Translation Series No. 594

THE I.D.LRY FISHERIES R1SEARCH gfi,D Of C/71ADA NANAIMO, C. C.

FISHERIES RESEARCH BOARD OF CANADA Translation Series No. 594

Parasite fauna of local stocks of some pelagic fishes of the Black Sea

By V. M. Nilcolaeva

TRANSLATION SERVICES CANADA INSTITUTE FOR S. NATIONAL T. I. RESEARCH COUNCIL

OTTAVM' •ANADA'

Original title: Parazitofauna lokalnykh'.stad nekotorykh pelagicheskikh ryb Chernogo moria.

From: Trudy Sevastopolskoi Biologicheskoi Stantsii, Vol. 16, pp. 387-438, 1963.

Translated by W. D. Pierce, Bureau for Translations, Foreign Languages Division, Department of the Secretary of State of Canada

Fisheries Research Board of Canada Biological Station, Nanaimo, B. C.

1965 ERTMENT OF THE SECRETAVJF STATE D'ÉTAT BUREAU FOR TRANSLATIONS BUREAU DES TRADUCTIONS

FOREIGN LANGUAGES DIVISION DES LANGUES DIVISION ÉTRANGÈRES

TRANSLATED FROM - TRADUCTION DE INTO Russian English

SUBJECT - SUJET Fish Parasites

AUTHOR •-• AUTEUR V.M. Nikolaeva • TITLE! IN ENGLISH ••• TITRE ANGLAIS The Parasites of Local Stocks of Certain Pelagic Fish of the Black Sea.

TITLE IN FOREIGN LANGUAGE - TITRE EN LANGUE ÉTRANGÉRE Parazitofauna lokarnykh stad nekotorykh pelagicheskikh ryb Chernôgo Morya

REFERENCE RdFÉRENCE (NAME OF BOOK OR PUBLICATION NOM DU LIVRE OU PUBLICATION) .Publications of The Sevastopol Biological otation (Trudy Sevastopol'skoi Biologicheskoi Stantsii)

PUBLISHER - ÉDITEUR Academy of Sciences, USSh.

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Academy of Sciences, U.S.S.R. Studies of the Sevastopol Biological Station, Vol. XVI, 1963.

The Pai'asites of Local Stocks of Certain Pelazic Fish of the Black Sea

By V.M. Nikolaeva.

The question of whether or not ,local fish 1.211 * stocks exiàt is of both theoretical and practical importance. A knowledge of local fish stocks permits • correct estimates of the quantities of various species •in a given bo.dy of water and helps to determine favourable .fishing areas.

The study of the parasites of local fish stocks is the basic problem of ecological parasitology. V.A. Dogelt and B.E. Bykhovskij initiated this type of study in 1939 when they-demonstrated differences in the parasites of Caspian Sea Sturgeon. Up to the present time, sub- - - stantial differences have been shown to exist among the parasites of local --tocks of navaga, goby, herring and floundee in the White Sea (Shultman and Shultman-Altbova, 1953) ) cod and Baltic herring in the Baltic Sea (Shultman, 1950), and Far Eastern pink salmon (Mamaev, Parukhin ) Baev,and

* Numbers in the right margin indicate the corresponding pages in the original.

• • • ■-••• 2/387

Oshmarin, 1959 and 1960). The most interesting research on the parasites of local fresh-water fish stocks has been that carried out by S.S. Shurman, Yu. N. Berenius and E.A. Zakharova (1959) at Lake Syamozero, in Karelia. In this small body of water, it was found that differences among the parasites of the local fish stocks stemmed from three factors: the varying biology of the hosts, the limited extent of their migration, and their adaptation to the shores of the lake. In salt-water bodies, there are many more such factors which are moreover closely interwoven with zoogeographical factors.

Yu. I. Polyanskij (1958 a, b), in summarizing information on the parasites of local fish stocks, noted that differences among parasites could be expressed both in their varying species composition and.in the diverse

- extent and intensity of their infestation.

Among non-U.S.S.R. studies of interest is the attempt by Sherman and Wise in 1961 to use the incidence of the parasitic entomostracan Lernaeocera branchialis L. as an indicator of the cod population off the New England coast. Cod in northern regions (off the coast of North America) have been more severely infested with this entomostracan than those in southern regions.

It must be noted, however, that parasitological data do not indicate whether local stocks of a given fish species represent isolated races* and forms ortemporary ecological groupings.

* Translator's Note: "Race in this context signifies an hereditarily distinct form, not separated geographically from the type species. 3/387-388

Very little study has so far been made of Black Sea fish

parasites from the ecological standpoint. The parasites of local Black Sea fish stocks have not been studied at all, although /338 the possible presence of local stocks of anchovy, scad and se-

veral other fish has long been suggested in ichthyological lite-

rature. In this paper the parasitological method will be used

for establishing the differences among local stocks of Black Sea pelagic fish; including the anchovy, the sprat, and the scad.

Studies of Parasites of the Anchovy Engraulls En_craSicholus Ponticus Alex,

the - Sprat Snrattqs.___SPra:nu_5_Rha1Qxj.clksL (RisSo), and the Scad Trachurus

The parasites of the Black Sea anchovy have been studied

by several investigators in a number of regions. Linstow, in

1901, was the first to demonstrate that the anchovy was infested

with parasites. In studying the helminth collection of the Zoo-

logical:Museum of-the Academy of Sciences, he described a new

species. of thorny7headed worm (acanthocephalan) Echinorhyncus

exiguus, from the Black Sea anchovy (using Chernyavskij's collec-

'tions near:Yalta). - I.M.:Isajchikov'in 1927 dissected 99 anchovy

specimens from the Kerch and Feodosiya regions.and found 17 to be infested. Of these, 14 were infested with trematodes and 7 with nematodes. The low infestation of anchovy as shown by Isajchikov

is doubtful. Males and females of Contracaecum-mulli were noted

among the nematodes. ; the species, however, was not described and

was wrongly defined, • :

• • ei•1, ■.■

4/388

.•P.V. Vlasenko in 1931 dissected four anchovy specimens from the Karadag region, but discovered no parasites. In 1938 two studies by S.V. Pigulevskij were published in which two speciés of trematodes parasitic on the Black Sea anchovy off the Crimean coast were described: Lecithaster tauricus and

Ovotrema pontica. V.N. Chulkova in 1939 investigated 15 spe- • cimens of anchovy from the Batumi region and showed that they were infested with both trematodes Lepocreadium sp. in their 1110 metacercaria in the swim bladder. - and by nematodes, including Contracaecum sp. larvae. B.E. Kurashvili and N.A. Tabidze in

1947 showed anchovy (9 specimens) in the same region to be infested with nematodes, including Porrocaecum aduncum and Porro- caecum sp.; they erred, however, in determining the generic name.

T.P. Pogorelltseva (1952a) described some new Black Sea trematodes; among them were Aphanurus virgula from the intestines of the anchovy. In another study, T.P. Pogorel'tseva (1952b) noted that anchovy were 87.7% infested with parasites and indicated seven anchovy parasite species from the Novorossijsk region; among them were Stephanostomum larvae, which were observed for the first time, and the parasitic entomostracans Ergasilus nanus and Cymothoa punctata.

A.V. Reshetnikova's dissertation of 1954 throws some light on the seasonal and age dynamics of parasites of certain commercial Black Sea fish, including the anchovy. She was the first to note an association between this species and the sporozoan Mitraspora caudata. Stephanostomum larvae, Hemiuridae sp., and

•

•••5 5/388 - 389

Cymothoa punctata are rarely found on the anchovy and attain only a low degree of infestation. Three species - Aphanurus stossichi, Ovotrema pontica, and Contracaecum aduncum larvae - are common ia for nchovy; their rate of infestation varies with the age of the fish and the season of the year.

A.S. Chernyshenko, in the 'Gulf of Odessa in 1955, discovered that 80% of 50 anchovy specimens were infested with parasites, of which 10% were trematodes and 54%, nematodes. The species of the trematodes was not indicated, but the nematodes included Contracae- cum larvae. N.A. Butskaya in 1955 noted two helminth species - likphanurus stossichi and Contracaecum aduncum - on 30 anchovy specimens from the area near the mouth of the Danube. Finally, N.M.

Wirgaritov in 1960 noted Contracaecum larvae on anchovy off the /389 coast of Bulgaria. Thus, published information indicates that parasites on the Black Sea anchovy are represented by 11 species, shown below. Synonyms are given for some species; the species or genera names for some others have been altered.

