A Collection of Brachionid Rotifers from Kerala by Ckg Nayar and Kkn Nair

A COLLECTION OF BRACHIONID ROTIFERS FROM KERALA

BY C. K. G. NAYAR AND K. K. N. NAIR (Department of Zoology, Christ College, Irinjalakuda) Received July 19, 1968 (Communicated by Dr. P. N. Ganapati, r.A.sc.)

ABSTRACT

The present paper, which deals with 15 species of brachionid rotifers, forms the first report on the rotifers of Kerala. A new variety Brachio- nus forficula keralaiensis has been described. Dipeuchlanis propatula, Anuraeopsis fissa lata and Brachionus caudatus personatus are reported for the first time from India.

INTRODUCTION

STUDIES on the rotifers of India have attracted the attention of a few workers (Anderson, 1889; Murray, 1906 ; Edmondson and Hutchinson, 1934; Hauer, 1936; 1937; Ahlstrom, 1940; Donner, 1949; Brehm, 1950; Pasha, 1961; George, 1961; Arora, 1962-66; Nayar, 1964-68; Wulfert 1966). Most of these works are confined to North Indian forms and our knowledge about the rotifers of South India is meagre. Edmondson and Hutchinson (1934) reported 23 species of rotifers from Nilgiri. The only other reports on the rotifers of Southern India are of Ahlstrom (1940) and Pasha (19.61) based on collections from Madras and nothing is known about the forms available in Kerala. The present paper deals with 15 species of rotifers belonging to the Family Brachionidae, collected from different localities in Kerala (Table I). Collections have been made by tow nets of nylon cloth and by washing the weeds as suggested by Gallagher (1956). Among the 15 species described in this paper one is a new variety, three are newly reported from India and nine forms are reported for the first time from South India. The list of forms collected and their occurrence in the other parts of the ¢ountr~¢ are given in Table II, 224 C. K. G. NAYAR AND K. K. N. NAIR

TABLE I

Sample No. Date of collection Locality

1 20-9- 1966 Pond Navarikulam Irinjalakuda 2 15-10-1966 Natural pond Chittur 3 29-12-I 966 Pond Manimala 4 25- 3-1967 Navarikulam Irinjalakuda

5 19- 6-1967 )) 6 8- 7-1967 College pond 7 26-- 7-1967 Navarikulam 8 20-- 8-1967 9 14- 9-1967 Pond Manimala i0 15- 9-1967 Ditch on a rock ] 1 24- 9-1967 Pond Cheruvally 12 6-12-1967 Kadalichira Alur

TABLE I[

Species = ~ ~ ."= ~ "6 ~ "'~

B. quadridentatus X .. X .... X X X X B. calyciflorus .. X .. X .. X X X X B. angularis .. X .. X .. X .. X X

B. falcatus ...... X X X X B. forficula

keralaiensis .. °° "° °" °° o° ,° ~ ,o B. caudatus personatus °" °° °q °- *° °° o.° om P. patulus .... X X X ...... P. quadricornis • . X X ......

K. tropica X .. X .. X X X X

K. procurva X ...... am X

A. fissa fissa X ...... X X

A. fissa lata "" • ..... o, o° )Q o,o

M. ventralis x x x x ...... x x T tetractis .. x x x x x ,, x ..

D. propatulus .. ,. ,, ,. ,, ,, ,, ~ .,

--indicato8 pr¢~n~e, A Collection of Brachionid Rotifers fr~ m Kerala 225

Class: ROTIFERA Subclass: MONOGONONTA Order PLOIMA Family: Brachionidae 1. Brachionus quadridentatus Hermann, 1783 This cosmopolitan species has been found to be well represented in the sampless 2, 4 and 10. The specimens collected from different localities show much variation in the length of the occipital spines. The posterior spines, which were present in all the specimens examined, were more variable than the anterior spines. The measurements of four specimens are given below: Sample 2 Sample 4 Sample 10 Total length .. 165/~ 264/~ 264/~ 294/~ Length of the lorica .. 120 150 147 144 Maximum width .. 111 183 171 186 Occipital spines .. 15, 12, 21 18, 12,30 24, 12, 42 26, 12,45 Posterior spines .. 24, 30 63, 60 81, 72 117, 117 Anterior margin .. 84 108 117 114 In all the specimens examined the lorica has been found to be pustulate. This species has a wide distribution all over India.

