sperm cells ovoid, 3 pm in diameter. Junction between vas deferens and ductus ejaculatorus opposite second supplement. No ejaculatory glands observed. Supplements papilloid, noncontiguous. Spicules arcuate, with termini bifurcate. Gubernaculum and lateral guiding pieces indiscernible. Tail similar to that of female, but shorter. No rectal glands observed. - 219 - Juvenile Not found. Locality and habitat The present specimens are from soil among the roots of natural vegetation and grasses at the entrance gate on the plot of Mr. M.G. Louw, Pretoria in the Transvaal and from soil among the roots of natural vegetation at the Philippolis turnoff in Fauresmith in the Orange Free State, collected by E. van den Berg, 26 February 1981 and 5 February, 1980, respectively. Specimens On slides 18065, 18311 and 18313 in the National Collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. lotonchus parabasidontus Mulvey & Jensen, 1967 (Figure 10; Table 6) This species was first described by Mulvey & Jensen (1967) from soil among roots of cassava in the Benin province of Nigeria. Khan & Jairajpuri (1980) gave some morphometrical data as well as illustrations of three females, found in soil among roots of banana in Uttar Pradesh, India. Ten females, five males and nineteen juveniles now found in Botswana were identified as this species. They are in close agreement with the original description and illustrations of I. parabasidontus, except for a longer body, larger a- and b ratios and a slightly longer tail in some specimens. Mulvey & Jensen (1967) mentioned the presence of advulval papillae anterior and posterior to the vulva. In the specimens from Botswana, these papillae are either absent, or they vary: one or two prevulval, two prevulval .plus one postvulval, or two prevulval plus two postvulval. In the original description, the spinneret is described as being armed. According to the illustrations of - 220- Khan & Jairajpuri (1980) this is not the case in the specimens from India. In the present specimens the spinneret also seems to be unarmed. Description Female and male Cuticle finely striated; mesocuticle sometimes irregularly separated from rest of cuticle. Lateral pores conspicuous in neck region in three specimens. dorsal and ventral pores not seen except in one specimen. where four ventral pores are present anterior to the vulva and three posterior to the vulva (these are not advulval papillae). Lip region truncate. offset. with distinct papillae. Amphid aperture ovoid. 9 (8-10) pm wide. situated at base of lip region. Fovea cup-shaped; amphidial canal inconspicuous. Buccal cavity ovoid. walls about 3 pm thick and anteriorly finely striated. Geusids present. Dorsal tooth apex at 76 (70-82) % of buccal cavity length. Oesophageal gland nuclei and outlets mostly distinct. One pair of endolids present in oesophageal lumen in one specimen. Excretory pore just posterior to nerve ring. visible in most specimens. Female Reproductive system very distinct. Vulva a pore-like opening. Vagina tuboid, with sclerotized pieces. Uterus well developed. filled with sperm cells in one specimen. Distinct sphincter muscle present between pars dilatata uteri and pars dilatata oviductus. Oviduct short. consisting of a row of disc-shaped cells. Ovaries with distinct oocvtes. No uterine eggs observed. Tail long. conoid. arcuate ventrad, tapering gradually towards the terminus. ending in a spinneret with a small ampulla. Small mucro seen on tail terminus. Caudal glands conspicuous in some specimens. Caudal papillae comprising three lateral. two subdorsal and mostly two subventral pairs. Intestine four cells in circumference. filled with numerous granules. - 221 - Male Reproductive system diorchic, outstretched, consisting of well developed testes 257 (220 291) pm and 266 (190-342) pm filled with rounded sperm cells. Junction between ductus ejaculatorus and vas deferens opposite first supplement. Muscle bands quite distinct in this area. Four well developed ejaculatory glands present. Supplements tuboid, equally developed. Ventral pores visible anterior to first supplement, varying from two to nine. Body indented ventrad just anterior to first supplement. Spicules slender, arcuate with bifurcate termini. Lateral guiding pieces well developed; gubernaculum crescent-shaped. Rectal glands distinct. Male tail similar to that of female, only shorter and stouter. Locality and habitat The present specimens are from soil among the roots of grasses under a solitary palm tree in the northwestern part of the Savuti Marsh in the Chobe National Park and from wet soil among the roots of a sausage tree (Kigelia africana) standing on the edge of the water on Boba Island, Okavango, Botswana, collected by J.Heyns and A. Coomans 27 July 1989 and 1 August 1989, respectively. Specimens On slides RAU 5157,5158,5160,5163,5258,5260-5262 in the nematode collection of the Rand Afrikaans University, Johannesburg. lotonchus Species A (Figure 11) A single female collected under grasses in the veld near Otjikango in Namibia, probably represents a new species closely related to lotonchus parabasidontus, Mulvey & Jensen, 1. 967, differing only in the absence of caudal glands and spinneret. - 222 - Measurements Female (n = 1): L = 3,23 mm, a = 50,4; b = 6,0; c = 9,2; c' = 7,8; V = 61 %; buccal cavity = 56 x 29 pm; tail = 350 pm Brief desription Lip region truncate, offset, 45 pm wide, 16 pm high. Amphid aperture at base of lip region. Buccal cavity ovoid, walls 3 pm thick and anteriorly finely striated. One pair of geusids opening subventrad into buccal cavity. Dorsal tooth apex at 73 % of buccal cavity length. Lateral chord inconspicuous. Ventral and lateral pores visible in neck region. Nerve ring 165 pm from anterior end. Excretory pore not seen. Vulva pore-like. No advulval papillae seen. Reproductive branches distinct; sphincter muscle present between pars dilatata uteri and pars dilatata oviductus. One egg present in anterior oviduct, measur ing 103 x 50 pm. Tail long, conoid, arcuate ventrad, tapering gradually towards a slightly pointed terminus. Caudal glands and spinneret absent. Coelomocytes present, distinct. Caudal papillae comprising two lateral and two subdorsal pairs. Hyaline core 40 pm long. With only one specimen, the author does not consider it advisable to formally name the new species at this stage. Specimen Present specimen on slide 7995 in the National Collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. lotonchus rinae Coetzee, 1967 (Figure12; Table 7) Coetzee (1967) based her description of this species on five females, eleven males and three juveniles collected from cultivated clay-loam soil near East London, Cape Province. - 223- Ten females and eight males from Giant's Castle Nature Reserve in Natal, identified as I. rinse, were available for study. These specimens differ very little from the description and illustrations by Coetzee, except for a slightly shorter gubernaculum which is without visible lateral processes, and a less flattened stoma base. Description Female and male Cuticle with fine transverse striations, especially visible in tail region; mesocuticle sometimes irregularly separated from rest of cuticle. No lateral and dorsal pores visible. One ventral pore seen just anterior to first supplement in male. Amphid aperture situated at base of lip region 6 (5-7) pm from anterior end in males and females. Fovea cup-shaped, amphidial canal inconspicuous. Buccal cavity walls about 2 pm thick. Geusids present. Dorsal tooth apex at 75 (69-81) % and 72 (67-73) % of buccal cavity length in females and males, respectively. Oesophageal gland nuclei indistinct, dorsal nucleus sometimes visible. Outlets of gland cells mostly seen. Excretory pore visible just posterior to nerve ring. Female Similar to the original description. Number of advulval papillae variable: two prevulval plus two postvulval in one specimen, one prevulval plus two postvulval in another, two prevulval plus one postvulval in two specimens, one prevulval plus one postvulval in another two specimens, only one prevulval in one specimen, absent in rest of specimens. Ovoid sperm cells present in uteri of most females. One egg in anterior uterus of one specimen, measuring 97 x 42 ut«. Tail as in original description; one lateral and two subdorsal pairs of caudal papillae seen. Male Similar to the original description. Anterior testis 157 (94-200> pm; posterior testis 196 - 224- (154-242) pi», Body indented ventrad just anterior to first supplement. Spicules slender, arcuate, with partly folded spicular sheath in distal region. Caudal glands mostly inconspicuous; ampulla and spinneret distinct. One subventral and one lateral pair of caudal papillae seen. Locality and habitat The present specimens are from soil among the roots of Plectranthus and ferns next to the "Two Dassie Stream" on the "Forest walk - Cui de Sac" and from soil next to the sidepath just beyond the huts, Giant's Castle Nature Reserve in Natal, collected by E. van den Berg, 2 February 1982. Specimens On slides 18760, 18816, 18845, 18873, 18950, 18951, 18967, 18968, 18970 and 19713 in the National Collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. KEY TO THE IOTONCHUS (COBB, 1916) ALTHERR, 1950 SPECIES OF SOUTHERN AFRICA 1. Female reproductive system monodelphic .I.monhystera Female reproductive system didelphic 2 2. Posterior ovary short .1. loteniae spec. nov. Both ovaries equally developed 3 3. Caudal glands present 4 Caudal glands absent 9 - 225 - 4. Spinneret absent J. spinicaudatus Spinneret present 5 5. Buccal cavity large 42-59 x 22-38 pm 6 Buccal cavity small 28-43 x 16-31 pm 8 6. Spicules short 81-93 pm J. parabasidontus Spicules long 107-111 pm 7 7. Tail short 132-202 pm .l. litoralis Tail long 300-420 pm J. risoceiae 8. Tail slender and more arcuate; edges of lateral guiding pieces curved J. rinae Tail more stout and less arcuate; edges of lateral guiding pieces straight and parallel.. .t. geminus 9. Lateral organs present anterior to vulva .t. transkeiensis No lateral organs present anterior to vulva 9 10. Vulva with sclerotized pieces , .l, acutus Vulva without sclerotized pieces 1. pauli - 226- ACKNOWLEDGEMENTS The author wishes to thank Dr. Esther van den Berg for the loan of specimens from the National Collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. Financial support by the Foundation for Research Development of the CSIR is gratefully acknowledged. REFERENCES CARVALHO, J.C. DE. 1955. Mononchus risoceiae, nova especie (Nematoda, Mononchidae). Revista do Instituto Adolfo Lutz 15: 129-134. COBB, N.A. 1917. The Mononchs (Mononchus Bastian, 1866). A genus of free-living predatory nematodes. Soil Science 3: 431-486. COETZEE, VICTORIA. 1967. Species of the genus lotonchus (Nematoda: Mononchidae) occuring in Southern Africa. Nematologica 13: 367-486. DECRAEMER, W. & CHAVES, E. 1988. Morphology of the reproductive system and structure of sperm cells in some species of the genus Paratrichodorus with uncommon males (Nematoda: Diphtherophorina). Revue de Nematologie 11: 405-409. HEYNS, J. & LAGERWEY, GERDA. 