1. Mitraspora caudata Kudo, 1919. 2. Stephanostomum sp. larvae. 3. Lepocreadium sp. Tschulkova, 1939, larvae _ 4. Aphanurus stossichi 1891) Looss, 1907, syn A. Virgula Looss, 1907 5. Bacciger bacciger (Rud., 1819) Nicoll, 1914, syn Ovotrema pontica Pigulewsky, 1938 6. Lecithaster tauricus Pigulewskv, 1938 7. Hemiuridae sp. • 8. Contracaecum (E.) aduncum (Rud., 1802) Baylis, 1902 larvae

...6 • • • . '

•

6/389 . , 9. Telosentis exiguus (Linstow, 1901), syn. Echinorhynchus exiguus Linstow, 1901 • • - 10. Cymothoa punctata Uljahin, 1871 11. presilus nanus Beneden, 1870 ...

- Far less parasitological research has been carried out D1 the Black Sea sprat than.on the anchovy. The first infor-. mation on the Black Sea-Sprat - is In a"stüdy -by V.N. Chulkova,' who in 1939 examined 15. sprat specimens and discovered in them .

• • . two species of parasite. Chulkova was the first to describe a. - sexually immature form of trematode infestating 93% of sprat; her opinion, this was Didymozoon larvae. In addition,-Con- : tracaecumlarvae were observed in the body cavities of 61% of : sprat. T.P. Pogorertseva (1952b), in examining 7 sprat from . . . the Kerch and Karadag regions, noted Contracaecum aduncum on - - two of them and a low degree of infestation - 3 specimens each4 with Contracaecum larvae on the five remaining sprat. A.S. Chernyshenko in 1955 observed that 15 sprat were infested with same two species. The percentages of sprat infested with trematodes and nematodes were 73.3 and 86.6 respectively; the

.. -,.--intensity of infestation varied from 1 to 100 specimens per fish.

A. Vylkanov,, , in his catalogue of Black Sea fauna in 1957, indicated that Contracaecum' sp. (Juv.) is a sprat parasite (quo- -. ting Margaritov',s data). N.M. Margaritov also noted this species of nematode on sprat in 1960. We (Nikolaeva, 1962) redefined the larva Didymozoon as Nematobothrium sp. larvae.

No ecological studies have been made of the dynamics of 'sprat parasites as dependent upon-the age of fish, their migra- . tion and the season of the yeais. • , . • ,

; '

' ...7 7/3 89-390

Thus, only 2 species of parasite are known for the sprat: Nematobothrium, sp. larvae and Contracaecum aduncum larvae.

The parasites of the Black Sea scad have been studied in sufficient detail; reserch has also been carried out on their seasonal and age dynamics. P.V. Vlasenko was the first to study scad parasites. In 1931 he dissected 18 scad from the Karadag region, all of which were infe,ted. The percentages of scad infested with trematodes, nematodes, and acanthocephalans were 88%, 39%, and 33% respectively. Of the trematodes on sprat, the following were described: Tergestia laticollis, T.sp., Haplocladus tvpicus, Ancylocladium typicum, Leporeadium sp., and Ectenurus lepidus-(?). V.N. Chulkova in 1939 examined 14 scad from the Batumi region- and noted that they were 1005 infested; the percentages of infestation with trematodes and nematodes were 505*a and 100% respectively. Chulkova was the first to observe Galacto- somum sp., Contracaecum sp., and Scolex polymornhus. S.U. Osmanov, who, in 1940, studied 15 sprat specimens from the Sevastopol' re- /390 gion, also observed the extent to which each was infested. He found 9 species of parasites, including, for the first time, the following: Stephanostomum sp., Pharingora poloni, Aponurus tschu- Eunozi, and Echinorhynchus propinguùs.B.E. Kurashvili and N.A. Tabidze in 1947 also - discovered, on scad, nematodes whose species they wrongly defined as Porrocaecum adunca. In 1949 there appeared a study by A.S. Chernyshenko in which new Black Sea helminth species were described, including Lepocreadium retrusum on scad.

• T.P. Pogorertseva contributed substantially to the study of scad parasites. In 1952, three of her works onfish parasites of the northeastern Black Sea were published. •She noted the less

. 8 8/390

varied species Composition of scad parasites from the Kerch region as compared with. Karadag and Novorossijsk; this phe- noMenon resulted from the freshening by the Sea of Azov of the watér around Kerch. In one of T.P. Pogoreworks (1952a) the species Lepocreadium sp. was incorrectly defined; in 1954 Pogoreltseva redefined it as a new species - Plagioporus trachuri. Pogorelltseva found 17 parasite species on the scad, including, for the first time, the following: Didymozoon larvae, Telosentis exiguus, Contracaecum clavatum, Cucullanellis minuttÀ, Cymothoa punctata, and Gnathia sp. These species attacked 94.1% .of 68 fish examined.

A.V. Reshetnikovaj in 1954/ examined two forms of scad, 1 "Black Sea" and "Sea of Marmora". She studied the age dynamics of parasites on the Black Sea scad and discovered 8 species of trematode, including,- for the first time, the following: Helico- metra nulchella, Opechona st.., and the sporozoan Chloromyxum E112..sIntjulli. Only 2 trematode species - Helicometra pulchella and Stephanostomum larvae - were found on the "Sea of Marmora" scad. Furthermore, three parasite species of other classes, including Ergasilus sieboldi, noted for the first time, proved to be common to both forms of scad. A.V. Reshetnikova attributed the scarcity of parasites on "sèa of Marmora" scad to the fact that this form had only recently begun to inhabit the Black Sea.

A.S. Chernyshenko, in the Gulf of Odessa in 1955, observed that all of 30 scad specimens were infested with parasites; she observed Aphanurus stossichi and Tetrarynchobothrium larvae - for

1 "Sea of Marmora" is a term applied by A.V. Reshetnikova to the "large" form of Black Sea scads.

...9 9/390- 391

the first time. A.V. Vylkanov 1n1955 noted Contracaecum aduncum on scad off the coast of Bulgaria. K.V. Smirnova, in Novo- rossijsk Bay in 1957, found, on the scad, only three species of parasite which were common for this fish.

T.P. Pogorelltseva,in 1959revea1ed the seasonal and age dynamics of scad parasites throUgh a study of 238 specimens. Ini- tial discovery was made of only one species - Hemiurus sp. Of the scad underyearlings, 20.7% were infested with sexually immature forms of digenetic trematodes and nematodes. Of the yearlings, 37.7% were infested to a low degree with 6 species of parasite. Seventy-six per cent of scad from the ages of 4 to 6 years were infested with 11 species of parasite; 34.6% of those from 7 to 9 years of age were infested with seven parasite species. Pogorelitseva divided all parasites into three groups: those which attacked fish of all ages, those attacking middle-aged fish, and those which diminished (in numberj with the age of the fish. The widest species diversity of scad parasites occurs in spring. At this time, infestation with several digenetic trematodes takes /391 place; included among these are Lepocreadium retrusum, Ancylocoe- lium typicum and Stephanostomum larvae. At the end of the summer, in the autumn, or at the beginning of winter, the trematodes finish producing their eggs and die. The smallest species composition of parasites is observed in winter.

N.M. Margaritov, in 1960 off the coast of Bulgaria, noted four species of parasite on the scad; of these,three were corimon for it and one - Lecithocladium exisum - had appeared only recently. 'Published data, then, lists 26 species of parasite for the Black Sea scad as follows:

...10 10-391

1. Chloromyxum guadratum Thelohan. , 1895 2. Galactosomum sp. larvae 3. Stephanostomum sp. larvae 4. 1 Nematobothrium sp. (Tschulkova, 1939), syn. Didymozoon larvae 5. Ancylocoelium typicum Nicoll, 1912

6. Aphanurus stossichi (Monticelli, 1891) Looss, 1907, syn. A. Virgula 7. Aponurusitschugunovi Jssaitsch., 1927 8. Ectenurus lepidus Looss, 1907

9. Haplocladus typicus Odhner, 1911

10. Helicometra pulchella (Rud., 1819), Odhner, 1902

11. Lecitecladium excisum (Rud., 1819), Lillie, 1801

12. Lepocreadium retrusum Linton, 1940.

13. Plagioporus trachuri Pogorelzeva, 1952

14. Tergestia laticollis Rud., 1819 15. Opechona sp. (neescription of species)

16. Hemiurus sp. (no description of species)

17. Scolex pleuronectis Millier, 1888, 18. Tetrarynchobothrium sp. larvae

19. Acantocephaloides kostylewi (Meyer, 1933) 20. Tèlosentis exiguus (Linstow, 1901) 21. Contracaecum (E.) aduncum (Rud e 1802), syn. Contracaecum clavatum (Rud. 1809) 22. Contracaecum sp. larvae 23. Cucullanellus minutus (Rud., 1819) 24. Gnathia sp. 1 • 1i 25. Ergasilus sieboldi Nordmann, 1832 . 1 i 26. Cymothoà punctata Uljanin, 1871, swiLivoneca pontica Borcea 1931 i / ) ›

.4-11 t•-

Materials and Methods

Material for the study of the parasites of Black Sea anchovy, sprat, and scad were collected from 1958 to 1961 in various regions of the Black Sea. Parasitological research on these fish was carried out in the laboratory of the expedi- tionary vessel Academician Kovalevskij, a ship belonging to the Azov-Black Sea Scientific Research Institute of Ocean Fisheries and Oceanography, at the Batumi Fish Combine, and in the laboratory of the Sevastopol Biological Station. A total of 309 fish specimens were examined, including 88 anchovy, 77 sprat,

and 144 scad.