2. Brachionus calyciflorus Pallas, 1776 This species occurred in the samples 1 and 5. The specimens collected in September (sample 1) were not having posterolateral spines. The anterior ventral margin of the specimens in sample 5 was having a median sinus while it was arched without a sinus in the specimens of sample 1. Nayar (1968) also observed a difference in the nature of the ventral margin in the specimens collected from Rajasthan.

Measurements : Sample 1 Sample 5 Total length .. 222/~ 249/~ Length of the lorica .. 186 174 Maximum width .. 144 165 Occipital margin .. 99 123 Occipital spines .. 36, 27 45, 36 Posterior spines .. 18 12 Posterolater~l spi~ .. absent $9 226 C.K.G. NAYAR AND K. K. N. NAIR

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7' 8

Fras. 1-9. Fig. 1. Brachionus quadridentatus, Fig, 2. Braehionus forficula keralaieasis vat. nov. Fig. 3. Brachionus caudatus personatus. Fig.~ 4. Keratella procurva, Fig. 5. Anuraeopsis fissa lata. Fig. 6. Platyias patulus. Figs. 7-9. Anuraeopsis fissa fissa, Fig. 7. Ventral view. Fig. 8. Dorsal view. Fig. 9. Lateral view. (All figures except Figs. 5 and 7-9 are drawn to the same scale). This highly variable species (Nayar, 1964) is known for its cyclcmor- phosis (Nayar, 1965 ; Arora, 1966). Although this is one of the most common species of Brachionus occurring in Northern India it is of less occurrence in Kerala, perhaps due to the acidic nature of the water. It is wellknown that the distribution of the species of Brachionus is governed by the hydro- gen ion concentration of the water (Ahlstrom, 1940). 3. Brachionus angularis Gosse, 1851 A few specimens of this species were present in the sample 1 and measured 81/~ in length and 69tz in width. Berzins (1953) observed a variation in length from 79/z to 130/z in West Australia. Pejler (1957a) noticed a size variation from 90 t~ to 180 tz in Sweden while Voigt (1957) gives its length varying from 91/z to 2021z. The Indian forms of this species are relatively small arid the biggest specimen obtained from India (Baroda) ~easored only 128/~ in length (Wulfert, 1966), A Collection of Brachionid Rotifers from Kerala 227 4. Braehionusfaleatus Zacharias, 1898 This was the most common rotifer in the samples 1 and 5. This is a warm water species widespread in the tropics and a summer form in Europe.

Ahlstrom (1940) states that this species is not a highly variable species as the other species of Brachionus. Nayar (1968)has observed a variation in the length of the intermediate spines in the specimens collected from Khetri (Rajasthan). A comparison of measurements of a few specimens collected by different workers from different localities is given below: lrinjalakuda Khetri Nagpur Baroda Fesafari (Nigeria) Total length .. 351/z 369 # -- -- 197-432 t~ -- Length of the lorica .. 126 129 168 158 80-192 144 Maximum width .. 117 123 188 170 -- Occipital margin .. 84 84 .... Lateral spine .. 24 '27 28 N _ _ Intermediate spine .. 78 94 120 ------Median spine .. 24 18 .... Posterior spine .. 144 144 84 150 70--160 170

The specimens collected from Khetri (Nayar, 1968) and Nagpur (Arora, 1963) are broader than long. In the specimens from Khetri the posterior spines are smaller than the intermediate spines. Thus it is evident that this species also shows a high degree of variation especially in the size Of the torica and the length of the posterior and intelmediate spines.