1965. South African species of the genus lotonchus Cobb, 1916 (Nematoda: Mononchidae). South African Journal of Agricultural Science 8: 775-784. JAIRAJPURI, M.S. 1969. Studies on Mononchida of India I. The genera Hadronchus, - 227 - lotonehus and Mieonehus and a revised classification of Mononchida, new order. Nematologiea 15: 557-581. JAIRAJPURI, M.S. 1970. Studies on Mononchida of India II. The genera Mononehus, Clarkus n. gen. and Prionehulus (family Mononchidae Chitwood, 1937). Nematologiea 16: 213-221. KHAN, W.U. & JAIRAJPURI, M.S. 1980. Studies on Mononchida of India XIII. The genus lotonehus (Cobb, 1916) Altherr, 1950 with a key to the species. Nematologiea 26: 1-9. LORDELLO, L.G.E. 1958. Nota sobre ao genero Mononehus de nematodeos predadores. Anais de Eseola Superior de Agricultural Luiz de Oueiroz 14-1 5: 11 9-1 24. MALCEVSHI, S. 1981. Mononchidae of Ivory Coast savannahs: genera lotonehus (Cobb, 1916) and Mieonehus Andrassy, 1958. Nematologia Mediterranea 9: 63-74. MULVEY, R.H. 1963. The Mononchidae: A family of predaceous nematodes IV. Genus lotonehus (Enoplida: Mononchidae). Canadian Journal of Zoology 41: 79-98. MULVEY, R.H. & JENSEN, H.J. 1967. The Mononchidae of Nigeria. Canadian Journal of Zoology 45: 667-727. (Published in Phytophylaetica 24) - 228- TABU 1: Morpho_tric data of Iotonchus ~ (Cobb. 1917) Andrassy. 1958 Barberton CUllinan Edenville Giant's After Heyns & Lagerwey After After Castle (1965) Mulvey Cobb (1963) (1917) n 5,u * 2~ 1 .i- 1 ~ 3~ 1 .i- 10 ~ 10 ~~ 4~ 1 ~ L(mm) 2.18( 2.07-2.31) 1.57-1.72 2.32 2.07 1.78(1.71-1.82) 1.54 2.08( 1. 75-Z.Z3) 1.68( 1.4Z-1.92) Z.0(1.7-Z.4) Z.l a 28.3(26.4-30.8) 29.6-34.4 35.2 37.6 36.1(34.9-36.9) 25.2 34(32-39) 33(Z8-40) 35.8(31.6-40.6) 65.6 a' 48(38.2-55.7) ------b 5.1{5.0-5.3) 4.9-5.2 5.0 -5.2 5.2(5.0-5.3) 4.4 5.6(5.3-6.0) 5.2(4.4-5.5) 4.7(4.4-4.8) 6.6 c 14.1(13.2-15.2) 11.1-12.6 ,10.9 14.9 11.9(11.0-12.9) 11.0 13.6(12.0-15.5) 14.4(13.2-15.6) 14.8(13.8-16.0) - c' 3.2(2,9-3.4) 4,0-4.1 6.2 3.0 4,7(4.3-5.1) 4,7 [4.4] [2.5] [3,8] - V% 66.8(66-68) 65-66 64 - 64.3(63-67) 64 x61-66 - 65(63-66) 44-49 Lip Width 49.8(47-52) 34-38 48 40 34.3(34-35) 40 [39,6] - [39,6] - height 14.8(14-17) 13 17 15 13.3(13-14) 15 [13] - [14] - Buccal cavity length 43,8(41-46) 31-37 46 40 35,7(35-37) 34 fX37-38 - 39-43 x - Width 36.6(35-38) 19-23 20 20. 18.7(18-20) 24 xZ4- 26 .- 20-Z7 x - !'J Nerve ring from !'J anterior 121(n-1) 155 140 122,6(122-123) [ 131] co - - - - - ~teral field % 28.6(19-36) 26-30 29 24 27,7(26-31) 21 - - - - Tail length 154,6(145-162) 137-141 212 139 149.7(141-156) 140 167(159-175) 123(107-141) 134(125-150) - lRectum length 34.8(30-38) 22-26 34 - 27 & 24 26 [23] - - - Spiculum length - - - 82 - - 75(67-83) - - Lateral guiding - piece length - - - 13 - - - [13] - - Gubernaculum length - - - 19 - - - [21] - - Supplements - - - 9 - -- 9-12 - - [ ] - Calculated from the original illustrations * - Specimens flattened x • No average given TABLE 2: Morpho_tdc data of Iotonchus gelllinu8 Reyns & Laget"lley. 1965 Present spec1mens Type :lpec1mens Great Brak River Bathurst Oribi Gorge Mont-aux- After Heyns & Lager~ey (1965) New measurements Sources n 1 !l- I ~ 2n 2n 7-U Holotype Allotype *Holotype *Allotype L(mm) 1,99 2,36 1,70-1,74 1.55-1,67 1.84(1,72-2,08) 1.87 1,86 1,90 1.86 a 29.3 34,2 28,1-28.3 31.0-34,8 27(25-30) 25 29 21,1 22,4 a' 45.7 36,6 - - - - - 35,S 39.5 b 4,7 5.6 4.1-4.4 4.1-4.2 4.1(3.9-4.5) 4,0 '>.4 4,0 4,1 e 15.7 16,5 15.4-16,7 16.5-16.8 13(12,4-14,0) 12,6 15,3 12,7 16.5 c' 2.8 3,1 2,7-3,1 2.8-3,2 - - - 2,9 1,8 /'I.) 'It 66 66 69-70 68-71 66(65-88) 65,5 66 W - - o Lip 1o/1dth 57 44 44-49 37-43 [43] -- 52 48 height 14 14 14 16 [ 18] - - 17 15 Buccal cavity length 41 38 35-39 32-35 38-43 43 39 48 45 width 38 29 29-31 20-23 22-24 24 io 39 34 Nerve ring frolll - - 132 120-140 - - - - - anterior Lateral field % 24 33 26-30 23-26 - - - 24 23 TaU length 127 143 104-110 92-101 134-158 150 121 150 113 Rectum length . 33 40 22 25 [ 22] - - 34 - • Calculated from the original lllu:ltrations * • Specimen:l flattened TABLE 3: Horpho.etric data of Iotonchua litoralis Coetzee. 1967 and Iotonchus shaffi Khan & Jairajpuri. 1960 Pre~ent specimens After Coetzee (1967) After Khan & Jairajpuri (1980) Q 1 .to 2 ~8 Holotype Paratype Allotype Paratype 8H 10 00 L(mm) 2.66 2.59-2.77 2.1 2.3 2.8 2.6 2.3-2.7 2.3-2.64 a 33.7 33.6-35.0 26 24 37 36 27-34 30-37 b 4.1 4.4-4.7 5 5 5 4 4.0-4.6 4.1-4.7 e 15.1 18.4-21.0 10 11 16 16 10-12 10-12 c' 3.6 2.2-2.6 - [4.4J - [2.7] [5.0] [4.0J V% 68 - 62 61 - - 65-70 - Lip width 58 51-52 - [50] - - 47-56 - height - 16-17 - [17J - - 17-24 - Buccal cavity length 54 49 - [59] - - 51-54 - width 39 32-35 - [38J - - 32-36 - Nerve ring from anterior - 62 - - - - - f\,) Lateral field % 19 21-22 - - - - W... Ta11 length 176 132-141 - [202] - [164J 225-300 180-272 Rectum length 3- - -- [20J - Spiculum length - 107-111 - 112 104 - 112-131 Lateral gUiding piece length - 20 - - [ 17] - 18-22 Gubernaculum length - 26-27 - - [24J - 29-33 Supplement::! - 13-14 - 17 1.5 - 12-16 ]• Calculated from the original illustrations TABLE 4: Morphometric data of Iotonchus loteniae spec. nov. Lateni Nature Reserve Pinetown n Holotype Paratype Paratype L(mm) 2,01 2,03 1,94 a 41,9 33,8 40,4 b 4,3 4,5 5,1 c 7,3 7,8 8,6 f',.) c' 9,5 7,4 6,8 w f',.) V% 66 68 61 Lip ~idth 47 43 40 height 16 18 10 Buccal cavity length 37 30 38 ~idth 25 25 22 Nerve ring from anterior 152 151 - Lateral field % 23 17 19 Tail length 275 259 226 Rectum length 31 33 27 TABLE 5: Korpbo.etric data of Iotoocbua DOohyatera (Cobb. 1917) Jairajpuri, 1970 IotoDcbua jairi (Lordello, 1958) Clark, 1960 and Iotoocbua aotedootoidea Coetzee. 1967 1.:. monhystera 1.:. ja1r1 1. antedonto1des Pretoria and Fauresmith After Cobb After Jairajpuri After Khan & After Halcevshi After Coetzee (1917) (1970) Jairajpuri (1980) (1981) ( 1967) Holotype Paratypes n 5U 1 8 1 -?- 10 U * 10 n 19 n 21 00 2g. L(mm) 1.22(1.09-1.36) 1.18 1.0 0.95-t.17 0.8(0.7-0.9) 1.0-1.3 1.1-1.2 1.2 1.2 1.5 a 23.5(22.5-27.2) 27.4 30.5 21-25 30( 28-35) 23-30 31-35 28 32 & 35 b 4.1(3.8-4.3) 3.8 4.1 3.8-4.5 3.4(3.1-3.7) 3.6-4.3 3.6-4.0 4 4 & 4 e 14.4(12.4-15.6) 15.7 - 14-19 16(15-17) 11.6-15.4 13.4-13.9 1~ 10 & 13 c' 2.8(2.5-3.1) 2.0 - [2.6] -- [2.2) - [30) V% 75.4(74-76) 71 79-81 76(73-78) 72-76 76 72 & i6 I'V - - W Lip .,1dth 29(27-31) 28 [21] 21-30 - - [35] - [24J W hll1ght 9(8-10) 10 [5J 7-11 - - [12J - [9) Buccal cavity length 28(25-31) 28 (23) 23-28 - 22-42 29-35 - (24) width 14(13-17) 14 [ 15] 13-15 - 13-24 17-22 - [13] Dorsal tooth apex % 31(31-33) 35 (24) [ 29) - - (27) - [26) 42 X Nerve r1ng from anterior 106(90-116) 107 97 ------Lateral field % 33(28-38) 21 ------Tall length 85(77-91 ) 75 94 53-65 - 79-109 83-92 - (80) Rectum length ------SpicululII length - 62 - 63-64 - - Lateral gUiding piece - - - length - 12 - - - - [8.5) - - Gubernaculum length ------[8) - - Supplements - 7 - - - - [12) - - [I• calculated from the origioal illustrations •• No average given X• calculated by Coet:ell from anterior end of body. as opposed to anterior end of buccal cavity TABU 6: Morpho_cdc data of Iotonchus parabasidontus Mulvey & Jensen. 1967 Botswana After Mulvey & Jensen (1967) After Khan & Jairajpuri ( 1980) Present specimens Type specimen.. 10 ++ 6 .scf 19 jj Holotype Allotype 6++ 3 00 3.f4. L(mm) 3.15(2.75-3.47) 2.98(2.76-3.14) 1.59(1.14-2.68) 22 2.4 2.4(2.2-2.6) 2.2(2.0-2.4) 2,0-3.3* a 49.0{43.7-S2.S) 50.1(45.7-56.0 37.3{30-52) 26 31 31(27-37) 32( 29-38) 30-32* b S.4{S.0-S.8) S.S(S.3-S.6) 4.S(3.7-5. 7) 4.S 4.4 4.5{4.3-4.9) 4. 4( 4. 3-4.7) 4.0-4.3* c 9.6(8.8-10.S) 13.903.0-15.2) 8.2{7.0-10.2) 8 11 8(7.2-8.7) 10(9.1-11.2) S-7 * c' 7.4(6.3-8.8) 4.1(3,6-4,6) 6,1(5.1-7,0) -- [6.9] [4,2] [8,3] V% 63(S9-66) - - S8 - 59(56-60) - 58-60* Lip width 48.5(43-57) 41.S{37-43) - - - [44] [ 42.4] [44] height 1805-20) lS.8(14-18) - - - [15] [12.4] [17.6] Buccal cavity Sl( 48-58) 45( 44-46) SO SO 48-55* 42-50* [50] length - IV Width 27,5(24-31) 2S( 22-27) 29 27 30-32* 25-28* [28] W - .;.. Nerv" ring from anterior 171(161-182) IS0(126-166) ------Lateral field % 19(1S-23 ) 19(16-23) ------Tail length 333( 28S-388) lI4.S( 189-240) - 280 21S 310( 280-340) 220(215-230) [365] Rectum length 36,S(24-40) - -- - [38] - [20] Spiculum length - 89(81-93) - 90 - 90 - Lateral gUiding piece - length - 13(10-16) - - - - [13&17] - Gubernaculum length - 2209-26) - - -- [ 17&21] - Supplement:> - 12(12-13) - - 15 - IS - [ • Calculated from th" original illustrations * • No average given TABLE 7: Morpho_tric data of Iotonchus ~ Coetzee. 1967 . Giant's castle After Coetzee (1967) 10 H 8 ~o Holotype Allotype 4 H paratypes 11 ~o paratypes 3jj L(e) 1.59(1,36-1,89) 1,54(1,25-1,65) 1,8 1,8 1.7(1,5-1.8) 1.8(1.7-1.9) 1,50,5-1,6) a 29,7(26.8-34,5) 33,4(27,8-37.4) 30 38 33(31-38) 37(31-40) 35(30-40) b 4,4(3.9-5.5) 4,4(4,1-5.1) 5 5 5 5 5 e 11,9(9.9-13.3) 15,9(13,7-17.7) 14 15 15(13-16) 18 15 c' 4.3(3,6-5,1) 2.6(2,5-2,8) - - [4,3) [3,5] - V% 65(61-70) - 71 - 7l(68-72) - - Lip width 37,8(32-40) 34,5(31-39) - - [35,3] - - height 14(12-16) 12,9(12-14) - - [16,2] . - - Buccal cavity length 34(29-39) 32,9(28-35) - - [32,4] - - width 21,5(18-24) 18,8(16-23) - - [19,1] - Nerve ring from - anterior 129(n-2) 122(115-131} - - - - - Lateral field % 21,5(l5-25) 22,3(18-27) - -- - - Tail length 133,8(109-157) 96,6(91-106) - - [ 1251 [1221 - (.oJ RectUlll length 27(23-35) '"CJ'l - - - [30] - - Spiculum length 69.7(66-74) - 70 - 63( 60-70) - Lateral guiding piece - length - 10,3(9-12) - - - [8.8] - Gubernaculum length - 16,3(14-18) - - - [11,8] - Supplementll - 9(6-11) - 11 - 11-12 - - calculated from the original illustrations Figure 1: lotonchus acutus (Cobb, 1917) Andrassy, 1958 A and B. Variation in female tail shape C. Head region D. Male tail region E. Vulva region with advulval papillae F. Heat-relaxed body postures - 236- A 8 F cf Figure 2: lotonchus acutus (Cobb, 1917) Andrassy, 1958 Cullinan specimen A. Female tail B. Head region C. Heat-relaxed body posture - 237- 1 1 1 1 B 1 1 1 1 c 1 ) ,I tI 1 ",I .,II " 1 "II "II 1 " "It " "\I It 1 1\ " " 1 "I' II".. II 1 II~Il ~":}':':~ ~ , ••••••• )1 •••••I 1 !'i;~:\~\14\~ii'~: 1 U)\~" \\ Q"<; 1 1 1 1 u mm 1 1 1 1 1 1 1 1 1 1 1 1 I Figure 3: lotonchus geminus Heyns & Lagerwey, 1965 A. Head region B. Female tail C. Anterior branch of female reproductive system D. Heat-relaxed body posture E. Tail terminus - 238- A j j c j D j j j j j j j j j j j j B j j j j j j j j j j j E j j j j j j j j j j j j j j j j j j j j j j j J Figure 4: lotonchus geminus Heyns & Lagerwey, 1965 Mont-aux-Sources specimens A. Female tail region B. Anterior branch of female reproductive system C. Head region D. Heat-relaxed body postures E. Tail terminus - 239- 1 1 1 1 1 1 1 A B c 1 1 1 1 1 1 1 1 o 1 1XI 1 < W 0 1 1 1 1 1 1 1 1 1 1 1 f I 1 I I 1 I I 1 o / 1 1 /j~)1J:;! 