For an adequate description of the parasites of individual fish stocks, no less than 15 to 25 specimens from each stock had to be examined. It was essential that fish of the same age be examined in the same season. The parasites of local fish stocks were analyzed only when the stocks were most widely separated and mixing was at a minimum. The separation of such pelagic fish as anchovy and scad was observed in autumn, most notably in /392 winter, and in spring. Our research was carried out principally during these three seasons.

All of the fish which were examined were submitted to a full parasitological analysis in accordance with standard methods. The blood was not always examined, since, in dead fish extracted from several fishing devices, it had already coagulated and it was impossible to take smears. The parasites were fixed and stored in accordance with the standard methods.

. . .12 12/392

A complete description of the Black Sea anchovy which were examined is shown in Table 1, which indicates the areas from which the samples were taken, the type of fishing equipment used, the season in which the examinations were carried out,.the quantity of material investigated, sizes, and weights. A few instances where the average weights and sizes of 2 and 3- year old anchovy caught off the Crimean and Caucasus coasts were below average resulted from the presence Of One 'two underyearlings in each sample.

In addition to full parasitological dissections carried out in the summer of 1959 and the autumns of 1960 and 1961, supplementary dissections were also carried out. At the same time, parasites (usually trematodes in the metacercaria stage) were removed once from several fish specimens in order to set up the experiments described below. Frequently, all the organs of the fish which had been additionally dissected were than examined. Thus 70 anchovy specimens and 81 scads were additionally studied.

The parasites of the Black Sea sprat were studied mainly from six open areas . of the sea (Table 2), many of which were close to each other. Sprat were examined in winter, spring, and summer; in this way, the basis for the seasonal dynamics of the parasites was defined. All of the fish which were examined were sexually mature, and could be classed among the autumnal commercial.group of 2 to 3-year olds. In this way, the age factor was excluded.

The parasites of the "small" Black Sea scad were studied fi-Om' three areas of the Sea (Table 3). The seasonal dynamics of the parasites were investigated using the Crimean stocks of this 13/395-396

fish as an example. Other stocks were studied at various seasons, but compensation could always be made for the seasonal factor when comparisons were being drawn with the Crimean stock. All of theinsmall" scad were sexually mature and were represented by common commercial yearlings and 2-year-old fish.

The influence of age on the parasites of the scad which were examined was excluded when the material was selected.

The parasites of the "large" Black Sea scad, i.e. scad • from the southern stock, were Studied in summer (see Table 3)

. Scad ranging in age from 9 to 12 years were examined.

' The parasites of the Black Sea anchovy Enraulis encrasicholus ponticus Alex consist of 13 species, of which we noted • 9 previously and are listing 4 for the first time. Of 88 fish which were examined, only 2 small specimens were found to be free frarl:Prasites-(see Table 4). The intensity of infestation was very high - an average of 74 parasites (from 1 to 476 per fish).

We did not find Telosentis exiguus among the anchovy parasites - which were noted earlier. Acanthocephalans are evidently vary . rarely found on anchovy. We did not examine anchovy from the Novorossijsk region, where an isopod was noted earlier.

The following species were noted on anchovy for the first /396 time: Nematobothrium sp. larvae l Pentagramma symmetricum, Lepo-

creadium retrusum, and Pseudoanthocotvle sp. The metacercària of Stephanostomum was visually defined as S.pristis, and larvae of

1 .

...14 14/396-397

Lepocreadium sp. from the swim bladder of the anchovy were redefined as Lecithochiridae gen. sp. larvae. Hemiuridae sp., which was noted previously in the stomach of the anchovy, was defined as Hemiurius communis.

The anchovy were infested mainly by helminths, including 9 Species of Trematoda, one species of Monogenodeà, and one species, of Nematoda. It was also noted that helminths produced the highest _ intensity of infestation. - •

The parasites of the Black Sea sprat Sprattus sprattus phalericus (Risso) were represented by three species (see Table 5). No fish were found to be free from parasites. -The intensity of /397 infestation, i.e. the quantity of parasites of all species on one fish, was also high, averaging 46 (from 2 to 213).

Two species of the sprat parasites which were noted had been known, previously, while we found larval forms of trematodes of the genus Stephanostomum for the first time. In addition, a single sea tick (Halacarae) was found in the winter on two occasions in the - region of Karkinit Gulf and off the south coast of Crimea on the gills of sprat. This small nymph. probably belonged to the subfamily Halacarinae of the genus Copidognathus Trouessart (Sokolov, 1952). The tick was retained on the gills and was taken into the mouth, - cavity with food. In winter, off the southern Crimean coast, about , 80 vary small infusorians were disclosed on the gill filaments of sprat. The species, however, could not be determined because of incomplete fixation.

A peculiar characteristic of sprat parasites is that only the, larval forms are parasitic.

...15 15/397-398

A total of 13 species of parasites feed on the "small" Black Sea scad, i.e. those from southwestern, northern, and eastern stocks - Trachurus mediterraneus ponticus Aleev. Of 127 fish which were examined, only 6 were found to be free from • parasites (Table 6). The intensity of infestation amounted to an average of 38 parasites per fish (from 1 to 253).

Almost all of the parasites found on th? "small" scad had been associated with it previously. It was uncharacteristic of the scad that larvae of Tetracotyle sp., a common pickerel parasite, were found in its brain. The infestation of the scadts intestines with nematode larvae also appears to have been accidental. Four scad were infested with these larvae in winter in the Crimea region. The larvae were very small and encysted on the wall of the intestines. The intensity of infestation was high, varying from 50 to • 100 csysts. • /398 In addition, a mass of very small infusorians was discovered k on one occasion in autumn on the gills of scad. A defect in fixation made them difficult to define. Hyperaemia of the gill filaments is frequently observed on scad in winter. This phenomenon was observed on scad five times in the Caucasus region and four times off the Crimean coast. On individual fish, only a few adr joining gill filaments were affected by hyperaemia, while on others, all gill filaments were severely affected, although no parasites were disclosed.

A total of 11 parasite species were found mi the "large" Black Sea scad, i.e. scad from the'southern stock (see Table 7). Of the "large" scad parasites noted by A.V. Reshetnikova,two species'

...16 • 16/398-399

were found; nine other species were rioted on scad for the first time. Such an abundance of parasite species found for the first time indicates that very little study has been made of the parasites of the "large" scad. It would be extremely interesting to (1) study the age dynamics of the parasites of the "large" scad.

On the gills of a "large" sdad caught in the Sevastopol region were found three specimens of Spirorbis (of the Polychaeta 1 .class). This sedentary form of polychaetous worm usually settles on the shells of mollusks and on the carapaces of crabs, but had not previously been noted on fish gills. .

A total of 17 species of parasites was noted on all four stocks of scad. Almost all species found on the "large" scad were also found on the "small" scad. The trematode Synaptobothrium caudiporum was noted on scad for the first time. Acanthocephalans were absent from previously known scad paraites in our material: crustacea were represented by only one species. Representatives of both these classes were noted previously on scad from the Karadag- Novorossijsk region. The Karadag region is very rich in inverte- /399 brate fauna. The wealth of intermediate hosts in this area is creating a persistent infestation of fish by acanthocephalans. : The development cycle of acanthocephalans on scad has so far not -- been studied; it may only be assumed that crustaceans3 which are evidently rarer in the bays of the Sevastopol region, serve as intermediate hosts. In the Novorossijbk region, parasitic crustaceans

(1) An investigation of this type was carried out from 1961 1962 by A.A. Kovaleva at the Karadag Biological Station. 17/399

are also found on anchovy, but much more frequently and with a greater species composition than in other areas of the sea.