5. Brachionusforficula kerala&nsis var. nov. A large number of specimens obtained from a pond at Irinjalakuda (sample 1) have been recognised as a new variety of B. forficula Wierzeiski. The lorica is firm divided into a dorsal and ventral'plate; occipital margin with six spines, laterals being the longest. The intermediate spines are very short, but invariably present in all the specimens examined: The ventral margin is rigid, elevated with a median sinus. Lorica terminates posteriorly in a pair of stout subequal spines which are widely separated at their bases; foot opening between the bases of the posterior spines. Lorica profusely stippled. The measurements of 5 specimens occurred in the same sample are given below: 228 C.K.G. NAYAR AND K. K. N. NAIR 1 2 3 4 5 Total length .. 204/~ 144 tz 213/~ 216 t~ 204 tL Length of the lorica .. 99 78 111 120 87 Maximum width .. 93 75 96 96 96 Anterior margin .. 60 60 60 60 69 Occipital spines .. 21, 3, 12 15, 3,9 18, 3, 12 18, 2, 12 Posterior spines .. 30, 28 57, 60 90, 84 96, 102

Although the present forms remarkably resemble Brachionus forficula Wierzeiski they differ from it in the presence of intermediate spines and in the absence of swellings at the base of the posterior spines. Hence this form has been recognised as a new variety of B. forficula. The present variety resembles B. t, avanaen~is and B. bidentata in the presence of six occipital spines. B. havanaensis, so far known only from North America, has the posterior spines originating very close to each other. B. bidentata differs from the present variety in having a flexible ventral margin without a median sinus.

6. Brachionus caudatus personatus Ahlstrom, 1940 This form occurred in the samples 4 and 11. In two of the specimens measured the lateral and the median occipital spines were of equal length while in others the laterals were slightly longer than the medians. In the specimens from Argentina (Ahlstrom, 1940) the laterals were found more than twice the length of the medians. Thus, as suggested by Ahlstrom (1.940) it is possible that B. mirus Daday may be an extreme form of this variety. Measurements of 4 specimens are given below: Sample 4 Sample 11 1 2 3 4 Total length .:, 150/~ 141/~ 114/~ 108 t~ Length of the lorica .. 93 87 84 78 Occipital spines .. 15, 3, 12 12, 3, 9 12, 3, 12 12, 3, 12 Posterior spines .. 39, 42 33, 33 21, 21 18, 18 Maximum width .. 84 93 75 63 Anterior margin .. 33 60 54 51

This variety, which is known so far only from the Neotropical region~ is recorded for the first time outside this region, A Collection Of, Brachionid Rotifers from Kerala 229

7. Platyiaspatulus O, F. Muller, 1788 A few specimens belonging to this species were present in the samples 1, 2, 7 and 12. The present forms agree well with the description given by Ahlstrom (1940). Measurements : Length 141-210/~; Maximum width 96-138/z. The specimens collected by Arora (1966 a) from Nagpur are much smaller in size with a body length varying from 103-110p. This is a cosmopolitan species. 8. Platyias quadricornis (Ehrenberg), 1832 A single specimen of this species obtained from Chittur measured as ollows: Total length 255/~; Length of the lorica 171 /z, Maximum width 195/z Anterior margin 102/z, Anterior spines 45/~ ; Posterior spines 45, 39/z. This species occurred along with the former species. Edmondson and Hutchinson (1934) reported this species from Srinagar and from Ladak at an altitude of 3270 m. 9. Keratella tropica (Apstein), 1907 This tropical species is distributed all over India (Edmondson and Hutchinson, 1934; Brehm, 1950; George, 1961; Nayar, 1965; Arora, 1966 a; Wulfert, 1966). The specimen collected from Manimala (sample 3) and Irinjalakuda (sample 1) measured as follows: Manimala Irinjalakuda Total length .. 210/~ 204/~ Length of the lorica .. 105 96 Maximum width .. 66 63 Occipital margin .. 54 53 Posterior margin .. 42 42 Posterior spines .. 84, 42 84, 36 10. Kerateilaprocurva (Thorpe), 1891 This species occurred only in sample 1. Measurements: Total length 117#; Length of the lorica 84 #; Maximum width 60 # ; Occipital margin 48 #; Posterior margin 37/~; Anterior spines 9, 12, 18/~; Posterior spines 18, 3 #, 230 C.K.G. NAYAR AND K. K. N. NAIP.