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Figure 5: lotonchus litoralis Coetzee, 1967 A. Female tail region B. Posterior branch of female reproductive system C. Head region D. Male tail region E. Heat-relaxed body postures - 240- A 8 c o E UOO:um I 50:um Umm I 50:u I A,D Figure 6: lotonchus Iitoralis Coetzee, 1967 A . Posterior testis (first specimen) B. Poste rior testis (second specimen) - 241 - A B I 85.um A Figure 7: lotonchus loteniae spec. nov. A. Head region B. Female reproductive system C. Head and neck region D. Heat-relaxed body postures E. Female tail - 242- A B c o ~=",",- I 50,um -.Jl A i_=------1.nnm 0 I ~='-'-___scorn I E 1500m a,e Figure 8: lotonchus loteniae spec. nov. Pinetown specimen A. Reproductive system 8. Head region C. Tail D. Heat-relaxed body posture - 243- A B c D fA '0 Figure 9: lotonchus monhystera (Cobb, 1917) Jairajpuri, 1970 A. Female reproductive system B. Male head region C. Female head region D. Female tail E. Male tail region F. Variation in female tail shape G. Heat-relaxed body postures - 244- c A B G 1100..m IA ! SO.. m IB ! as..m I C,D,E,F l1mm IG Figure 10: lotonchus parabasidontus Mulvey & Jensen, 1967 A. Head region B. Endolids in lumen of oesophagus C. Female tail D. Head and neck region E. Posterior branch of female reproductive system F. Ventral view of vulva region G. Tail terminus H. Heat-relaxed body postures I. Male tail region - 245- o B c F H Figure 11: lotonchus species A A. Tail B. Dorsa-ventral view of head region C. Heat-relaxed specimen - 246- A 150(,lm Figure 12: lotonchus rinae Coetzee, 1967 A. Posterior branch of female reproductive system Band C. Head region, showing variation D. Female tail E. Male tail region F. Heat-relaxed body postures - 247- A B c o E F fA E CHAPTER THREE ( Mononchidae (Nematoda) of southern Africa: genera Mylonchulus (Cobb, 1916) Altherr, 1953 and Granonchulus Andrassy, 1958 ABSTRACT Descriptions and illustrations are given for Mylonchulus lacustris (Cobb, N.A. in Cobb, M.V., 1915) Andrassy, 1958; Mylonchulus minor (Cobb, 1893) Andrassy 1958; Mylonchulus sigmaturus (Cobb, 1917) Altherr, 1953 and Granonchulus subdecurrens Coetzee,1966. Mylonchulus hawaiiensis (Cassidy, 1931) Andrassy, 1958 is considered a synonym of M. minor. Females of Mylonchulus agriculturae Coetzee, 1966 (7 synonym of Mylonchulus brachyuris (Butschli, 1873) Altherr, 1953) are also described. A single specimen of Mylonchulus incurvus (Cobb, 1917) Andrassy, 1958, two specimens of Mylonchulus brevicaudatus (Cobb, 1917) Altherr, 1954 and one male specimen of Mylonchulus striatus (Thorne, 1924) Andrassy, 1958 are reported for the first time from southern Africa and briefly described. Mylonchulus species A, Mylonchulus species Band Mylonchulus species C are reported, briefly described but not named. Species A is close to Mylonchulus sigmaturus, species B to Mylonchulus subterraneus (Schneider, 1940) Andrassy, 1958 and species C to Mylonchulus cereris Coetzee, 1966. An identification key is given for the southern African species of Mylonchulus and Granonchulus. UITTREKSEL Mononchida (Nematoda) vanaf suider Afrika: genera Mylonchulus (Cobb, 1916) Andrassy, 1958 en Granonchulus Andrassy, 1958 Beskrywings en Iyntekeninge van Mylonchulus lacustris (Cobb, N.A. in Cobb, M. v., 1915) Andrassy, 1958, Mylonchulus minor (Cobb, 1893) Andrassy, 1958, Mylonchulus sigmaturus (Cobb, - 248- 1917) Altherr, 1953 en Granonchulus subdecurrens Coetzee, 1966 word gegee. Mylonchulus hawaiiensis (Cassidy, 1931) Andressv; 1958 word beskou as 'n moontlike sinoniem van M. minor. Wyfies van Mylonchulus agriculturae Coetzee, 1966 (1 sinoniem van Mylonchulus brachyuris (Butschli, 1873) Altherr, 1953) word ook beskryf. 'n Enkele eksemplaar van Mylonchulus incurvus, (Cobb, 1917) Andressv; 1958, twee eksemplare van Mylonchulus brevicaudatus (Cobb, 1917) Altherr, 1954 en een manlike eksemplaar van Mylonchulus striatus (Thorne, 1924) Andrsssv; 1958 word vir die eerste keer uit suider Afrika aangemeld en kortliks beskryf. Mylonchulus spesie A, Mylonchulus spesie B en Mylonchulus spesie C word aangemeld en kortllks beskryf, maar nie benaam nie. Spesie A is naverwant aan Mylonchulus sigmaturus, spesie B aan Mylonchulus subter raneus (Schneider, 1940) Andrsssv: 1958 en spesie C aan Mylonchulus cereris. 'n Identifikasie sleutel vir Mylonchulus en Granonchulus spesies van suider Afrika word gegee. INTRODUCTION Victoria Coetzee was the first to describe Mylonchulus and Granonchulus species occur ring in southern Africa. Coetzee (1966a) reported My)onchulus species from several loca lities viz. M. lacustris from the Cape, Orange Free State, Transvaal, Natal and Namibia; M. montanus (= M. lacustris) from the Cape and Transvaal and M. sigmaturus from the Cape, Transvaal, Natal and Transkei. Two new species were also described namely: M. cereris from Ceres, Cape and M. agriculturae from the Cape, Orange Free State, Transvaal and Natal. Coetzee (1966b) reported Granonchulus decurrens (Cobb, 1917) Andrassy, 1958 for the first time from the Transvaal and also described a new species Granonchulus subdecurrens, also from the Transvaal. Since the publications of Coetzee, further specimens of Mylonchulus and Granonchulus have been collected and deposited in the nematode collections of the Rand Afrikaans University and of the National collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. This material formed the basis for this study. - 249- MATERIALS AND METHODS Specimens were killed by gentle heat, fixed in FAA and processed into glycerine by Thorne's slow method and mounted on permanent slides. Measurements and drawings were done with the aid of a Zeiss standard 18 research microscope, equipped with a drawing tube. The body and all curved structures were measured along the median line. Buccal cavity measurements do not include the lip, vestibule leading into the cavity, the anterior oblique plates, or the cavity walls. Cavity width was taken at the level of the dorsal tooth apex. Thickness of the cavity walls was measured at the level of the dorsal tooth. Measurement of the tooth apex was taken from the anterior vertical plates and calculated as a percentage of the buccal cavity length. All measurements are in pm unless stated otherwise. TAXONOMY Mylonchulus lacustris (Cobb, N.A. in Cobb, M.V., 1915) Andrassy, 1958; Mylonchulus minor (Cobb, 1893) Andrassy, 1958; Mylonchulus hawaiiensis (Cassidy, 1931) Andrassy 1958 and Mylonchulus sigmaturus (Cobb, 1917) Altherr, 1953 are four closely related species with similar morphometries. In all four species, the spinneret is terminally situated. Since there has been some confusion and uncertainty about the identity of these species, the situation of each will be discussed before proceeding with the descriptions. Mylonchulus lacustris Syn: Mylonchulus montanus (Thorne, 1924) Andrassy, 1958 (Table 1) This species was first described, but not illustrated, by N.A. Cobb in M.V. Cobb (1915), - 250- from Douglas Lake, Michigan, U.S.A. Cobb (1917) identified and described specimens of M. lacustris from Michigan, Panama and Florida. Illustrations were given of a female head and tail terminus. Mulvey & Jensen (1967) examined and redrew Cobb's original, unpu blished illustrations of his 1917 paper (on it Cobb wrote: specimen from Douglas Lake, Michigan). According to these illustrations the buccal cavity is quite large and the lips fairly wide. The tail is about three times the anal body diameter, slightly arcuate ventrad, almost cylindroid in the anterior two-thirds and tapering only slightly towards the rounded tail terminus. The caudal glands are large, their ducts ending in a terminal spinneret. The anal region is not unduly raised. Mulvey & Jensen (1967) remarked that the measure ments of these illustrations correspond better to the measurements of M. lacustris given by Cobb (1915) than with those given in the 1917 paper. They further reported that the specimens described by Cobb (1917) from Michigan and Florida, undoubtedly belong to M. lacustris, but those from Panama probably belong to Mylonchulus minor (see Table 3, p 712 of Mulvey & Jensen, 1967). They apparently had Cobb's unpublished notes on the Florida and Panama specimens as well. The author tends to agree with this, except for one female from Panama which is still regarded as M. lacustris (see Table 1). Thorne (1924) based his description of Mononchus montanus on specimens from Utah, U.S.A. Mulvey & Jensen (1967) reported that this species closely resembles Mylonchulus lacustris, except for minor variation in the tail terminus. They therefore placed M. montanus in synonymy with M. lacustris, with which the author tends to agree. Mylonchulus minor (Table 2) For list of synonyms, see Mulvey (1967) Cobb (1893) first described and illustrated an immature female of M. minor from Fiji. - 251 - According to the illustration, the tail is about one and a half times the anal body diameter, rather stout, arcuate ventrad and with a rounded terminus. The illustration of the head shows a wide buccal cavity, more or less one and a half times as large as wide (no scale was given). Cobb (1917) redescribed this species and remarked that the conoid tail is quite strongly arcuate ventrad and bent somewhat near the middle. According to him, the anus is also slightly raised, with the anterior lip more pronounced than the posterior lip. Mulvey & Jensen (1967) examined Cobb's unpublished illustrations of specimens from Panama, as well as from Breterzorg, Java which Cobb identified as M. minor. According to the unpublished illustrations of a specimen from Panama, the tail is rather stout, arcuate ventrad and with a truncate tail terminus. The anal region does, however, not have a raised appearance. (see Figure 99, p 714 of Mulvey & Jensen, 1967). The buccal cavity of these specimens is one to one and a half times as long as wide (Mulvey & Jensen 1967). Mulvey & Jensen (1967) identified female specimens from Nigeria as M. minor, reporting that they differ from those described by Cobb (1893) in buccal cavity proportions (narrower in the Nigerian specimens). M. minor seems to be a cosmopolitan species and has been described and illustrated by various authors (see Table 2). It is evident from all these descriptions, that the tail shows a considerable variation in shape. In some specimens the conoid tail is only slightly and gradually arcuate ventrad (see Figure 10 and 16B of Jairajpuri, 1970 and Jairajpuri & Khan, 1982, respectively). In other specimens, it is a little indented immediately posterior to the anus, resulting in the anal region having a raised appearance (see Figure 15 of Williams, 1958; Figure 29 of Mulvey, 1961 and Figure 99 and 100 of Mulvey & Jensen, 1967). The tail terminus also varies from more rounded or truncate, to slightly oblique. - 252- Mylonchulus hawaiiensis (Table 3) Cassidy (1931) first described and illustrated female specimens of this species from Oahu, Hawaii. His illustration shows an arcuate and ventrad acutely bent tail, with a rounded terminus. The anal region is quite raised. The buccal cavity is more or less goblet-shaped. Coetzee (1966a) reported specimens of M. lacustris from various localities in South Africa, and mentioned that variation in tail shape occurred in specimens of the same population. Coetzee (1968) however considered these specimens to be close to M. hawaiiensis. M. hawaiiensis has also been reported from India by Jairajpuri (1970), Khan & Jairajpuri (1979), Patil & Khan (1982) and by Jairajpuri & Khan (1982). Further reports were by Mulvey & Jensen (1967) from Nigeria, Mohandas (1972) from Kerala, Baqri & Jairajpuri (1973) from EI Salvador and by Chaves (1990) from Argentina. According to the descriptions and illustrations of M. hawaiiensis, it is clear that the same variation in tail shape exists in this species as in M. minor. According to Figure 16F of Jairajpuri & Khan (1982), the tail is only slightly arcuate ventrad, the tail terminus is more oblique and the anal region is not unduly raised. Opposed to this, Figure 2C of Jairajpuri (1970) shows the tail to be quite strongly arcuate ventrad, with the tail terminus unmistakably rounded and with the anal region rather raised. Comparison of the morphometric data of M. minor and M. hawaiiensis (see Table 2 and 3), shows a continuous variation. According to descriptions as well as illustrations, these two species also appear to be morphologically the same. The author therefore suspects M. beweliensis to be a synonym of M. minor, but refrains from formally proposing such synonymy, since the type material of these two species have not been studied. - 253- Mylonchulus sigmaturus (Table 7) This species was first described by Cobb (1917) from the United States and from Mexico. He remarked that M. sigmaturus resembles M. minor and M. brachyuris. Although the morphometric data of these three species correspond well, M. sigmaturus can quite easily be distinguished from the other two species by its characteristic tail shape (conoid, then abruptly cylindroid, resulting in a short digitate part set off from the rest of the tail by a depression). M. sigmaturus further differs from M. brachyuris in having a terminal spinneret (subterminal in M. brachyuris). M. sigmaturus is a cosmopolitan species, described or reported from various parts of the United States, from Mexico, Hawaii, Italy, Australia, the Netherlands, Germany and Canada (Mulvey, 1961). Further reports were from New Zealand (Clark, 1963), South Africa Coetzee, (1966a & 1968), India ( Khan & Jairajpuri, 1979 and Jairajpuri & Khan, 1982), Brazil (Lordello, 1970) and from Argentina (Chaves,1990). Discussion Although M. lacustris, M. minor and M. sigmaturus are morphometrically very similar, they can be distinguished from each other as follows : M. lacustris has a longer tail that is almost cylindroid and with the anal region not raised. M. minor ( ? = M. hawaiiensis) is characterized by a shorter, stouter tail, varying in shape viz. only slightly arcuate ventrad to more strongly arcuate ventrad and with the tail terminus rounded or truncate, to more oblique. The anal region also varies from slightly to more strongly raised. M. sigmaturus has a short, characteristic tail with a short digitate part set off from the rest of the tail by a depression. - 254- Another group of closely related species with similar morphometries which caused some confusion in the literature, are Mylonchulus brachyuris (BOtschli, 1873) Altherr, 1953; Mylonchulus parabrachyurus (Thorne, 1924) Andrassy, 1958 and Mylonchulus agriculturae Coetzee, 1966. In this group of species the spinneret is subterminal. Mylonchulus brachyuris (Table 8) This species was first described and illustrated by BOtschli (1873). No measurements were, however, given. His illustration of the tail shows a distinct subterminal spinneret, but the arrangement of the caudal glands are not apparent. According to later descriptions and illustrations, the caudal glands are in tandem. Chaves (1990) however stated that the caudal glands in the Argentinian specimens are grouped. Popovici (1990) reported specimens from Romania also with grouped caudal glands, although the illustration of the male tail shows the glands to be in tandem. De Man (1876) described the first male of this species, reporting and illustrating the presence of bifurcated lateral guiding pieces. His illustration shows no caudal glands or a spinneret. Goodey (1942) also described males with bifurcated lateral guiding pieces. Mulvey (1961) stated that these males probably belong to Mylonchulus sigmaturus. This is unlikely, since the tail shape of de Man's male is not typical of that of M. sigmaturus. Mulvey (1961) examined several males of M. brachyuris from Canada, as well as one male from Holland and observed no lateral guiding pieces (his lateral accessory pieces). According to the illustration of the male tail, a distinct bifurcated gubernaculum is present (the latter is also evident in the illustration of the male tail in Mulvey & Jensen, 1967). Although a conspicuous subterminal spinneret is present, no caudal glands are shown in these illustrations. - 255- Jairajpuri & Khan (1982) described males from India, reporting that lateral guiding pieces are absent. According to their illustration of the male tail, the gubernaculum is not bifurcate, and the caudal glands are grouped (in tandem according to the illustration of the female tail). Mylonchulus parabrachyurus (Table 9) Thorne (1924) gave a fairly comprehensive description with illustrations of this species from Utah, U.S.A. According to him, M. parabrachyurus closely resembles M. brachyuris, from which it can be distinguished by the longer tail and tandem caudal glands. The caudal glands in some M. brachyuris specimens are however also arranged in tandem (see Table 8). Thorne (1924) did not report or illustrate lateral guiding pieces, but described the gubernaculum (his lateral accessory pieces) as slender and tapering at both ends. Mulvey (1961) identified males from Canada as M. parabrachyurus but gave no illustrations. According to him slender non-bifurcated lateral guiding pieces (his accessory pieces) are present. Despite the confusion regarding the presence or absence of lateral guiding pieces or arrangement of the caudal glands, M. parabrachyurus can be distinguished from M. brachyuris by the longer tail (60-61 pm in female; 63,3-75 pm in male, vs 26-46 pm in females; 30-38 pm in males in M. brechvuris), Mylonchulus agriculturae (Table 8) Coetzee (1966a) described one male and several female specimens of this species from - 256- various localities in South Africa. According to her, M. agriculturae resembles M. parabra chyurus, but differs from it by the presence of bifurcated lateral guiding pieces. The author considers M. agriculturae to be nearer to M. brachyuris because of its shorter tail (38 and 36 pm in female and male, respectively in M. agriculturae = calculated from the original illustrations; 24-46 and 30-38 pm in females and males, respectively in M. bra chyuris; 60-61 and 63,2-75 pm in females and males, respectively in M. parabrachyurus). The first male of M. brachyuris (described by de Man} 1876) also had bifurcated lateral guiding pieces. Remarks In view of similar morphometric data as well as morphological features of M. brachyuris, M. parabrachyurus and M. agriculturae, it is rather difficult to identify them with certainty. M. parabrachyurus can probably be recognised by the longer tail. The author suspects that M. agriculturae may be a synonym of M. brachyuris. Confusion also exists concerning the lateral guiding pieces (presence or absence) and shape of the gubernaculum of the males of these species. This will only be resolved if type material or at least topotypes can be examined. DESCRIPTIONS Mylonchulus lacustris (Cobb, N.A. in Cobb, M.V., 1915) Andrassy, 1958 (Figure 1; Table 1) Five females were collected from 5etlagole, Volksrust, Edenville, Ladybrand and Fauresmith. These are in full agreement with other descriptions of this species. - 257- Female Cuticle finely striated; lateral field 25 (20-31) % of corresponding body width wide. Dorsal and ventral body pores conspicuous in neck region, lateral pores seen only in one specimen. Lip region slightly offset; papillae distinct. Amphid aperture small, 3,8 (3-4) pm, situated at beginning of buccal cavity in specimen from Fauresmith, about at level of the dorsal tooth apex in other specimens. Fovea cup-shaped; amphidial canal and fusus with sensilla inconspicuous. Buccal cavity more or less goblet-shaped, walls about 3 pm thick, prominently striated. One pair of geusids opening subventrad into buccal cavity. Dorsal tooth relatively large, opposed by two well developed submedian teeth. Subventral denticles arranged in six to nine rows. Oesophageal gland outlets distinct in all specimens, gland nuclei mostly inconspicuous except dorsal gland nucleus. Nerve ring encircling oesophagus at 130 (113-143) pm from anterior end. No excretory pore could be seen. Vulva transverse with sclerotized lips. Vagina with sci erotized pieces. Reproductive branches not very distinct; sphincter muscle not observed. Ovaries with numerous oocvtes discernible in specimen from Ladybrand. Tail conoid, almost cylindrical in anterior two thirds, arcuate ventrad (more so in specimens from Edenville and Fauresmith) with a truncate terminus. Caudal glands in tandem, large, ending in a conspicuous ampulla. Spinneret terminal. Caudal papillae indistinct, except in specimen from Edenville where one subventral pair and two lateral pairs could be seen. Intestine six to eight cells in circumference, filled with numerous yellow granules. Rectum 33 (24-39) pm long. Anal region not raised. Male and juvenile Not found. Locality and habitat Present specimens from Setlagole in the Cape Province (exact locality unknown), collected - 258- by E. van Wyk, March 1978; from soil among the roots of litchis on the farm "Dieprif", Volksrust in Natal, collected by C.H. Hendriks, October 1978; from soil among the roots of grasses and natural vegetation on the farm "China" 10 Km from Edenville; from soil under a willow tree at the Caledon riverbank at the Maseru bridge, Ladybrand and from soil among the roots of natural vegetation at the junction of the Petrusburg and Koffiefontein road just outside Fauresmith in the Orange Free State, collected by K.P.N. Kleynhans, October 1981 and E. van den Berg, March 1981 and February 1980, respectively. Specimens On slides 8352, 11040, 15401, 19739 and 21384 in the National collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. Mylonchulus minor (Cobb, 1893) Andrassy, 1958 ? Syn. M.hawaiiensis (Cassidy, 1931) Andrassy, 1958 (Figures 2 and 3; Tables 2,4,5,6) Females were found at several localities in South Africa, one in Namibia and three in Botswana. Their morphometries are similar to those given in previous descriptions of Mylonchulus minor and of M. hawaiiensis. The same variation in tail shape reported in specimens of M. minor and M. hawaiiensis, occur in the present specimens. Female Cuticle finely striated, striations however not visible in all specimens. Lateral field 26 (24-34) % of corresponding body width wide ; body pores inconspicuous except lateral pores seen in neck region of two specimens. Lip region slightly offset and well developed; papillae distinct. Amphid aperture small, about 4 pm, situated at level of dorsal tooth apex, or either anterior or posterior to this level. Fovea cup-shaped; fusus and sensilla inconspicuous. Buccal cavity goblet-shaped, varying in size in different populations, walls - 259- about 2 pm thick, posterior striations distinct in some specimens, barely visible in others, indistinct in a few. One pair of geusids