The Morphology and Species Composition of Disclosed Parasites.

Class: Snorozoa Branch: Myxosporidia Myxosporidia gen. sp. Host: Black Sea anchovy Lobalization: kidneys

• A representative of the order Sporozoa was found only in the vegetative - stage in the kidneys of one anchovy caught in Janu- ary off the Caucasus coast. Twenty-five cysts were found. The cysts were oval in form and measured, on the average, 0.212 by 0.139 mm. (from 0.177 by 0.124 mm to 0.270 by 0.146 mm). •

It is possible that the absence of spores, which would enable this species to be defined, was related to the disclosure of this parasite in winter. Thus, Mitraspora caudata cysts on , the Azov anchovy in spring (Nikolaeva, 1951) contained more than 100 spores, although the cysts themselves were round and small.

Class: Trematoda Larvae

When trematodes were being processed in their larval stages, it was still not clear to what species they belonged. In some cases, there was difficulty in determining the species of metacercaria (Stephanostomum, in all fish which were examined); in other instances, even the definition of the genus of helminths was doubtful (Lepocreadium sp.c from the swim bladder of the anchovy).

.. .18 18/399-400

I.E. Bykhovskaya-Pavlovskaya and G.K. Petrushevskij (1959), in describing the larvae of fish trematodes, noted that the method of experimental infestations was the basic means of defining this group. To establish the species of the metacèrcaria which were discovered, we set up 24 experiments. In outline, the experiments were as follows: after the species of a metacercaria was first defined and the definitive hosts examined, the experiment got under way with the infestation of as many hosts as possible. The metacercaria were removed from their areas of localization on fish • which were still alive; at the same time, every attempt was made to keep injuries of their cysts and the surrounding tissue of the hosts to a minimum. The .irietacercaria were recounted, placed in sea water, and then introduced by a pipette into the gullet of the fish in the experiment. Sometimes the metacercaria were not removed from the affected organ, but were introduced into the gullets of the fish together with the organ by pincer. The fish in the experim.ent were kept from 1 to 41 days. Simultaneously with the experiment, some of the fish which were included were dissected to determine the "background" of their infestation. During the experiment, the fish were kept in aquaria supplied with constantly /400 changing sea water. -Occasionally, the fish were not fed, and, if the experiment was prolonged, the fish were fed with mussel meat, which did not alter the character of their infestation. At the end of the experiment, a full parasitological dissection of all fish was undertaken. It was, as a rule, very easy to distinguish between naturally and artificially introduced fish parasites (i.e. .those intrOduced during the experiment), since; while the eXperiment was being carried out, a series of transitional forms was observed which changed from metacercaria into sexually mature forms. In

...19

• 1 • 19/400

individual instances, fish were infested which were not the terminal hosts of these parasite species. The negative experimental results which were obtained in this way indirectly confirmed the correctness of preliminary definitions.

The detailed content of the experiments and the resùlts obtained were set forth when the 'species of metacercaria used in the experiments . were described.

_ Didymozoidae (Monticelli, 1888) Poche, 1907

Nemtobothrium SD. (Tschulkova, 1939) Nicolaeva, 1962 Host: sprat, anchovy and scad ("small") Localization: liver and (less frequently) gills

We have previously described (Nikolaeva, 1962) the metacercaria parasitic on sprat.

The parasitic action of this very original trematode metacercaria on anchovy was noted for the first time. Anchovy were very lightly infested with this parasite. Thus, of 88 small fish from various sea areas, only 3 were found to be infested. The intensity of infestation was also very low - only 1 to 2 metacercaria per fish.

The metacercaria attained an average size of 1.065 mm. (from 0.915 to 1.215 mm) with a maximum body width of 0.177 mm (from 0.093 to 0.239 mm). The mouth sucker was in the shape of an elongated oval, measuring 0.075 by 0.031'mm. The ventral sucker was on a pedicle and measured 0.075 by 0.058 mm. The distance between the suckers was on the average 0.111 mm (from 0.075 to 0.146 mm) and on more than 10 occasionezas situated within the standard length of the metacercaria.

...20 20/400

The gullet led to the intestine, which filled the entire body of the metacercaria. The intestine formed 2 series of chambers, of which the rear, numbering between 8 and 10,were very large and clearly visible.

Metacercaria from anchovy, both in their morpnology and in their size, very closely resemble the metacercaria of Didymo- zoonidae, which are parasitic on Black Sea sprat, apd are classed among the same genus, and, possibly, the same species. They are much smaller and less active on the anchovy than on the sprat.

. The appearance of metacercaria in the anchovy must be considered as accidental, and was not characteristic of the usual development cycle of this species.of parasite. -

The larvae of Didymozoonidae, which were parasitic on "small" black sea scad, fully corresponded.in their morphology ' to those described for sprat. The metacercaria attained a length of 1.410 mm and a maximum breadth of 0.136 mm. The mouth sucker was long and oval in shape, measuring 0.062 by 0.037 mm, while the ventral sucker measured 0.068 by 0.056 mm. The distance between the suckers was 0.130. mm, or one-eleventh of the length of the body.

The very characteriStic structure of the intestinal branches and the 12 large clearlY visible chambers Should be noted.'

Metacercariae were found very rarely on scad. One infested fish was caught off the Southern Crimean coast (at Solnechnogorsk), and the other, off, the Caucasus coast, with an infestation intensity of 1 to 5 specimens per fish.

.")1 21/401

Family: Acanthocolpidae Ldhe, 1909 (Deslongchamps, 1824) Stephanostomum pristis Looss, 1889 Larvae

Host: Black Sea anchovy Localization: gills

The anchovy is a- second intermediate (or in Skryabin's opinion ofl 1954, supplementary) host of this species. The metacercaria which were parasitic on the anchovy were usually localized in the muscles .and epithelium of the gill chamber, primarily the gill arches, and, as an exception, in the muscle of the heart -and other organs. The cysts were round, measuring 0.550 by 0.600 mm. The larger cysts attained a-size of 0.870 by 0.600 mm; smaller ones measured 0.420 by 0.445 mm. If the cysts did not occur in their normal places of localization, they were usually very small • • and the metacercaria was almost unformed. Thus, on one anchovy, fully formed metacercariae were Aisclosed on the gills; in the testes, the cysts were. much smaller (0.285 by 0.255 mm), with an almost undeveloped metacercaria, while in thelaall of the stomach

there was found a mass of even smaller cysts (from 0.084 by 0.081 to 0.150 by 0.150 mm); it was, however, difficult to determine the • speCies of the latter.

All cysts had a two-layer membrane; the outer membrane was fatter, and the inner one thinner. The outer diameter of the cysts was 0.300 by 0.350 mm and, of the largest, 0.510 by 0.405 mm. Wi- thin the cyst was a double-folded metacercaria from 1.050 to 2.250 mm in length and varying in width from 0.130 to 0.180 mm at its forward end to a maximum of 0.288 to 0.450 mm (see fig. 1). Thirty- six spines were situated around the mouth sucker. The spines were

...22 22/401 -402

arranged in two rows: in the upper row, the length of the spines varied from 0.037 to 0.053 mm, while in the lower rowitvaried from 0.031 to 0.043 mm; the dorsal spines were larger then the ventral spines. The mouth sucker was somewhat smaller than the ventral sucker; its measurements varied from 0.155 to 0.165 mm (0.130 mm on the average) by 0.093 to 0.124 mm. The ventral sucRer was spherical and between 0.170 and 0.195 mm in diameter (the average AM' 11, I -- diameter was 0.180 mm). It was situated below the bifurcation in the intestine àt a distance of 0.840 mm from the forward end. The cuticle was covered with small prickles, which were easily visible immediately behind the mouth sucker, and were almost indis- cernible beyond the bifurcation of the intestine. The ratio of suckel7's was 1 : 1.4. Two pigmentary eyelets lay along both sides of the pharynx, one slightly higher than the other.

The prepharynx was long (from 0.155 to 0.465 mm), while the pharynx measured from 0.031 by 0.028 mm to 0.136 bY 0.105 mm. The short and the intestinal tubes were long, exten- ..-- gullet was very ding to the.hindmost_portion of the body, where they tended to converge.