This species can be distinguished from the former based on the nature of the dorsal plaques on the lorica(Berzins, 1955; Nayar, 1965). In India this species is known from Rajasthan. It is probable that this species has a wide distribution all over India. \

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FJGS. 10--16. Fig. 10. Trichotria tetractis. Figs. 11-14. Dipeuehlat, is propatulus. Fig. 11. Ventral view. Fig. 12. Dorsal view. Fig. 13. Cross-section. Fig. 14. Lateral view. Fig. 15. Keratella tropiea. Fig. 16. Mytitina ventralis. (All figures are drawn tothe same scale).

11. Anuraeopsisfissafissa (Gosse), 1851 This form common in the sample 11 resembles those frcm ~et'.sied- lersee, Osterreich (Berzins, 1962) in size and shaFe. 13ut the present SlZeci- mens differ from them in having a shallow sinus at the anterior ventral margin and that the anterolateral margins of the dorsal plate are r.et so pointed. Measurement~ : Length of the dorsal plate 81 t~, Length of the ventral plate 69t~; Width of the dorsal plate 51/z; Width of the ventral plate 42tz; Anterior dorsal margin 12/z; Anterior ventral margin 56t~. This is a common form in Europe, but it is not known from Africa and North America. A Collection of Brcchior.id Rotifers from Kerala 231 12. Anuraeopsisfissa/ata Berzins, 1962 Berzins (1962) described this variety from Mekong, Cambridge. The two specimens obtained from sample 6 also have the maximum width a little in front of the posterior margin on which Berzins (1962) distinguished this variety from others. This variety is reported for the first time from India. Mea,~urements: Total length 72-78/~; Maximum width 39/~; Anterior margin 30/~; Width at the middle region 23/z.

13. Trichotria tetractis (Ehrenberg), 1830 A large number of specimens belonging to this species have been collected from sample 6. The body and the foot are heavily pustulated; toes slender and elongated. Anterior lateral margins of the lorica are pointed and spine-like. Measurements: Length of the body 159/~; Length of toes 93#. The specimens collected by Arora (1966) from Nagpur are bigger and the anterolateral margins are not pointed.

14. Dipeuchlanispropatula (Gosse), 1886 Dipeucklanis propatula is one of the two species of the genus so far known. A number of specimens of this species were present in the samples 3, 9 and 12. The shape of the specimens varied depending on the state of contraction. The dorsal plate is flat and much smaller than the ventral plate which is convex and has shallow lateral longitudinal grooves. In transverse section the ventral plate appears somewhat trilobed. The cuticle connecting the two plates is in the form of a shallow groove. The toes are slender and parallel sided. Measurements : Sample 3 Sample 9 Sample 12 Total length .. 210/~ 171/~ 258/~ Length of the dorsal plate .. 132 108 165 Length of the ventral plate .. 147 114 159 Width of the dorsal plate .. -- 51 84 Width of the ventral plate .. 117 81 132 Anterior margin .. 72 60 90 Length of the toes .. 90 66 102 This species is reported for the first time from India. 232 C.K.G. NAYAR AND ~K. K. N. NAIR

15. Mytilina ventralis (Ehrenberg), 1832 Small numbers of this species were found in the samples 7 and 8. The specimens of sample 7 are bigger than the others and have well-developed posterior dorsal spines. Measurements of two specimens, one from each sample, are given below: Sample 7 Sample 8 Total length .. 201/z 153/z Body length .... 120 Anterior spine .. 18 15 Posterior ventral spine .. 54 24 Posterior dorsal spine .. 42 0 Height of the body .. 51 51 Toe .. 60 .. This is a highly variable species in its size varying from 116 to 280~ in total length (Nayar, 1968). The posterior spines also show much variation in their degree of development. Probably this is a cyclomorphic form. ACKNOWLEDGEMENTS This work was carried out in the Research Laboratory of the Zoology Department, Christ College, Irinjalakuda. We are grateful to Rev. Fr. Gabriel, Principal, and ProL M.A. John, for their keen interest in this work. One of us (C. K. G.) is also thankful to the University Grants Commission for the award of a research grant.