opening subventrad into buccal cavity. Dorsal tooth large, opposed by two submedian teeth. A small denticle is present in dorsal wall just anterior to dorsal tooth apex. Subventral denticles arranged in five to seven rows. Oeso phageal gland outlets and dorsal gland nucleus distinct in all specimens, other nuclei ob served in some specimens. Nerve ring 105 (90-112) pm from anterior end. One pair of endolids present in lumen of one specimen. Excretory pore seen in specimen from Komati poort, Fauresmith, Verulam, Umhlanga and in one specimen from the Augrabies. Vulva transverse, with unsclerotized lips. Vagina with sclerotized pieces, inner parts of pieces more prominently scierotized in specimens from Hhluhluwe. Reproductive branches short; no eggs or sperm cells present. Sphincter muscle not seen. Ovaries well developed with numerous oocvtes. Tail short, conoid and arcuate ventrad (more so in some specimens). Tail terminus varying from truncate (Figure 38 and D), to more oblique (Figure 3A and C). Caudal glands in tandem (except in one specimen from Okavango), big in specimens from Hhluhluwe (Fig 3A and B) and ending in a terminal spinneret. Caudal papil lae mostly inconspicuous, but two lateral pairs seen in some specimens. Intestine four to six cells in circumference, cells larger in specimens form the Augrabies and the Okavango. Rectum 20 (15-30) pm long. Anal region sometimes raised, mainly in section posterior to anus. Male and juvenile Not found. For locality, habitat and specimens, see Table 5. - 260- Mylonchulus sigmaturus (Cobb, 1917) Altherr, 1953 (Figure 4; Table 7) Females were collected from Pretoria, Barkly East, Lady Grey, Bonnievale, Viljoenskroon, Pietermaritzburg and from the Okavango. These specimens agree well with previous descriptions of M. sigmaturus. Cobb (1917), who first described this species, did not mention or illustrate the arrangement of the caudal glands. According to his original unpublished, illustration of the tail (Figure 106 in Mulvey & Jensen, 1967), the glands appear to be in tandem. This is also the case in the present specimens, although Mulvey (1961), Mulvey & Jensen (1967) and Jensen & Mulvey (1968) also reported Canadian specimens with glands arranged in a group. Jensen & Mulvey (1968) mentioned the presence of prevulval and postvulval papillae. These are absent in the present specimens, except in the Pretoria specimen, where one prevulval papilla could be seen. Female Cuticle with fine striations. Lateral field 30 (22-34) % of corresponding body width wide; body pores inconspicuous. Lip region slightly offset; papillae very distinct. Amphid aperture 4 (3-5) pm wide, situated at level of dorsal tooth apex in specimens from Barkly East, Bonnievale, Viljoenskroon and Okavango, about at the middle of the dorsal tooth in other specimens. Fovea cup-shaped; amphidial canal and fusus inconspicuous. Buccal cavity goblet-shaped, walls about 2 pm thick, posteriorly finely striated. Dorsal tooth large, opposed by two submedian teeth. A small denticle is present in dorsal wall, just anterior to dorsal tooth apex. Subventral denticles arranged in five to six rows. Oesophageal gland outlets distinct in all specimens, gland nuclei, however, indistinct except dorsal gland nucleus and one nucleus of first subventral pair seen in specimen from Pretoria and Viljoenskroon. One pair of endolids present in lumen of oesophagus in specimen from Pietermaritzburg. Nerve ring 105 (96-117) pm from anterior end. Excretory pore conspicuous in specimens from Barkly East, Lady Grey and Pietermaritzburg. - 261 - Vulva transverse with scierotized lips. Vagina with sclerotized pieces. Reproductive branches obscure; no sperm cells present. One egg present in posterior uterus of specimen from Bonnievale, measuring 53 x 100 pm. No sphincter muscle observed at uterus-oviduct junction. Tail short, conoid-arcuate, with short digitate part set off from the rest of the tail. In the specimen from Viljoenskroon, the digitate part is less well set off from the remainder (according to the illustration of the tail by Lordello, 1970, this is also the case in the Brazilian specimens). Caudal papillae comprising one subdorsal and one subventral pair, conspicuous in specimens from Pretoria, Viljoenskroon and Pietermaritzburg. Intestine four to six cells in circumference. Rectum 19 (15-20) pm long. Male and juvenile Not found. Locality and habitat Present specimens from the Transvaal: Pretoria (exact locality unknown), collected by K.P.N. Kleynhans, September 1981; Cape Province: Barkly East, from soil among the roots of grasses next to the road between Lady Grey and Sterkspruit, 13 Km from Lady Grey, collected by E. van den Berg, December 1977; from soil from a vineyard on the farm "Boesmansdrif", between Bonnievale and Swellendam, collected August 1966 (collector unknown); Orange Free State: Viljoenskroon (habitat unknown), collected by E. van den Berg and A. Madeira, October 1981; Natal: from soil under a yellowwood tree in the Bota nical gardens, Pietermaritzburg, collected by P. van Niekerk, October 1968 and Okavango and Botswana: from soil under a sausage tree standing at the edge of the water on Boba island, collected by J. Heyns and A. Coomans, August 1989. Specimens Botswana specimen on slide RAU 5281 in the nematode collection of the Rand Afrikaans - 262- University, Johannesburg; other specimens on slides 1325, 3683, 7407, 8608, 18135 and 21466 in the National collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. Mylonchulus agriculturae Coetzee, 1966 (1 Synonym of M. brachyuris) (Figure 5; Table 8) Females were collected from Sabie, Stellenbosch, Hhluhluwe and Clocolan. Their morphometries are in agreement with the values given for M. agriculturae as well as for M. brachyuris. Female Cuticle with fine striations, striations indistinct in specimen from Sabie. Lateral field 28 (23-31) % of corresponding body width wide; body pores inconspicuous. Lip region slightly offset; papillae distinct. Amphid aperture slit-like, 4 pm wide and situated at level of dorsal tooth apex in specimens from Sabie, Clocolan and one specimen from Hhluhluwe, just anterior to this level in other specimen from Hhluhluwe and just posterior to this level in specimen from Stellenbosch. Fovea cup-shaped; amphidial canal and fusus with sensilla inconspicuous. Buccal cavity goblet-shaped, walls about 1,5 pm thick, without striations except in specimens from Hhluhluwe where fine striations are visible in posterior region of buccal cavity walls. One pair of geusids opening subventrad into buccal cavity. Dorsal tooth opposed by two submedian teeth, subventral denticles arranged in seven rows. A small denticle is present in dorsal wall just anterior to dorsal tooth in all the specimens. Oesophagus strongly muscular; oesophageal gland outlets distinct in all specimens, gland nuclei only conspicuous in one specimen from Hhluhluwe. Nerve ring 92 (77-102) pm from anterior end. Excretory pore not seen. - 263- Vulva small and transverse in specimens from Stellenbosch and Clocolan, evaginated in specimens from Hhluhluwe. Sclerotized pieces in vagina not seen in specimens from Stellenbosch and Hluhluwe, conspicuous in specimen from Clocolan. No sphincter muscle observed at uterus-oviduct junction. Ovaries well developed. One egg measuring 90 x 46 pm present in anterior uterus of Stellenbosch specimen, one egg each measuring 80 x 48 pm and 85 x 48 pm in anterior and posterior uterus of Clocolan specimen. No sperm cells present. Tail short, conoid and slightly arcuate ventrad. Caudal glands arranged in tandem and ending in a subterminal spinneret in specimen from Clocolan and one specimen from Hhluhluwe, obscure in other specimens. Caudal papillae indistinct. Intestine four cells in circumference. Rectum 19 (15-22) pm long; rectal glands conspicuous in one specimen from Hhluhluwe. Remark One specimen from Sabie is morphologically similar to the other specimens, but has a shorter body and a much shorter tail (see Table 8). Male and juvenile Not found. Locality and habitat Present specimens from Sabie, Transvaal, collected in 1966 (collector and exact locality unknown); from soil under poplar trees on the farm of Mr. van Dyk, between Vlottenberg and Lyndoch Stellenbosch, Cape Province, collected by P.C. Smith, July 1966; from soil under a thorn-bush at the Maphumulo camping site, Hhluhluwe Game Reserve, Natal collected by J. Heyns, May 1986 and on the farm "Rustig", Clocolan, Orange Free State, collected by J. Heyns, July 1969. - 264- Specimens Specimens from Hhluhluwe on slides RAU 3884 and 3889 in the nematode collection of the Rand Afrikaans University, Johannesburg; other specimens on slides 7319, 7797 and 10015 in the National collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. Mylonchulus incurvus (Cobb, 1917) Andrassy, 1958 (Figure 6) A single young female from soil under coffee plants at the Research Institute at Nelspruit, Transvaal, probably belongs to M. incurvus. It differs from Cobb's original description by the shorter body, much shorter tail and smaller buccal cavity. Williams (1958) and Coetzee (1968) from Mauritius and South Africa, respectively, also reported smaller specimens. Measurements Female (n = 1): L = 0,73 mm; a = 24,3; b = 3,0; c = 52,4; c' = 1,0; V = 62% ; buccal cavity = 20 x 10 pm; tail = 14 pm Brief description Lip region 19 pm wide, 4 Pm high. Amphid aperture situated at level of dorsal tooth apex, fovea cup-shaped, walls about 1 pm thick. One pair of geusids present. Dorsal tooth at 15 % of buccal cavity length, opposed by two submedian teeth. Subventral denticles five rows. Nerve ring 77 pm from anterior end. One pair of endolids present in oesophageal lumen just anterior to nerve ring. Excretory pore not seen. Vulva transverse; vagina with sclerotized pieces. No sphincter muscle present at uterus-oviduct junction. Tail arcuate, sharply bent about midway to terminus. Spinneret slightly subterminal. Caudal glands and caudal papillae obscure. Rectum 16pm long. - 265 . Specimen Collected by J. Heyns, 26 April 1966 on slide 7475 in the National collection of Nema todes, Biosystematics Division, Plant Protection Research Institute, Pretoria. MyJonchuJus brevicaudatus (Cobb, 1917) Altherr, 1954 (Figure 7) Two females collected at Paarl, Cape Province correspond well to previous descriptions of M. brevicaudatus. Measurements Females(n = 2): L = 1,05 mm; a = 29,2-35,0; b = 3,6-3,8; c = 42,0-45,7; c' = 0,9 1,0; V = 59-60 %; buccal cavity = 20-21 x 9-11 pm; tail = 23-25 pm Brief description Lip region truncate, 19-24 pm wide, 4-5 pm high. Papillae distinct. Amphid aperture 3,5 4,0 pm wide, situated at level of dorsal tooth apex; fovea cup-shaped. Buccal cavity goblet-shaped, walls about 2 pm thick without striations. Dorsal tooth large (not massive as reported by Mulvey, 1961), at 17-20 % of buccal cavity length, opposed by two small submedian teeth. Subventral denticles five to six rows. Geusids present. Nerve ring 88 pm from anterior end. Excretory pore not seen. One pair of endolids present in oesophageal lumen. Oesophagus weakly muscular. Oesophageal gland outlets distinct, gland nuclei