- The metacercariae in the cysts were.in various stages of deVelopment, and in pnly a few'of them could structural details be examined. The characteristic black spot which was clearly visible within a milky -white cyst made this genus very easily distin- /402 guishable from the metacercariae of_trematodes of other genera . This pigmentary spot became somewhat reduced and in fully formed metacercariae was retained in the rear portion of the body. On the largest metacercariae, it measured as much as 0.315 by 0.225 mm.

• • • „

23/402

These were embryo sex organs which were closely situated. In the lower part, the testes were somewhat isolated; the yolk sacs and the ovary were not clearly evident.

The maritae of Stephano,stomum pristis are parasitic on various representatives of the cod family, and, in the Black Sea, on the Black Sea whiting, or Odontogadus merlangus euxinus (Uor- dmann). Anchovy are common prey of the Black Sea whiting.

Netacercaria from anchovy, in the same way as S. Pristisb are defined on the basis of the number of their spines and their sizes and ratio, and sucker sizes. All the indicators which have been given for metacercaria fully correspond to those for the marita of S.pristis; the fact that Black Sea whiting feed on anchovy makes a similar development cycle possible.

Host: sprat Localization: gill chamber

Sprat was noted for the first time as a secondary intermediate (supplementary, in Skryabin's opinion) host for trematodes of this genus. The .cysts were round, measuring from 0.435 by 0.555 to 0.495 by 0.615 mm. The c.yst wall was not thick, measuring only 0.012 mm. The size of the metacercaria in the cyst was 0.420 by 0.330 mm. The mouth sucker measured 0.096 by 0. 01 mm. Around the mouth sucker in two rows lay 32 spines (some of them possibly underdeveloped). In the upper row, they were 0.030 mm in length, and, n the lower, 0.022 mm. The pharynx measured 0.093 by 0.062 mm. The metacercariae which were parasitic on sprat were very small and probably did not attain the usual size of the

.. .24 24/402-404 species when it is parasitic on other fish serving commonly as its intermediate hosts. It has therefore been impossible, so far, to define this species.

Stephanostomum cesticillum (Mollin, 1858):Looss, 1899 larvae Host: Black Sea scad ("small" and "large") Localization: gill chamber muscles; less frequently, the pharynx and the gullet.

Like the anchovy and the sprat, the scad is a secondary intermediate (supplementary, in Skryabints opinion) host of this species. Stephanostomum metacercariae have been disclosed on the "small" and "large" scad in all regions of the Black Sea. A study of the morphological indicators of metacercariae (see table • 8) found in various regions of the sea has led to the conclusion that one species is parasitic on scad. The membrane of the cyst was always two-layered. The thickness of the first layer varied from 0.010 to 0.180 mm. The second layer was usually more compact, but was not fat; its thickness varied from 0.005 to 0.012 mm (see fig. 2). The metacercariae, in a one and one-half or double fold, was closely attached to the second inner layer of the cyst. An attempt has ben made to define this species on the basis of indicators which are characteristic of other metacercariae (the number - of spines, their sizes, and the ratio and sizes of their suckers).

The number of spines varied from 33 to 36; they were situated in two rows, of which the first was much larger than the second. The suckers were small; the ratio between them was 1 : 1.2 to 1.3. In tile autumn of 1960 a live metacercaria taken from a cyst on a /404 "small" sprat was studied. It was 3 mm in length; the mouth sucxer

...2 5 25/404

measured 0.233 by 0.161 mm and the ventral sucker 0.273 by 0.279 mm, i.e. the ratio between them was 1 : 1.2. The mouth sucker had 34 spines (17 in each row) measuring 0.067 ram (from 0.062 to 0.071 mm) • in the first row and 0.053 ram (from 0.044 to 0.059 ram) in the second.

When the sizes of live and fixed metacercariae are compared, it becomes evident that the latter are much smaller, since their bodies, and particularly their suckers, shrink to a considerable extent during fixation. The relationship among the organs, howelier,

remains the same. Four marita species of the âenus Stenhanostomum were disclosed on Black Sea fish. Of these, Stephanostomum bicoro- natum and S.minutum had a mouth sucker which was twice as small

. as the ventral sucker. stErispis had small suckers; the mouth sucker measured 0.13 mm and the ventral, 0.19 mm; the ratio between them was 1 : 1.5. The suckers on the Stephanostomum metacercariae from scad were much larger than on S.pristis. The largest suckers on the fixed specimens were the mouth, measuring 0.186 mm and the ventral, measuring 0.211 mm; on a live metacercaria, these sizes were even larger. The difference in sucker sizes was not great, with a ratio of 1 : 1.2. This sucker size ratio is observed on only. one Black Sea species of S.cesticillum, which is parasitic on the goosefish. — Although this species is typical of the genus, it has been incompletely described and studied. Its characteristic feature is the presence of 35 to 36 head spines (the rear spines are smaller than the anterior spines). The mouth sucker measures 0.4 mm and the ventral sucker, 0.48 mm, i.e. the ratio between them is 1 : 1.2. The specimen under study had similar large suckers measuring 12.5 mm. It is fully evident that the growth of the

...26 26/404 - 405

suckers keeps pace with that of the metacercaria; in this case the ratio between them is characteristic.

The goosefish, a terminal.host of this parasite, is very seldom found in the Black Sea. The scad is included among its prey, but it is difficult to imagine that the large scad - a . very swift pelagic fish - - could'be caught by the goosefish. Nonetheless metacercariae were found on scad in huge numbers, averaging 426 specimens per fish (from 156 to 710). A series of experiments was set up to define metacercariae from scad. We . did not succeed in catching a goosefish for the experiments, since it is too rare in the Sevastopol region. The experiments included all hosts except the goosefish, on ,which Stephanostomum maritae are . parasitice the whiting, the slab, and the stargazer. In not one of the above hosts did . the metacercariae develop and attain a sexually mature form, indirect confirmation that this species has.been correctly defined, i.e.) these hosts were not Specific for metacercariae from scad (see table 9) . .

It may be assumed from trophic associations that the terminal host for Stephanostomum larvae, which are parasitic on scad, is the pelamid, since, according to Tikhonov, it frequently feeds on "large" scad. No Stephanostomum maritae have so far been disclosed on pelamid. /405 Trematoda gen. sp. larvae

Host: Black 5 scad ("large"). Localization: .intestines

No parasite action by larval forms of trematodes has been noted on "large" scad. Large, oval-shaped cysts, measuring frOm

...27 27/405 - 406

0.233 by 0.186 to 0.279 by 0.217 mm., and surrounded by a compact membrane, were found to be fastened to the wall of the intestines. When the cyst membrane was scraped off, the host tisSue always remained attached . to it, giving the cyst a "rag- ged" appearance and large dimensions - from 0.264 by 0.264 to 0 4434 by 0.363 mm. The internal diameter of the cyst varied frOm 0.186 by 0.161 to 0.217 by 0.186 mm. The metacercaria lying within the cyst came into very close contact with the cyst membrane. Within _ the metacercaria it was possible to observe a sucker measuring from 0.133 by 0.059 to 0.112 by 0.127 mm and a cavity (?) measuring 0.177 by 0.053 mm. Some threads were visible on the mem- brane_of one of the cysts. It is possible that these threads represented larvae of the order SI..E1gmta...

Tetracotyle sp. larvae Host: scad ("small") ' Lo'calization: brain

Metacercariae of this species are usually parasitic on pickerel. This parasite was observed on pickerel on only one occasion. Infestation with this parasite is not characteristic of pickerel.

Family: Lecithochiridae nrjabin t Guschanka, 1954

Lecithochiridae gen. SD. larvae Host: Black Sea scad Localization: swim bladder .

This speCies, which was defined by B.E. Bykhovskij as Lenocreadium sp, larvae, was noted on. anchovy by V.N. Chulkova'in

.. .28 1 • 28/406

1939 in the Batumi region; here, it infested 5020 of the specimens examined, while the intensity of infestation varied from 2 to 6 specimens per fish. The same species was noted by T.P. Pogorel'tseva at Novorossijsk, where the rate of infestation of specimens examined was 5% and the intensity varied from 1 to 3 parasites per fish. ' /406 Observations of live trematocles from the swim bladder of the anchovy have raised some doubts as to whether this genus was correctly defined by V.N. Chulkova and T.P. Pogorertseva. This parasite has been found very rarely on two-year-old and three-year- old anchovy; only when additional dissections were made on anchovy in the fall of 1961 was the species observed very frequently. A -four-yearold anchovy caught in the Sevastopol region was additionally dissected for experimental purposes. An analysis of anchovy of this age group has shown that this parasite is found frequently (oh ueo 65% of specimens examined) and in large quantities (from 1 to 73 specimens per fish). Hence this species is characteristic .02 old fish. It is worth noting that the sizes of the young forms of trematodes which were examined coincided basically with those which were referred.to by V.N. Chulkova; undoubtedly, one and the same species was examined (see table 10).