REFERENCES

Ahlstrom, E. H. .. "A revision of the rotatorien genera Braehionus and Platyias with description of one new species and two new varieties," Bull. Amer. Mas. Nat. ITfist., 1940, 77, 143-84. .. "A revision of tl'le rotatorien genus Keratella with description of three new sl~ecies and five new varieties," Ibid., 1943, 80, 411-57. Anderson, H. H. .. "Notes on Indian rotifers," 3..4siat. Soc. Bengal, Calcutta, 1889, 58, 345-58. Arora, H. C. .. "Studies on Indian Rotifera~Part I," J. Zool. Soc. India, 1962, 14, 33-44. .. "Studies on Indian Rotifera--Part II," Ibid., 1963, 15, 112-21. .. "Studies on Indian R.otifera--Part V," Arch. ICydtobiol., 1966, 61, 482-93. .. "Cyclomorphosis (Form variations) in some species of Indian planktonic Rotatotia," Int. Rev. ges. ItydrobioL, 1966, 51~ 623-32. A Collection of Brachionid Rotifers from Kerala 233

Berzins, B. .. "Taxonomic und Verbreitung Keratella volga und verwandten Folmen," Arkiv. zool., 1955, 8, 549-59. .. "Revision der Gattung Anuraeopsis Lauterborn (Rotatoria)," Kungl. Fysiog. Sails, 1962, 32, 33-47. Brehm, V. .. "Freshwater fauna of India--Part lid' Rec. Ind. Mus., Calcutta, 1950, 48, 9-28. Donned, .r. .. "tIoraella brehmi, nov. gen nov. sp. ein neue Radertior Indian," Hydrobiologia den I-Iaag, 1949, 2, 134--40. Edmondson and Hutchinson • . "Report on R.otatoria, Article IX. Yale North India Expedi- tion," Memm. Conn. Acad. Arts. Sci., 1934, 10, 153-86. Gallagher, J. J. .. "Collection methods for benthic rotifers," Prec. Pennsylv. Acad. ScL, 1956, 30, 247-50. George, M. G. .. "Observations on the rotifers from shallow ponds in Delhi," Curr. Sci., 1961, 30, 268-69. Green, 3.. .. "Zooplankton of the River Sokoto. The R.otifera," Prec. zool. See. London, 1960, 135, 491-523. I-L~ucr,$. .. "Neue Rotatorien aus Indien," Zool. Anz. Leipzig, 1936, 16, 77-80. Myers, F. J. .. "" l~he Rotifer fauna of Wisconsin--V," Tran.~. Vdisc. Acad. Sci. Arts. Lett., 1930, 25, 353-413. Murray, J. .. "Some Rotifera of the Sikkim Hima)aya," J. Micr. Soc. London, 1906, 9, 637-44. Nayar, C. K. G. .. "Morphometric studies on the rotifer Brachionus calyciflorus Pallas," Curr. Sci., 1964, 33, 469-70. .. "Cyclomorphosis of Brachionus calyciflorus Pallas," Itydro- biologia, 1965, 25, 538-44. .. "Taxonomic notes on the Indian species of Keratella (Roti- fern)," Ibid., 1965, 26, 457-62. .. "Rotifer fauna of Rajasthan," Ibid., 1968, 31, 168-85. Pasha, S. M. K. .. "On a collection of freshwater rotifers from Madras," d. zooL See. India, 1961, 13, 50-55. ?ejler, B. .. "On variation and evolution in planktonic Rotifera," Zool. Bidr. Frau. Uppsala, 1957, 32, 1-66. ~tewart, F. H. .. "Rotifers and Gastrotricha from Tibet," Rec. Ind. Mus., Calcutta, 1908, 2, 316. Voigt, M. .. Botatoria : Die Radertiere Mitteleuropas, Gebruder Borntrager, Berlin, 1957. Wulfert, K. .. "Revision der Rotatorien. Gattung Platyias Harring," Limnologica, Berlin, 1965, 3, 41-64. .. "Rotatorien aus dem Stausse Ajwa end der Trinkwasset. Aubereitung der Stadt Baroda (Indien)," Ibid., 1966,4, 53-93.