indistinct, except dorsal gland nucleus in one specimen. Posterior region of oesophagus slightly widened in one specimen. Vulva a small transverse slit with scierotized lips. Vagina with sci erotized pieces. One egg each, measuring 98 x 42 pm and 90 x 37 pm, present in anterior uterus of each specimen. Sphincter muscle not seen. Tail short, conoid" arcuate ventrad with a subterminal spinneret. Caudal glands and papillae obscure. Rectum 21 pm long. - 266- Remark One flattened specimen from soil among the roots of flowers on the farm "Rustig" at Clocolan in the Orange Free State, deviates somewhat from the above description. It has a more anteriorly situated dorsal tooth apex at 9 % of buccal cavity length, slightly larger submedian teeth and a smaller c-ratio of 36,4. Locality, habitat and specimens Paarl specimens collected 24 August 1966 (collecter unknown) on slides 7357 and 8076 in the National collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. Specimen from Clocolan collected by J. Heyns in 1970, on slide RAU 327 in the nematode collection of the Rand Afrikaans University, Johannesburg. Mylonchulus striatus (Thorne, 1924) Andrassy, 1958 (Figure 8) A single male from a sanddune at Gansbaai, Cape Province fits the description of Mylon chulus striatus of Mulvey (1961). Spicules are, however, longer (37 pm in Mulvey's specimen). Measurements Male (n = 1): L = 0,96 mm; a = 25,9; b = 3,7; c = 38,4; c' = 0,96; buccal cavity = 20 x 9 pm; tail = 25 pm; spiculum = 50 pm; lateral guiding piece = 9 pm Brief description Lip region well developed, 24 pm wide, 8 pm high. Amphid aperture indistinct. Buccal cavity goblet-shaped, walls 1 pm thick. Dorsal tooth large, submedian teeth small. Subventral denticles eight rows. Geusids present. Nerve ring 86 pm from anterior end. Excretory pore not seen. Outlets of oesophageal gland nuclei conspicuous. Testes paired, - 267 - opposed. Spicules slender, distal terminus rounded, proximal terminus bifurcate. Lateral guiding pieces bifurcate. Gubernaculum crescent-shaped. Supplements papilliform, consisting of one adanal pair and ten ventromedian ones. Tail conoid, slightly arcuate ventrad. Caudal glands obscure; spinneret rudimentary. Caudal papillae inconspicuous. Specimen Collected by J. Heyns, 15 October 1988 on slide RAU 5429 in the nematode collection of the Rand Afrikaans University, Johannesburg. Mylonchulus Species A (Figure 9) A single female from soil among the roots of coffee plants at the Research Institute at Nelspruit, Transvaal is close to Mylonchulus siqmeturus (Cobb, 1917) Altherr, 1953. It differs from the latter species by a shorter body, shorter tail and the slightly subterminal position of the spinneret. Measurements Female (n = 1): L = 0,95 mm; a = 26,4; b = 3,3; c = 63,3; c' = 0,75; V = 64 %; buccal cavity = 20 x 15 pm; tail = 15 pm Brief description Lip region truncate, slightly offset, 27 pm wide, 6 pm high. Amphid aperture at level of beginning of buccal cavity. Buccal cavity goblet-shaped, walls about 2 pm thick, posteriorly finely striated. Geusids inconspicuous. Dorsal tooth apex at 15 %. Subventral denticles six rows. Nerve ring and oesophageal gland nuclei indistinct. Excretory pore not seen..Reproductive branches obscure. Vulva transverse; vagina with scierotized pieces. Tail short, constricted about midway, then cylindroid with rounded terminus. Spinneret - 268- subterminal. Caudal glands obscure. Rectum 12 pm long. Specimen Collected by J. Heyns 20 April, on slide 7474 in the National collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. Mylonchulus Species B (Figure 9) A single female specimen from soil among the roots of sugarcane at Mtubatuba, Natal is close to Mylonchulus subterraneus (Schneider, 1940) Andrassy, 1958. Schneider erected this species on the basis of a single female with illustrations of only the tail and reproductive system, which is monodelphic and prodelphic. The spinneret appears to be subterminal. Measurements Female (n = 1): L = 1,11 mm; a = 30,8; b = 3,7; c = 25,2; c' = 1,8; V = 55 %; buccal cavity = 22 x 11 pm; tail = 44 pm Brief description Lip region truncate, 23 pm wide, 9 pm high. Papillae distinct. Amphid aperture 3 pm wide, situated at level of dorsal tooth apex. Fovea cup-shaped. Dorsal tooth large, at 23 % of buccal cavity length, opposed by two submedian teeth. Subventral denticles five rows. Geusids present. Nerve ring 80 pm from anterior end. Excretory pore not seen. Vulva transverse; vagina with sclerotized pieces. Reproductive system mono-prodelphic; post uterine sac present. Tail conoid, arcuate ventrad and sharply bent. Caudal glands in tandem; spinneret subterminal. Caudal papillae indistinct. Rectum 20 pm long. - 269- Specimen Collected by J. Heyns and M. Luc, November 1984, on slide RAU 1555 in the nematode collection of the Rand Afrikaans University, Johannesburg. Mylonchulus Species C (Figure 9) A single male specimen, collected from soil under barley and rye at Ceres, Cape Province, is somewhat flattened, but comes close to Mylonchulus cereris Coetzee, 1966, particularly regarding the tail shape. It differs from this species by the absence of caudal glands and lateral guiding pieces and by a more anteriorly situated dorsal tooth apex. Measurements Male (n = 1): L = 1,21 mm; a = 24,2; a'= 29,5; b = 3,7; c = 39,0; c' = 1,3; buccal cavity = 22 x 14 pm; tail = 33 pttv; spiculum = 55 pm Brief description Lip region well developed, 27 pm wide, 7 pm high. Papillae distinct. Amphid aperture inconspicuous. Buccal cavity goblet-shaped, walls posteriorly finely striated. Dorsal tooth apex at 9 % of buccal cavity length, opposed by rather well developed submedian teeth. Subventral denticles seven rows. Geusids present. Nerve ring inconspicuous. No excre tory pore seen. Outlets of oesophageal gland nuclei seen; gland nuclei indistinct. Testes paired, opposed. Spicules slender, distal terminus rounded, proximal terminus bifurcate. No lateral guiding pieces seen, gubernaculum crescent-shaped. Supplements papilliform, consisting of one obscure adanal pair and eleven ventromedian ones. Tail short, conoid, caudal glands and spinneret absent. Caudal papillae inconspicuous. - 270- Specimen Collected by C. Krezman, October 1963, on slide RAU 98 in the nematode collection of the Rand Afrikaans University, Johannesburg. Granonchulus subdecurrens Coetzee, 1966 (Figure 10; Table 10) Coetzee (1966b) was the first to describe this species found at Elandshoek and at the Kruger National Park. Mulvey & Jensen (1967) recorded females from Nigeria with a slightly more posterior vulva position and with longer tails. Seven female specimens from Namibia were identified as this species. These are in agreement with the type population, except for slightly longer bodies and longer tails. Female Cuticle with faint transverse striations. Lateral field 25 (21-28) % of corresponding body width wide. Body pores inconspicuous. Lip region truncate, slightly offset. Amphid aperture ovoid, 4 pm wide, situated at level of dorsal tooth apex in four specimens, just anterior to this level in two specimens, almost at beginning of buccal cavity in one specimen. Fovea cup-shaped; amphidial canal and fusus with sensilla indistinct. Buccal cavity ovoid, walls about 1 pm thick, no striations seen. Dorsal tooth moderately developed. Subventral denticles arranged as described by Coetzee (1966b). Nerve ring 94 (89-104) pm from anterior end. Excretory pore not seen. Oesophageal gland outlets distinct in all specimens; gland nuclei evident in only one specimen. Reproductive branches very short. Vulva a small transverse slit with unsclerotized lips. Vagina with large sci erotized pieces. No sphincter muscle observed at uterus-oviduct junction as reported by Coetzee (1966b). (Examination of the type population revealed no - 271 - sphincter muscle). Ovaries short with only a few oocvtes, Tail conoid, arcuate ventrad with a rounded terminus, with three small tandem caudal glands present, their ducts ending in a terminal spinneret. Only one subventral pair of caudal papillae distinct. Intestine four cells in circumference. Rectum 25 (21-28) pm long. Male and juvenile Not found. Locality and habitat Present specimens from soil among the roots of grasses next to the road, 30 Km south of Otjiwarongo, Namibia, collected by A. Coomans and J. Heyns, July 1986. Specimens On slides RAU 2560, 2567, 2568 and 2587 in the nematode collection of the Rand Afrikaans University, Johannesburg. KEY TO THE MYLONCHULUS (COBB, 1916) ALTHERR, 1953 AND GRANONCHULUS ANDRaSSY, 1958 SPECIES OF SOUTHERN AFRICA 1. Subventral denticles arranged in transverse rows...... •...... 2 Subventral denticles scattered irregularly 9 2. Spinneret terminal. 3 Spinneret subterminal. 7 3. Spinneret rudimentary Mylonchulus striatus .Spinneret not rudimentary 4 - 272 - 4. Tail longer (65-100 pm); slightly arcuate ventrad, cylindroid in anterior two-thirds Mylonchulus lacustris Tail shorter (22-61 pm); not cylindroid in anterior two-thirds 5 5. Tail conoid, then abruptly cylindroid resulting in a short digitate part set off from the rest of the tail.. Mylonchulus sigmaturus Tail without short digitate part 6 6. Tail more slender; slightly to more strongly arcuate ventrad Mylonchulus minor Tail stout; very slightly arcuate ventrad Mylonchulus cereris 7. Tail sharply bent near middle; spinneret only slightly subterminal Mylonchulus incurvus Tail not sharply bent near middle; spinneret subterminal. 8 8. Tail longer (30-46 pm); more slender Mylonchulus agriculturae Tail shorter (23-25 pm ); more stout Mylonchulus brevicaudatus 9. Caudal glands absent; tail terminus more acute Granonchulus decurrens Caudal glands present; tail terminus more rounded Granonchulus subdecurrens ACKNOWLEDGEMENTS Thanks are due to Dr. Esther van den Berg for the loan of specimens from the National collection of Nematodes, Biosystematics Division, Plant Protection Research Institute, Pretoria. Financial support from the Foundation for Research and Development of the CSIR is gratefully acknowledged. - 273- REFERENCES BUANGSUWON, D.K. & JENSEN, H.J. 1966. A taxonomic study of Mononchidae (Enoplida:Nemata) inhabiting cultivated areas of Thailand. Nematologica 12: 259 274. BAQRI, S.M. & JAIRAJPURI, M.S. 1973. Studies on Mononchida V. The Mononchs of EI Salvador with descriptions of two new genera, Actus and Paracrassibucca. Nematologica 19: 326-333. BuTSCHLI, O. 1873. Beitrage zur Kenntnis der Freilebenden Nematoden. Nova Acta Leopoldina. Abhandlungen der deutschen Akademi der Naturforscher Leopoldina 36: 1-444. CASSIDY, G.H. 1931. Some Mononchs of Hawaii. Hawaiian Planters Record 35: 305 339. CHAVES, ELiSEO. 