It was observed in some large fish specimens that parasites had moved into the sex organs and that the shape of their (the parasites') bodies had altered. The trematodes became more tapered, the rear end of the body became extended and a drawn-in tail apen- dage appeared (see fig. 3). The cuticle was slightly annular; this annulation was clearly visible below the ventral sucker, where

...2 9 29/406-407 408 large folds of cuticle usually occur. The excretory system was . particularly noticeable on live trematodes. Its tubes united in the region of the pharynx and separated at the lower edge of the ventral sucker. The mouth sucker was situated subterminally and lay ventrally. Above it, the muscle fillet of the forward lip was well developed, occasionally widening on the lower edge of the sucker. The gullet was short and the intestinal tubeÈ /407 extendeditowards the rear end of the body, but did not however, reach this end. The sex orifice was situated between the mouth and ventral suckers. The seminal vesicle was divided into three portions. Two testes lay immediately beneath the ventral sucker. They were oval in shape, measuring 0.093 by 0.062 and 0.087 by 0.071 mm. The ovary, measuring 0.062 by 0.040 mm, lay a conside- - rable distance below the testes. The yolk sacs began to develop immediately beneath the ovary; at first they were flat, and then digitate lobes developed. The first eggs appeared in the uterus, but were still unformed. It must once more be stressed that the reproductive system of these trematodes was only in its initial stages of development. As trematodes grow, it is possible that both the dimensiems and the shape of their organs change.

.A series of experiments was also set up to det-e-rmine trematodes of this genus (see table

/408 As .may be seen from the table, very few whiting survived the experiment, owing to the high temperature of the water in the acua- ria. In only two instances on the third day were the helminths with which the group of whittfish had been infested found in their stomachs. Among the slabs, which withstood all the expements well, six specimens of Lecithochiridae gen.sp. larvae (Skryabin, 1955)

...30 3 0/408

were found in the stomach after 20 days; these represented of the parasites with which the fish had originally been infested. Morphological data on the forms which were disclosed are given in table 12.

A comparison of these trematodes with the young forms which were found in the swim bladder of the anchovy has shown that they represented One and the same species. Almost no trematodes developed in the slab over a period of 20 days, since this group of fish was probably not a terminal host of this species of trematode. A study of the trematodes developing on whiting and slab during the experiment confirmed once more that V.N. Chulkova and T.P. Pogorelttsevd were mistaken in defining larvae from the swim blad- -, der 6f the anchovy as Lepocreadium .sp. larvae.

Maritae Family: Hemiuridae Lillie, 1901 Hemiurus (Hemiurus) communis Odhner, 1905 Host: Black Sea anchovy Localization: stomach

_ In 1954 A.V. Reshetnikova noted that sexually immature forms

of hemiuridae SD. were parasitic on anchovy; this parasite, however, was rarely encountered and its intensity of infestation was low.

In the summer, we found 107 specimens of hemiurids in the stomach, irltestines and pyloric appendages of anchovy. Most of the trematodes were sexually immature, but in some, the reproductive system was already fully developed and the uterus was filled with eggs with a developing metacercaria. Using these specimens, we wete also able to determine the species of helminth. The hemiurids

...31 3 1/408

were (on the average) 0.705 mm in length (from 0.485 to 0.88 mm), while their maximum body width was (on the average) 0.110 mm (from 0.099 to 0.140 mm). Their tail appendage made up one third of their body length. The tail sucker was spherical, measuring 0.051 by 0.045 mm. (from 0.041 by 0.037 to 0.054 by 0.052 mm); the ventral sucker measured 0.094 by 0.083 mM (from 0.084 by 0.072 to 0.109 by 0.093 mm); their size ratio was 1 : 2. The pharynx was large, measuring 0.03]i. by 0.025 mm. The intestines extended one-third of the way into the tail appendage.

The testes measured 0.062 by 0.053 and 0.062 by 0.065 mm. The ovary' was round, measuring about 0.060 mm in diameter; the eggs measlired 0.022 by 0.012 mm.

We shall supply no morphological details or illustration, since the herliurids which we disclosed correspond fully to H.(ti.) communis. This species is widely distributed among many fish species in several oceans, although it has not previously been observed on anchovy. The specimens which we discovered were somewhat smaller than those described by Odner, but in size they re- sembled the hemiurids which were discovered by T.P. Pogorelltseva in 1952 on the Black Sea whiting.

The anchovy_is, most probably, a chance host for this species of parasite, since it is not essential to the parasite's development cycle. Trematodes entering anchovy canrot only become acclimatized, but can also attain sexual rriturity and still not reach the dimensions which are common for this species. When additional dissections were carried out on four-year-old anchovy from the Sevastopol region, twocr three sexually mature specimens of this species were found on two occasions. 32/408-40 9

Aphanurus stossichi (Monticelli, 1891) Loos, 1907

Host: Black Sea anchovy Localization: intestines /409 . The A.stossichi which we discovered were, in their dimensions, very similar to those from anchovy described by Loos in 1907. •

A.V. Reshetillikova notes that this species is found only in winter but attacks anchovy of all ages. We cannot corroborate-- - The Crimean anchovy was infested with A.stossichi in win7 this. ter (5.3%, with an intensity of 8 specimens per fisheenan in autumn (22.2% with an intensity of 12 specimens per fish). This parasite has been noted only once in winter off the Caucasus coast.

Family: Lecithasteridae Skrjabin et Gushchanka, 1954 Lecithaster tauricus Pigulewsky, 1938 Host: Black Sea anchovy Localization: intestines

Trematodes found at the end of May were represented both by ydung maritae whose reproductive system had just begun to develop and by sexually mature maritae with a uterus packed with eggs. The young specimens were 0.766 mm long and 0.280 mm wide. Sexually mature trematodes attained a length of 1.095 to 1.125 mm and a width of 0.375 to 0.420 mm. The mouth sucker was 0.109 to 0.124 mm in diameter, while the ventral sucker had a diameter of 0.233 to 0.254 inm. The pharynx was round, measuring 0.062 to 3.074 mm. The uterus was tightly'packed with eggs measuring 0.018 by 0.010 mm, The lobes of the ovary and the yolk sac measured 0.062

....33 33/409

- to 0.065 mm, and the testes 0.087•mm, i.e. considerably less than indicated by S.V. pigulevskij (1938b).

Family: Lecithochiridae Skrjabin et Gushchankaja, 1954

Svnaptobothrium caudiporum (Rudolphi, 1819) Linstow, 1904

Host: Black Sea scad ("large") Localization: stomach

The length of the body averaged 1.429 mm (from 1.335 to

1.665 mm) with a width of 0.431 mm (from 0.375 to 0.510 mm). The ventral sucker was situated in the first third of the body. It was twice as big as the mouth sucker. Thus, the size of the mouth sucker averaged 0.134 by 0.106 (fin 0.112 by 0.090 to 0.149 by 0.112 mm), while the ventral sucker (which was more round) was 0.291 by 0.233 mm (from 0.270 by 0.267 to 0.330 by 0.270 mm). The pharynx measured 0.067 by 0.057 mm (from 0.050 by 0.037 to 0.074 by 0.071 mm). The testes were flat and o. val, measuring 0.154 by

0.104 mm (from 0 .099 by 0.084 to 0.174 by 0.121 mm). The ovary was round, measuring 0.164 by 0.108 mm (from 0.127 by 0.084 to 0.202 by 0.130 mm), and situated under the testes. The digitate yolk sac lay immediately beneath the ovary. There were two yolk sacs, measuring 0.159 by 0.83 and 0.180 by 0.078 (from 0.124 by 0.059 to 0.236 by 0.056 mm).

Eggs measuring 0.026 by 0.010 (from 0.025 by 0.009 to 0.028 by 0.010 mm) were tightly packed into the uterus. The dimensions attained by S. caudiporum on the scad were small but nonetheless known for the species. The eggs were also rather small. The form which was studied differed somewhat in the contour of the yolk sac (not, however, in all specimens) and in the annulation of the cuticle from that previously described..

...34 34/410

Family: Diniuridae Skryabin et Gushchanskaja, 1954 Ectenurus leDidus Loos, 1907

Host: scad ("large") Localization: Stomach

This species was noted for the first time on the "large"- scad. One or two specimens were noted on two occasions on fish in the spring.