1990. Mononchida (Nematoda) from Argentina. Nematologica 36: 181-193. CLARK, W.C. 1963. Notes on the Mononchidae (Nematoda) of the New Zealand region with descriptions of new species. New Zealand Journal of Science 6: 612-632. COBB, M.V. 1915. Some freshwater nematodes of the Douglas Lake Region of Michigan, U.S.A. 1i'ansactions of the American Microscopical Society 34: 21-47. COBB, N.A. 1893. Nematodes mostly Australian and Fijian. Macleay Memorial Volume. Linnean Society of New South Wales: 252-308. - 274· COBB, N.A. 1917. The Mononchs (Mononchus Bastian, 1866). A genus of free-living predatory nematodes. Soil Scientist 3: 431-486. COETZEE, VICTORIA 1966a. Species of the genus Mylonchulus (Nematoda: Mononchidae) occuring in southern Africa. Nematologica 12: 557-567. COETZEE, VICTORIA 1966b. Species of the genera Granonchulus and Cobbonchus (Mononchidae), occuring in southern Africa. Nematologica 12: 302-312. COETZEE, VICTORIA 1968. Mononchidae (Nematoda) of southern Africa. South African Journal for Agricultural Sciences 11: 403-414. DE MAN, J.G. 1876. Onderzoekingen over vrij in der aarde levende Nematoden. Tijdschrift der Nederlandsche Diekundige Vereeniging 2: 78-196. GOODEY, T. 1942. Observations on Mononchus tridentatus, M. brachyuris and other species of the genus Mononchus. Journal of Helminthology 20: 9-24. JAIRAJPURI, M.S. 1970. Studies on Mononchida of India III. The genus Mylonchulus (Family Mylonchulidae Jairajpuri,1969). Nematologica 16: 434-456. JAIRAJPURI, M.S. & KHAN, W.U. 1982. Predatory Nematodes fMononchidaJ with special reference to India. Associated Publishing Company. New Dehli, India.129 pp. JENSEN, H.J. & MULVEY, R.H. 1968. Predaceous Nematodes (Mononchidae) of Oregon. Oregon State University Press: 1-57. - 275 - KHAN, W.U. & JAIRAJPURI, M.S. 1979. Studies on Mononchida of India XII. The genus Mylonchulus (Cobb, 1916) Altherr, 1953 with descriptions of three new species. Nematologica 25: 406-418. LOOF, P.A.A. 1964. Free-living and plant parasitic nematodes from Venezuela. Nematologica 10: 201-300. LORDELLO, L.G.E. 1970. Research on nematodes of the family Mononchidae encountered in Brazil. Anais de Escola Superior de Agricultural "Luiz de Queiroz" 17: 15-48. MOHANDAS, C. 1972. Notes on Mononchida (Nematoda) from soils of Kerala. Current Science 22: 818-819. MULVEY, R.H. 1961. The Mononchidae: A family of predaceous nematodes I. Genus Mylonchulus (Enoplida: Mononchidae). Canadian Journal of Zoology 39: 665-696. MULVEY, R.H. & JENSEN, H.J. 1967. The Mononchidae of Nigeria. Canadian Journal of Zoology 45: 667-727. PATIL K.J. & KHAN, W.U. 1982. Taxonomic studies on nematodes of Vidarbha region of Maharashtra, India: III. One new and two known species of Mylonchulus (Nematoda: Mononchoidea). Indian Journal of Nematology 12: 158-160. POPOVICI, JULIANA. 1990. Studies on Mononchida (Nemata) from Romania. Nematologica 36: 161-180. SCHNEIDER, W. 1940. Neue Freilebende Nematoden aus Hohlen und Brunnen 1. Nema toden aus Jugoslawischen Hohlen. Zoologischer Anzeiger Leipzig 132: 84-94. - 276- THORNE, G. 1924. Utah nemas of the genus Mononchus. American Microscopical Socie ty 43: 157-171. WILLIAMS, J.R. 1958. Studies on the nematode soil fauna of sugar cane fields in Mauritius I. The genus Mononchus (Trilobidae, Enoplida). Mauritius Sugar Industry Research Institute, Occasional Paper 1: 1-13. WINISZEWSKA, G. 1985. Six species of Mononchoidea (Nematoda) new to the fauna of Poland. Fragmenta Faunistica 3: 29-38. (Published in Phytophylactica 24) - 277 - 'mIlLE 1: lbttililrl llc data of lICJII!! pop.latlmc of Mttarb.1 118 lacustt1a (Qlbb. N.A. in Qlbb. HoV•• 1915) AofI3ssy. 1958 M. lacusttis Cobb.N.A. Cobb.N.A. Cobb's UllpUblished notes. aceord1ng to Present Spec:zcs in CobboM.V. (1917) ~vey & JensEn (1967) (191.5) Michigan M1c:h1gan. M1cil1gan nor:l.da Pa1laIIB N1ger'..a Setlagole. Volklrust. EdenVille. ladybraDd. Faures:tI1til PacmIB. cape Natal O.F.S. O.F.S. O.F.S. nortda n 1 ~ I" 1 .f 2.f+ 3W 1 ~*) 5.f.':. 1 of. 1 -to 1 .f 1 -to 1.f- Um) 1.7 1.10 - 1.8-1.9 1.1-1.3 1.5 1.7(1.5-1.9) 1.71 1.84 1.66 1.65 1.10 N a 62.9 23.8 30(25-38) 26.3 33,5 38,6 28.9 20.8 "'-J - - - - co b 3,7 3.2 - - -- 3.8(3.6-4.0) 3.4 3,3 3.4 3.7 2.7 c 20 2S - 16.7 25-33 20.0 19(17.4-20,0) 18.2 18.6 19.5 18.3 16.9 c' - 1.9 -- - - [2.4] 2.2 2.8 2.9 2.6 2.0 V% 64 63 - - - - 65(63-57) 64 63 65 64 62 Lip reg100 Width - [24J [26.3Jx - -- [26.8] 38 34 30 31 34 height - [5) [6]x - -- [8] 10 13 9 9 10 azccu cavity lEngth - [29.3J [33]x - - 32 30-32+ 41 38 36 38 34 Width - [14.71 [15.8Ix - - 20 20 24 24 17 18 16 Ibrsa.l tooth apex % - [13.6J [13,5Jx - - - [16] 17 21 21 18 18 Tail length 85 44 [69.0]x 1OB-115 39-44 75 90(00-100) 94 99 85 90 65 Spi01l.LlD length ------SUpplel1l!Dts ------ [J • CalOl1.ated fran ot1g:l.na1. Ulustr.1ticns [ Jx • CalOl1.ated fran ~vey & JEIlSE!Q's (1967) redr:M1 illustr:lticns of Cobb's IrlpIlbl.1shed wr!c [ J* • Probably ~ite f:!.gures far alllocallties * Probably !+Ilarln1.us trd.nor acam11ng to ~vey & Jensen (1967) (*) • !+Iloochulus lacustr1:J acccrd1ng to present aut";ar + • No M. IlXXltmJS (• Ii. l.acustrts) MJlvey Coet::ee C"..t1~ts of (1961) (1996a) Coet::ee's speciJIEna Ottalo:a. Dw:ars R1vet'. Paarl. lbeispruit. !be::.>llruit. Canada Cape Cape Tr:msvaal 'lxal:s ....aal n 10 -r-e- 3d~ 1 ~ 1 ~ 5* 5 ..... L(l!IlI) 1.82(1.60-1.90) 1.65(1 •.55-1.30) 1.9 2.0 2.0( 1.8-2.2) 2.1 (2.04-2.22) a JJ.l(26-37.2) 30.2(27.3-33.0) 38 34 27.8(27-29) 31.2()).1-32.4) b 3.5(3.2-3.6) 3.2(3.1-3.3) 3.4 3.4 4.3(3.H.7) 3.70•.5-3.3) e ZO.1(l6.5-24,O) ZO.0(18.2-21.1) 32 33 20.2(18-22) 22.9(::!.3-23.4) c' [2.2] [2.1] [2.4J* -- 2.1(2.0-2.3) N v:; 62.5(59-56) 62.2(59-64) 63.2(52-54) 'oJ - 66 66 CO Up ~cn ~dt.'l [33.3J - [34.3]* - - 34.4{:3-J6) be4ht [5J - [10.6J* -- 11.2(11-12) ~C3V1=71~ 33-35+ 33-39+ [37.9J* -- 37,9(:7-39) ll1dt.'l :0-2.::+ :0-21+ [18.1 J* - - 18...(17-19) !m":la.l tooc ape:t : [18.1 J - [26J* - - ZO.4{:8-24) 'I'a1l ~~ 92(75-105) 82(80-85) [lOOJ* - - 92.0(~5) SpiCl1t.::l lecgC - 64(60-<58) - - -- SUpplE1:El::t.3 - 13-14 - - - - [] Co11~ted fran ~ illust=:lt::!.cns [ ]x • Co11e::.tl.1ted fran MJ.lvey & :ecsen's (1967) ~ i1lust::':1t:!.cns of C::l:b's 1l:lpUbU.shed'MOrk [ ]* • P::oCably ~te figures far all 1oc:ll1!::!.es * P::obably ~1cn:.":J.I.l:S :ti= a=r'~ to H.1l\"e'J & :ecsen (1967) (*) H71cn:...... uus L1=t:::.s a=r'~ to preselt aut.':or + No~g1";l!ll , TABI.B 2: Morolnnetrlc data of sam populati Cobb Cobb Williams }tllvey Loof Beangsuson & Jensen (1893) (1917) (1958) (1961) (1964) (1966) Fiji - Mauritius Florida & Mi:3souri* Venezuela* Thail.an:i* n 1 .;. -. 1 .;. 1 .;. 5H 8++x 1 -+ L(mn) 1,0 1,1 1,1 1,09(1,00-1,20) 0,9-1,35 0,96 a 23.2 37,9 31,4 27,3(22,2-33,3) 25-30 26 b 3,3 3,8 3,6 3,9(3,6-4,3) 3,3-3,7 3,8 c 20,0 30.3 22,2 23,2(19,2-26,2) 23-32 24 N CO c' 1,9 1,7 1,4 [1,9] - [1,6J o V7. 60 60 60,3 55(52-58) 58-60 61 Up width - [26.7J [24,1] [22.5] - [27,71 height - [7,0] [8.0] [6,71 - [9,3] Buccal cavity length - [22,6] [24,1J 2D-23x 23-27 25 width - [17,3] [15,2] 12-14x 11-13 13 Dorsal tooth ape.'< % [15] [23,5] [22,2] [29J - [29,lJ Tail length 50 36,3 49,5 47(42-52) - [50J [J • Calculated fran the original illustrations [ ]0 .. Calculated fran auvey & Jensen':3 (1967) redrasn illustrations of Cobb t s tmpublished ~rk .-. • Was !!:..lacustris (synonymized by }tllvey & Jensen, 1967) x • No average g1ven (+) • Range incllX!e:> all populations + • K:J:3t probably the :>alOO populations TABLE 2: }brlXnretrlc. data of SOle ~"aHms of MylCDChl1.us m:imr (QXi). 1873) AIxir3ssy. 1958 (continued) l-W.vey & Jensen Jairajpuri Khan & Jaraijpuri O1aves (1967) (1970) (1982) (1990) Nigeria Java Panana India (+) India + Argel.tina n 10 ++ 3++ 1 ~ 26 :f+ x ?++x 3:;:+ L(mn) 1,2(1,1-1,4) 1,02-1,16 X - 0,82-1,40 0,82-1,32 1,16(1,13-1,17) a 25(21-29) - - 18-32 18-32 31,9(30-34,2) b 3,7(3,4-3,9) - - 3,0-3,8 3,0-3,8 3,3(3,3-3,4) c 31(30,0-34,3) 25,0 - 24-47 32-47 21,7(:0,5-23,2) !'.) co c' [1,5] - [1,4]° [1,8] - 1,8(1,8-1,9) ... V% 57(55-60) - - 54-67 54-67 58,3(56-50) Up width [27,7] - [24,0]° [23] 20-25 24,3(24-25) height [9,2] - - [7,3] 7-10 [8,3] Buccal cavity Length 25-29:< - 30[32,2]° 21-25 21-25 24,3(2..."-25) width 15-lax - 24[17,8]° 12-15 12-15 16 Dorsal tooth apex :: [17,2] - [17]0 [20] 24-30 26(2...."-27) Tail length 39(35-43) 44 [50]0 35-50 35-50 53,3(50-57) [] .. Calc:J.1ated fran the orig:ina.l illustrations [ ]0 .. Calc:J.1ated from M.l.l.vey & Jensen's (1967) redraen illustrations of Cobb's unpublished wotk * .. Was M. lacustris (synooymized by !otllve'l & Jensen. 1967) x .. No average g:lven (+) .. Range include:; all pcpulations + as M:lst probably the :>a:Ie populations TAIllB 3: Ibl'llha:tz1c: data of __ pop"1aHrno of MylarlJl1ns 1mIl:I.iena1s (<:aaaidy. 1931) Ao:b:3asy. 1958 Cassidy coeuee H.1lvey & Jensen Jairajpuri llaqr1 & ! n 14- 16 .;.;:.' J 18 .;.;:. 5';';:' x 2';';:' 200 .;.;:. 28 'H- x .;:r. x 10 :;.,. L (lDlI) 1,00 0,8-1,5 1,1(0,9-1,3) 0,87-0,98 0,6-0,84 1,09(0,70-1,35) 0,78-1,30 0,7-1,35 1.12(0,96-1,37) a 33,3 19-30 26(22-32) 2.."-26 19-20 25(17-30) 21-30 17-30 27,7(23,7-32) b 3.6 3.1-4,1 3,5(3,1-4,0) 3,2-3,6 3.0-3,1 3,2(2.9-4,0) 2,6-3.8 2,9-4,0 3,6(3.2-3,9) c 25 21-35 33(26,3-43,5) 27-31 25-27 38(25-54) 22-30 2.."-54 27(20-33.4) '"(X) c' 1,3 [ 1,8] [1,5] . [1,8-1,9] - - 1,5-2,0 [1,9] 1,5(1,5-1,8) v: 61 5~ 57(.54-02) ~O 60-63 62(50-70) 54--61 51-58 57,2(5~) '" Up width [27,1] 28,8 [22,5] 20-25 -- 20-25 16-:9 23,4(23-25) height [9] - [5,2) 7-10 - - 5-7,5 5-9 [8,3] IluccaJ. <:::IV1ty length. [27,1) [:ll,3) 20-23 x 22-25 20-23 17-30 x 21-26 17-30 23.5<22-27) width [13,6] [17,4] 11-13 x 14-17 12-15 10-16 x 11-17 10-16 15.5(15-17) torsal tooth apex % [21] [18! [27] [21] - 15-35 x 25-43 15-30 25(23-27) Tail 1etlgth 40 [45,5! 32(23-42) 30-40 23-35 24-45 x 37-43 24-45 41,5(34-49) [ ] • Calculated fraD the orlgina1 UlU:ltraticns * • 'iGs M. 1B=t::'is (a=t'd1ng to Coetzee, 1968) (*) • Range 1nclu.1e:J all papulatioas x • No avet'3ge g1.'Je1 TABLE 4: !tmlbcmet:rlc data of present pcpnlat1cns of Mylmdulus IIIimr (Collb, 1873) AmoIssy, 1958 Tr:m:lvaa1 Gape Province Orange Free State Natal Namibia Boc,,-wana ? Devon austen- Kamt1- Augrab1es Paarl Re:lders- Faure- Vlljoens- Eden- lUuh1uwe Verulam Unshlan- Otjiwa- Cl ~ n 1 :;. 1 :r- 1 :r- 1 :r- 4+;:' 1 OJ!. 1 + 1 of. 1 :;. 1 ~ 2H 1 + 1 of. 1 3';'; L (am) 1,41 1,64 1.12 0.87 1.4 (1.31-1.45) 1,06 1,65 1.07 1.83 1.41 1.31-1.36 1.29 1.37 1.12 1.06 (0.9-1.16) a 24.7 34.1 33.9 21.8 36.5(35.4-39.2) 30.3 33.7 32,4 41.6 28.2 31.6-32.8 33.9 32.6 29.3 30.4 (29.0-31.7) b 3,5 4,0 3.5 3.6 4.2 (4.0-+.3) 3.9 4.1 3,7 4,1 4.0 3,7-3.9 3.7 3,2 3.7 3,8 (3.6-3.9) 35,8 34,6 (33.1-37.5) I',) c 40.3 40.0 38.6 25.6 28.1(25.7-30.2) 31.6 27.0 42.8 42.6 33.6 28.9-29.8 35.1 36.1 OJ c' 1.3 1.4 1.4 1.5 2.0 (1,9-2.1) 1,2 2.1 1.5 1.5 1.4 1.7-1,8 1.4 1.4 1.6 1.6 (1.4-1.8) W ~ 63 62 57 53 56.5(53-03) 56 69 56 60 61 63-64 64 66 54 54.7 (53-57) Lip Width J2 29 22 23 24.3(21-29) 26 30 23 32 27 28-30 29 28 22 21.3 (20-23) height 6 5 6 6 6.1 (5-7) 6 6 6 7 6 5-7 6 6 7 6 a=J. C:lV1ty length 31 J2 25 23 25.5(24-30) 22 29 24 35 29 28-30 31 29 23 22.7 (22-24) Width 17 16 12 12 11.300-14) 15 14 1l 15 LJ 12-14 15 13 10 10 Dorsal tooth apex :: 21 19 24 24 2O.0(17-22) 23 24 21 23 21 20-21 23 18 22 23.7 (23-25) Tail length 35 41 29 34 49.8(48-51) 33.5 61 25 43 42 44-47 36 39 31 30,7 (24-35) TABLE 5: New distribution records and data on specimens of Hylonchulus minor (Cobb. 1873) Andrassy. 