The length of its body averaged 2 mm (from 1.680 to 2.280 mm) with a width of 0.325 mm (from 0.315 to 0.335 mm). The dorsal lip over the mouth sucker was well developed, but the fillet of "granular cells" was not clearly marked. The size of the mouth

sucker averaged 0.097 by 0.092 mm (from 0.081 by 0.074 to 0.112 [

by 0.109 mm); the ventral sucker averaged 0.326 by 0.199 mm (from t 0.279 by 0.177 to 0.370 by 0.220 mm). The testes on the average measured 0.204 by 0.098 mm (from 0.078 by 0.074 to 0.315 by 0.130 mm).. The ovary measured 0.146 by 0.129 mm (from 0.136 by 0.130 to 0.155 by 0.127 mm). Sometimes the branches of the intestines reached the end of the tail appendage; more frequently they termi- nated at a distance from it which was equal to one-tenth of the oVerall body length. The yolk sacs as already noted by P.V. Vlasenko, were fatter and heavier than in the form described by Looss. The remaining indicators corresponded to the initial description.

The Gggs measured, on the average, 0.021 by 0.011 mm (from 0.016 to 0.025 mm long and from 0.010 to 0.012 mm wide).

...35 Lecithocladium excisum (Rudolphi, 1819) Lahe, 1901 Host: Black Sea scad ("small") Localization: intestines

The helminths disclosed on sprat were represented by large forms (2.900 to 3.300 mm long) with drawn-in tail appendages. The entire body of the parasite ftom the ventral sucker to the tail was occupied by a well developed uterus tightly packed with 1 large, well-formed eggs. The position of the ovary and the yolk sac was difficult to diacern among the meshes of the uterus. The remaining organs were not at all visible. The eggs were somewhat iarger than indicated for this species; their dimensions were as - follows;:their length averaged 0.03 7 mm (from 0.034 tit) 0.040 mm), 0.017 mm (from 0.012 to 0.025 mm). and their width,

All the remaining indicators fully coincided with those known for the species. Thus, the width of the body varied from

0.360 to 0.435 mm. The . mouth sucker was large, measuring from 0.248 by 0.186 to 0.304 by 0.223 mm; the ventral sucker, however, was similar to the mouth sucker and more rounded, measuring from

0.171 to 0.192 by 0.171 mm. The pharynx (measuring from 0.158 by

0.149 to 0.174 by 0.139 mm), occupied the entire space between the Suckers; its edges went beyond the sucker. The annulation..of the cuticle was very• clearly marked, while its "curliness" around the "occiput" of the helminth was less noticeable.

Family: Fellodistomatidae Nicoll, 1913 Bacciger bacciger (Rudolphi, 1819) Nicoll, 1914

Host: Black Sea anchovy Localization: intestines

...36 36/410-411

The largest quantities of this parasite were noted in the autumn on anchovy caught off the Crimean coast.

The entire body of the parasite was filled with a well- developed uterus. Tnis proved that we had fully mature trema- /411 •todes under examination, but their sizes were almost one-third those indicated by V.P. Koval' (according to Skryabin, 1957) fOr Bacciger bacciger from th è Black Sea anchovy (see table 13).

Pentagramma symmetricum Tschulkova, 1939 Host: Black Sea anchovy Localization: pYloric -appendages -

• The P.Symmetricum disclosed on anchovy correqponded fully in its morphology to the description and illustration of trematodes which V.N. Chulkova found on herring. The trematodes on anchovy, however, were much smaller (see tâ'ble 14), but at the same timerctaiœdtbe topography and the size ratios of individual parts and organs.

We have noted Pentagramma symmetricum preMbusly on the - Azov anchovy (Nikolaeva, 1961). Trematodes of this species, together with Bacciger baccigere are found in the intestines of Black Sea_anchovy. Both parasites are very similar in several morphological features; if no detailed measurements were taken, an error in determining the species could very easily be made. These species are distinguished by the following features: P. symmetricum is larger than B. bacciger; the length of P. symmetricum is less than three times its body Width, while the length of B.bacciger is slightly less than tWi.ce its body width; the'ventral • sucker on P. symmetricum is 1.5 to 1.8 t±mes.larger than its mouth sucker,

...37 37/411-412 413 while on B. bacciger they are almost equal; the yolk sacs on P.symmetricum are compact and begin beneath the ventral sucker, /4 12 while on B. bacciger they are represented by large follicles

and are situated slightly above the ventral sucker; P.syarnetri- cum's ovary is trilobate and lies below the testes, while on B. bacciger it is oval shaped and lies on the same level as the testes. /413 Since this species was widely distributed on Black Sea anchovy and was not noted by other authors studying the anchovy's parasites, it seems to us that, since these authors made no detailed measurements of all the helminth specimens that they found, they took P.symmetricum in many cases for Baccigevbacciger. It is otherwise difficult to explain why no previous indication was given concerning P.symmàricum's parasitic action on anchovy. This parasite is found on anchovy more frequently than any other species of trematode; it has furthermore been noted in all areas of the sea at various seasons of the year.

Ancylocoelium- typicum Nicoll, 1912 Host: Black Sea scad ("small" and "large") Localization: intestines, pyloric appendages, less frequently stomach

The helminths found on the "small" scad corresponded fully to those described by P.V. Vlasenko and T.P. Pogorel'tseva. The body sizes varied from 0.975 to 1.185 mm with a body width. between 0.192 and 0.330 mm. The cuticle was covered with spines. The suckers were weak; the mouth sucker measured from 0.072 by 0.060 to 0.084 by 0.050 mm, while the ventral sucker measured from 0.0.';9 by 0.069 to 0.099 by 0;087 mm. The prepharynx measured from 0.016

00 038 38/413

to 0.056 mm; the pharynx was round and elongated, measuring 0.037 by 0.040 to 0.065 mm. The gullet was long, measuring from 0.112 to 0.131 mm. Since the dimensions of the helminths which are being described corresponded to those of young forms, it will be understood that their intestinal tubes still did not have the characteristic curvature which is typical of mature maritae of this species. Even on the young forms, however, the uterus was well developed and tightly packed with eggs. The sizes of the eggs averaged 0.024 by 0.011 mm (0.022 to 0.027 bY - 0.009 to 0.016 mm).

It is interesting to note that young forms of a trematode of this species were noted twice on "large" scad in August; one of the forms was still sexually immature, while the other had already begun to produce eggs. The sizes of their bodies varied -from 0.540 to 7O5 mm, with body widths from 0.115 to 0.150 mm. All . the characteristic features of the species were clearly evident.

Iimisiib_r;11.!,1LItn, 1911 Host: Black Sea scad ("small") Localization: intestines

'This species of fellodistomatid was disclosed on "small" scad in autumn. All 22 specimens were young forms of helminths which had already begun to produce eggs; their uteri, however, were poorly developed, and the eggs were small and not fully formed. Odhner (in 1911, according to'Skryabin) noted that heIninths of this species, 1 mm in length, were contained in eggs in the uterus. The parasites which we discovered were 1.110 mm long and 0.186 mm wide. The mouth sucker measured 0.062 by 0.062 mm 'and the ventral sucker, 0.078 by 0.078 mm. The ventral sucker was situated at a distance

...31 39/414-415

of 0.480 mm from the forward end of the body or at the beginning of the second third of the body. The growth of trematodes appeared to us to have taken place mainly through elongation of the rear part of the body, caused by the growth of the uterus. During growth, the position of the ventra1Aucker in the body was altered,

al-though it remained at the same.distance (0.400 to 0.650 mm) from the forward end.

1 -/414- . . The structure of the end portion of the excretory system . was very , clearly visible on young forms. The excretory canal discharged into the excretory bladder. The uroproct had the form

of an obliquely cut wine glass on a long stem....._

Tergestia laticollis (Rud., 1819) Stossich, 1899 i-iost Black Sea scad ("small" and "large") Localization: stomach ,

• On the "small" scad, this parasite attained sizes known for this species in the Black Sea; on a "large" scad was found

a young, sexually immature form 0.885 mm long, with a body width

of 0.217 mm. The mouth sucker measured 0.118 by 0.084 mm, and

the ventral, 0.149 by 0.102 mm.

Family: Lepocreadiidae Nicoll, 1935

Lepocreadium retrusum Linton, 1940

Host: scad ("small" and "large"), Black Sea anchovy Localization: pyloric appendages,less frequently intestines

This species was found for the first time by P.V.Vlasenko under the name of Lepocreadium sp. The scad parasite PhaevnFora polini, described by S.U. Osmanov is unquestionably Lepocreadium

...40 40/414 retrusum (we must here agree with Pogorertseva, who was the first to point out Osmanov's mistake). This trematode was subsequently noted by almost all scientific writers studying the parasites of the "small" scad in various regions of the Black Sea.