1958 Locality Slide number Collection Collector Date Transkei Port St. Johns 8991 PPRI J. Heyns 7 Jan. 1965 Transvaal Devon 10144 PPRI I. Botha & D. Argo 1 Feb. 1972 Rustenburg 21131 PPRI E. van den Berg 12 March 1980 Komatipoort 22523 PPRI E. van den Berg 5 Feb. 1985 Cape Augrabies 813 RAU J. Heyns ? July 1983 814 RAU J. Heyns ? July 1983 N 3543 RAU J. Heyns 18 July 1983 ce ~ 8902 PPRI J. Heyns ? Oct. 1968 Paarl 7357 PPRI ? ? Aug. 1966 O.F.S. Reddersburg 15699 PPRI J. Louw & 13 March 1979 J. du Plessis Fauresmith 20103 PPRI E. van den Berg 6 Feb. 1980 Viljoenskroon 21451 PPRI E. van den Berg 23 Oct. 1981 Edenville 20175 PPRI E. van den Berg 3 March 1981 Natal Hluhlu'o1e 3881 RAU J. Heyns 29 May 1986 3894 RAU J. Heyns 29 May 1986 Veru1am 10489 PPRI ? 16 July 1969 Umhlanga 1532 RAU J. Heyns & M. Luc ? Nov. 1984 Namibia Otjiwarongo 1263 RAU J. Heyns 23 July 1983 Botswana Okavango 5223 RAU J. Heyns & A. Coomans 31 July 1989 5225 RAU J. Heyns & A. Coomans 31 July 1989 5226 RAU J. Heyns & A. Coomans 31 July 1989 TABLE 6: Habitat and localities of the specimens used for the description of Hylonchulus ~ (Cobb. 1873) Andrassy. 1958 o r t St. Johns: from soil under grasses on second beach. between Lloyds' Cottage and the sea evan: from soil under mealies next to road. about 20 km from Devon ustenburg: from soil under natural vegetation next to road between Koster and Rustenburg ~omatipoort: from soil under Acanthaceae. 8.7 km from Komatipoort IAugrabies: from wet sand in the caravan park Paar1: from soil under citrus trees on the fa~ of Mr M.L. Durr. Hartebeeskraal ~eddersburg: from soil under grasses next to road bet~een Bloemfontein and Wepener. 12 km from Reddersburg turnoff Faure:lmith: from soil under natural vegetation on the farm of Mr D van Rensburg Viljoen:lkroon: from soil under an Acacia tree next to the gravel road to Viljoen:lkroon co Edenville: from soil under natural vegetation on the farm "China" of Mr AM Strydom. 10km from Edenville U'l'" ~uhluwe: from soil under a thorn-bush at the Maphumulo camping site Verulam: from soil under sugarcane ,Otjiwarongo: from soil under grasses. 30 km south of Otjiwarongo Okavango: from soil under herbs and palm trees on Boba Island (near Jedibe) in the Okavango Swamps TAIIlB 7: MJniLuetr1c data of lIl1Ithem Afric:an popnlat1ms of Hylmrbnlns s1s!;!Bturus (Olilb. 1917) Altherr. 1953 Accotdi.ng to Coetzee (l966a) Present ~-pec:lJreDS '1'r:lrl:MIal Gape Province Natal Tr:mskei 'I'ran:,-vaal Cape Province O.F.S. Natal Bo~"Io1 MidA:1el.lur6 AliwaJ. Cape Fr:Insch- Mlkatini Pieter- Port St. Pretoria Barclay Lady Bcmievale VU;oecs- Pieter- . Cka~ North Flats hoek Flats mr1t...- Johns East Grey k:rocn mrit...-- bJq oorg n 4 ..... 1 {- I ... 1 ... 2 ..... 1 ... 1 ... 1 ... 1 + 1 ... 1 + 1 ... 1 .;- 1 :;: N L(1lIII) 1,1(1,1-1,2) 1,2 1,0 1,2 1,1-1.5 1.5 1.2 1,25 1,14 1,34 1,39 1,39 1,13 1.:0 OJ a 7(29-33) 28 25 JJ 27-29 29 30 34,7 30,8 29.1 26,2 37.5 36.4 35.1 0) fl' ------42.1 - - - b 3.2(3.1-3.3) 3.3 3.2 3,4 -2.9-3.5 3.5 3.1 3.3 3.1 3.7 3.8 3.5 3,5 3.3 c 26.9(2.5-29) 37 21 37 27-34 29· 27 37.9 51.8 40,6 49.6 39.7 47.0 52,0 F' [1,4] - - [1.3] [1.5] - 1.5 1.1 1,6 1.0 1.3 1.2 1,0 ~ 66(66-67) 65 65 -66 ~3,7 63 66 65 65 63 64 63 64 65 ~p width [19,1] - - - [24.2] [22,1] - 23 23 26 26 24 24 23 height [5.9] - - - [4.5] [7.4] - 6 6 7 5 6 6 8 ~ C3vity1ength [22,1] - - - [24.2] [23.5] - 26 23 25 23.5 24 23 26 width [9,6] - - - (12) [10,3] - 13 12 13 17 13 11 12 IDorsal tooth apex :: [20] - - - [19] [15] - 15 22 16 19 17 17 15 ~aU length [26.5] - - - [JO.3] [39.7] - JJ 22 33 28 35 24 25 .r ]• Cala1lated fran the or1ginal illwtr:lticns 1 • Incorrect average g1...en nBLI!: 8: tt1~data of 8lJIIl pnpllatiaw of twlax:::!J.llus broc:muris (Mtsc:hU., 1S7J) Altherr, 1953 sal twl !:!:.. brac.":v\..-:l.s De !'tin Thorne Wil.l.1ams liIl.vey liIl.vey & Jensen Jensen & liIl.vey Jai..'"3.jpuri & ! Nec.ierl.arx1s U.S.A. Itlur1tius Canada N1gerta Qregal IJxUa A.~t:r.a 10 _ ? ~ ... •'1. , .. n 1 0 1 i- 1 i- 10 ++ 500 200 5++ .- ? 00 . .. ~ L(CIll) 1.69 1,41 1.0 l,z:l(1.13-1.:l8) 1.220,03-1,40) 0.9(0.8-1,0) 0.8-0.9 1.1(1.0-1.2) 0.3-1.32 0.72-1.21 1.06(0.99-1,21) a 39.3 42.7 29.4 25.5(20.0-30.2) 29.6(27.0-32.5) 26(2.3-30) 31-33 30(27-32) 24-15 22-31 24(2."'-15) b 3.4 3.7 3.2 3.50.1-3.6) 3.5(3.3-3,7) 3.2(3.1-3.4) 3.0-3.2 3.6(:3,4-3.8) ~ 2.9-3,0 3.80.3-3.9) e 33,2 39.9 25.0 28.8(25.1-34,5) 32.1(27.1-36.3) 30(18,4-31.7) ~32 37(30-46) 3G-31 33-44 27(25,3-31,2) c' [1,4] - [1.6] - [1,4] [1.3] [1.2J [0.71 n.n [1.2J 1.4(1.:'-1.5) v: - 62 62.1 61(57-64) 57(56-59) - 61(59-64) 5C}-;8 - 59,3(=s-52) Lip regia) Ilidt.'1 [22.7] [zs] - [21,41 [22.2] 2C-.24 21,;co-.:3) OJ - - - - - '-01'" hei,,-ht - - [7.2] [6.7] - [6.4J - [4.4J 7~ - [6.9J kc.:1l C3v1t:y lecgth - [22,71 21-23% 20-23% la-ZOX 18 24(22-26) 21-29 20,Z(18-:1) Ilidth - [11.8J 12-16% 12-17x 9-1oX 10 14(12-16) 12-15 - . 14.5(::'-,5) - - - ZO xr .... "\." Dorsal toot."1 .xpex :: - - [20J [20] - [22J - [23J 24-23 - .-.;\ :.,;:;-:.-, Tail lengt."l [55J J5,3 40 43(:.0-.:.6) J600-:l8) ::9(:6-32) [23.5J [J5J 2.2-30 - 39,2{:;?-:'o) Spiculum leogt."l [61] -- - 47.6(40-55) - 30 - - 35-39 - Llteral guiding pteees B1f'=te - - - Abselt - Absent - - Absent - GJberroc.llum Absm:/oot - - Bifurcate BL.~ta - Through- - illustrated? - - - shape::! Supplmlents 11 - - 12 - 8 - 12 - C1I.x11J. gl..1n;i:I Not 1'.1n:ie:I -l'amem: 'I:3OOeaI Cbso..ore !'aDr:i8:I Cbsc.lre -Tan:lem '!aOOem* Grouped Gro~ illustrated Creuper:K*) [J • ca.J.c:ulated frcm t."le ot".g1nal 1llus:ra:.tcns x • No aver:Jge giveil * • According to the illustr:lUCXl (*) • Accord.1.'1g to the de:>dptiCXl TAIILE 8: )btll.,*, de daOl of __ papJlaHl'DI of Mo!1.aIdu1us l:Jm<:h,ur!.s (1lQl:ac:bl1. 1873) Altherr. 1953 lD1 My1a>l:bJlus agrla.J1tllra1! Qlet:zee. 1966 (continued) M. agriculturae Pre:;ent ~-pecimens Coetzee (l966a) T=Y.la.1 Sabie Stell~ch lUuhluwe Clocolan Tran:.-vaal. Cape Natal O.F.S. n Holotype .j: Allotype a 10 .;.:r. paratype.:l 1 .j: 1 .j: 2H 1 ~ Ua:m) 1.0 1.1 1.0(0.9-1.1) 0,76 1.15 1.02-1,18 1.24 a 26 J2 2.3.3(24-31) 25.3 26,7 30.3-30.9 27.6 b 3.5 3.5 3.50.3-3.7) 3.4 3.7 3.4-3.6 3.9 c 23 27 23.6(22-28) 47.5 :Ja.) 25.7-29.1 34.4 c' f') - [1.5) [l.8) 1.2 1,2 0.5-0.6 1.5 (Xl V% sa - 57.4(55-60) 57 60 53-56 59 CO Up reg1C11 Width - - [22.7] 20 24 21-25 23 heJ.&ht - - [6.8) 5 5 6 8 lUxa.l cavity length - - [22.7] 19 23 22-25 23 Width - - [9.8J 10 15 10-11 10 D:lt':la1 tooth apex :: - - 20-23" 21 17 23-24 22 'till length - [:36.4J [38J 16 30 35-46 36 SpiCJ.1L1l1 length - 48 - -- -- t.terul gu1d1ng pieces - lli.'urc:1te - -- - - OJbetnacuJ.LIlI - With obia.lre - - - 1:Itenl process - Supplement.s - 11 - - - - - C3Wa.l gl.1D1s TaBlem T.ll'de:n TaOOan Ob.lcure Qh;cure 'l'an:lem 'l'aOOem ()• CoUc.J.Ut Thorne Mulvey Winiszewska (1924) (1961) (1985) n 1 :t- 1 0' 1 ; 1 0 1 :t- L(mm) 1.5 1.58 1.5 1.58 1.33 a 46.9 52.7 29.4 33.3 30 b 3.8 3,8 3.8 3.8 3.7 c 25.0 25.0 25.0 25.0 24 N ce c' [1, 9] [1,7] - - 2.0 (0 V1. . 62 - 62 - 61 Lip width [24] - - - - height [6.7] - - - - Buccal cavity length [20.7] - 24 - 22 width [10.71 - 14 - 14 Dorsal tooth apex % [19] - - - - Tail length 60 63.2 61 75 56 Lateral guiding pieces - Absent - Present - Gubernaculum - Cresent~ - Not re- - shaped ported Spiculum - [51&66] - 60 - Supplements - 14-15 - 10-14 - []• Calculated from the original illustrations TABLE 10: Morphometric data of Granonchulus subdecurrens Coetzee. 1966 Coetzee Mulvey & Jensen Pre::lent (1966b) (1967) specimens n Holotype Paratypes 2 of':;:' 7·i-+ 7 .:f.+ L(mm) 1,1 1,0 - 1,1 1,3(1,0-1,4) 1,24(1,13-1,45) a 21 20 31(27-34) 33,0(29,7-38,1) ttl 4 4 4,3(3,8-5,0) 4.5( 4 , 3-4 , 7) c 17 16-17 22(18,2-24,5) 19,8(17,5-22,7) N c' (2,11 [2,5J 18,9(20-24) c.o - o tvi: 56 53-56 53(56-62) 57,3(56-58) Lip ';Jidth - [,0,6-23,1] [22,3] 18,9(20-24) height - [6,7-8,61 [61 7,1(6-9) Buccal cavity length - [2,2-23,51 20-21 x 20,6(19-22) width - (9,7-10,3) 10-11 x 8,1(7-9) Dorsal tooth apex % - [271 [251 22,6(19-26) Ta11 length - [52,7J 58(50-62) 62,6(60-66) - Calculated from the original illustrations x = No average given Figure 1: Mylonchulus lacustris (Cobb, N.A. in Cobb, M. V., 1915) Andrassy, 1958 A and C. Edenville specimens A. Head and neck region 8. Head region (Volksrust specimen) C. Female tail D. Reproductive system (Ladybrand specimen) E. Heat-relaxed body postures - 291 - A B E ~"~ "': " ~ : ",- s " " "" Figure 2: Mylonchulus minor (Cobb, 1893) Andrassy, 1958 A, Band F. Hhluhluwe specimens A. Head and neck region B. Head region C. Head region (Okavango specimen) D. Ventral view of vulva region (locality unknown) E. Vulva and vagina region (Umhlanga specimen) F. Reproductive system G. Intestinal cells (Augrabies specimen) H. Intestinal cells (Reddersburg specimen) I. Heat-relaxed body postures - 292 - A B c ::I: I lD E ::l o If) D E G H I c Figure 3: Mylonchulus minor (Cobb, 1893) Andrassy, 1958 Variation in female tail shape A. Edenville specimen 8. Hhluhluwe specimen c. Okavango specimen D. Augrabies specimen - 293- A B c D ,SOum A-D Figure 4: Mylonchulus sigmaturus (Cobb, 1917) Altherr,1953 A. Head and neck region (Viljoenskroon specimen) B. Head region (Pietermaritzburg specimen) C-D. Tail variaton (Okavango and Pietermaritzburg specimens) E. Reproductive system (Pretoria specimen) F. Posterior region of female (Viljoenskroon specimen) G. Heat-relaxed body postures - 294- A B c o LSQum ...JB-F F Figure 5: Mylonchulus agriculturae Coetzee, 1966 A,e and E. Hhluhluwe specimens A. Head and neck region B. Reproductive system (Clocolan specimen) C. Reproductive system D. Heat-relaxed body postures E. Female tail - 295- A B D E " mm o ,SQtJm ISQtJm A ISQtJm ---J 8 Figure 6: Mylonchulus incurvus (Cobb, 1917) Andrassy, 1958 Nelspruit specimen A. Head region B. Posterior region of female C. Reproductive system D. Heat-relaxed body postures - 296 - A B c ::-:-:..:: - ;: :.: - ;.:: .: :::: ... :.0' :=:: ::: :.. , -... '" ..... \0.~ °0" .... ::".,:n-, "0' .... D ,50um A-C Figure 7: Mylonchulus brevicaudatus (Cobb, 1917) Altherr, 1954 Paarl specimens A. Head and neck region (first specimen) 8. Reproductive system C. Female tail D. Posterior region of oesophagus (second specimen) E. Heat-relaxed body posture Clocolan specimen F. Head region G. Female tail H. Heat-relaxed body posture - 297- B c D r: .... " ::'. - :0: t- oo - "., .. -- .~: " :' - "': " - " .- ~~~ '(.'.~- . ".' ': .- .. :J~ '. - ...... :'.: .." ~':.: -- ,- ;,:: "r , .«. - ~ ~ :~~~.~ / . ::~.~ ":~ :t. '. .. -r, '.00 ',. " - !:.' ;':: ~t·~ '. - .. ~~ - ':~. .. ",; ;:. .. :'0,. -v- .' - ;~:: " ~:,~ ISOQum H .SOym S,C,F,G .soum A,D .sooum E F G ...... :; ,:.:;.,'. :.:; ...•.' :.-: H .-::.'. : ," .:::, ~ - :. : I ."t Figure 8: Mylonchulus striatus (Thorne,1924) Andrassy, 1958 Gansbaai specimen A. Head and neck region B. Posterior region of male C. Heat-relaxed body posture D. Sperm cells - 298- A B c D o c:> C> o 0 ~ o L.lli!!!!.-.. , C ,50um A.8. .25um o B c o E Figure 10: Granonchulus subdecurrens Coetzee, 1966 Omaruru specimens A. Head and neck region B. Ventral view of head region C. Female tail D. Reproductive system E. Aberrant reproductive system F. Heat-relaxed body postures - 300- A c D E G F H J ISOAJm A,B,D,E,G-I ,SOOt.lm C Figure 9: Mylonchulus species Species A from Nelspruit A. Head region 8. Female tail C. Heat-relaxed body posture Species B from Mtubatuba D. Head region E. Female tail F. Heat-relaxed body posture G. Reproductive system Species C from Ceres H. Head region I. Posterior region of male I. Heat-relaxed body posture - 299 -