A.V. Reshetnikova e in 1954à noted the trematode p.Opechona on ydung scad in the Karadag and Batumi regions; no description of this form, howeiier, -WaS7 publiShed. The genera leocreadium and Opechona are. very similar and are distinguished only by -their ratios of body length to width and by the .length of their prepharynxes. Thus, according to the definition of K.I.Skryabin and V.P.Koval' (1960), the body length of representatives of the tenus Lepocreadium exceeds their body width by 2 to 3 times, while the corresponding „figure for-the genus Opechona is 6 to 7 times. For Lepocreadium retrusum, according to Linton (from the species descriptions of Skryabin and Kovall), this ratio runs from 3 to 4; A.S.Chernyshenko gives it as 4, and T.P.Pogorertseva as 5 to 6. In our material, body lengths were, on the average, four times body widths (from 3.5 to 5 times). This ratio, then, was much greater than that which had been assigned for determining the genus.

Another featùre distinguishing these genera is also highly relative. Thus, on. Lepocreadium the prepharynx is short. Accor- ding to Linton, it is 0.17 ram; A.S.Chernyshenko gives it as 0.08 • to 0.12 mm and T.P.Pogorelltseva as 0.02 to 0.04 ram. On the trematodes whicif we studied, the average length equalled 0.127=1 (from 0.35 to 0.20 mm). On many examples of the genus Opechona, for example, 0.0rienta1is (Layman, 1930), the length of the prepharynx varied from 0.163 to 0.245mm. It is obvious, then, that it is not very clear what is meant by a "long" or a "short" prepharynx.

...41 41/414 -415

The chief die.dnguishing characteristic of the two similar forms L.retrusum and L.pyriforme is the lobed ovary of the former.

Investigators who have studied trematodes from the intestines of

the Black Sea scad disagree on this. V.N.Chulkova, for example, describes an entire ovary, while A.S.Chernyshenko, T.P.Poi;orertseva /415 and A.V.Reshetnikova state that the ovary is lobed. In studying several hundred specimens, we observed both entire and lobed oVaries. Most frequently, the ovary was slightly lObeâ; in such instances it. was triangular in shape.

The yolk sacs on the forms that we studied usually extended beyond the forward edge of the ventral sucker; hence these species

did not differ . essenally as far as this characteristic was concer- ned. The forms which we disclosed confirmed T.P.Pogorertsevais

observations that trematode bodies are capable of considerable con-

traction, ,and are very lively, and that therefore in the study of

total preparations varying in appearance frOm nearly round to narrow and elongated, the impression is occasionally created that they belong to different species.

The forms which we studied were on.the average 1.240 mm.

long (from 0.750 to 1,665 ram). and 0.311 Mm Wide (from 0.193 to 0.375 mm). The mouth sucker usually measured 0.082 by 0.066 mm (0.063 to

0.116 by 0.059 to 0.062 mm) and the ventral, 0.091 by 0.079 mm (0.081

to 0.105 by 0.081 to 0.090 mm). The prickles of the cuticle were very clearly visible. The pharynx was elongated, measuring on the

average 0.067 to 0.047 mm (from 0.050 by 0.047 to 0.094 by 0.035 mm); the gullet measured 0.069 mm (from 0.044 to 0.093 mm). The testes were situated one behind the other; the first measuredon the average,

by 0.100 mm and the second, 0.146 to 0.133 mm. The ovary was 0.125

...42 42/414

smaller than the testes, measuring 0.097 by 0.80 mm. An average of 22 eggs was found in the uterus (from 9 to 35 in each specimen), measuring 0.057 by 0.030 mm (0.050 to 0.062 by 0.025 to 0.034 mm).

One specimen of L.retrusum was found in the intestines of the anchovy. Its body was 0.975 mm long and 0.239 mm wide. _ _ The mputh sucker measured 0050 by 0.040 mm and -the vehtral su- . The teStes measured 0.078 by 0.084 mm cker, 0.062 by 0.059 mm. and 0.084 by 0.074 mm; the ovary measured 0.059 by 0.031 mm and the eggs, 0.062 by 0.025mm. This form was much smaller than that observed on scad. A lengthened oval body with rounded edges was characteristic or it; the cuticle was oovered with prickles; the ihtestinal branches extended to the end of the body; the bursa copulatrix was large and clearly visible around the ventral sucker. The yolk sacs extended above the bifurcation in the intestine; the uteràs was small and extended from the ovary to the ventral sucker; it was filled with a small qUantity of large eggs. The parasitic action of this species on anchovy should be considered as a chance adaptatibn. The "accidental" adaptation of this species was also noted on pickerel (Kostina, 1961).

Class: Mbnogenoidea (Beneden) Bychowsky, 1937 Family: Mazocraeidae Price, 1936 . . Pseudoanthocotvle sp. Host: Black Sea anchovy Localization: gills The representatives . of this family are common for herrihg and mackerel (Bykhovskij, 1957). The genus Pseudoanthocotvle was delineated in detail by B.E. Bykhov.skij and L.F. - Nagibina in 1954 when they described the species P.Pavlovskyi from il . ckerel in the • 1

43/415-416

sea Of Japan. We were able to obtain only one specimen of a monogenetic trematode, and this in a poor state of preservation, we shall therefore describe it only briefly. • The helminth was in thé shape of .a lengthened oval with somewhat constricted forward and rear body ends. The,body . was • 2.010 mm long and 0.390 mm wide. In its fastening disc were four pairs of valves and two pairs - of- hOOkS; -'The valves'oe- the - forWard - /416 pair were large, measuring 0.093 by 0.102 and 0.071 by 0.102 mm, Thé valves of the remaining three pairs were small, measuring only 0.053 by 0.043 and 0.059 by 0.040 mm. We were unable to disclose a:third-pair of hooks. The first pair of hooks measured 0.022mm, and the second, 0.012 mm. The suckers measured 0.025 by 0.034 Mm. -The intestinal tubes were well developed and approached the faSte- ning disc.(see fig. 4). The structure of the reproductive system was the same, as that of the other representatives of the family.

Class: Cestoidea Family: Onchobothriidae Braun, 1900 scolex pleuronectis Muller, 1788

Host: Black Sea scad ("small" and "large") Localization: stomach and intestines

Under the species name Scolex pleuronectis are incorporated the larvae of several species of tape wOrms of the order TetraDhyl- lidae. This is obvious even from the small numbers of such parasites obtained from scad. It should be remembered that they have been noted on mbre than 20 species of fish in the Black Sea. _*.P. Markevich in 1951 observed that It is extremely difficult or even impossible to distinguish these larvae morphologicaliy."

...44 44/416

Some 8. pleuronectis from scad corresponded in shape to the description given by P.V.Vlasenko, i.e. they had appendages lying drosswise with two suckers on them and one central sucker. Thes'a were in the majority.

Others, as described by A.P. Markevich, had two bothridia with suckers and one parietal suCker. Still others corresponded to illustrations shown by Wardle and McLeod in 195 2 for this form. Finally, the fourth group had a head somewhat elongated in with a poorly developed parietal sucker and four large lateral suckùrs.

The larvae were small, averaging 0.507 mm in length (from 0 . 28 5 to 0.840 mm); the maximum'width of the head averaged 0.188 mm (rrom 0.099 to 0.300 mm). The head became constricted towards the . neck, where its maximum width averaged 0.185 mm (from 0.062 t° 0 .300 mm).

The sizes of the appendages or bothridia ranged from 0.078 to 0.0155 mm, and averaged 0.117 mm. The central sucker measured

0 • 074 by•C.056 mm. There were from 4 to 12 lateral suckers, of which the smaller meàsured,on the average„0.036 mm (from 0.034 to 0.037 mm) and the larger, 0.078 mm (from 0.047 to 0140 mm).

Family: Tantaculariidae Poche, 1926 Tentaculariidae gen. sp. larvae Tetrarhynchobothrium sp. larvae Host; Black Sea scad Localization: intestine and gall bladder

Tentaculariidae gen. sp. larvae were found much less freqUently than scolex pleuronectis larvae and were always enclosed

...45 45/416-417

in cysts. In the intestines of "large" scad, cysts became as large as 0.495 by*0.420 mm. Within the cyst four proboscises were visible, of which three extended along the entire body, while one was folded into the head end. Each proboscis had /417 three rows of large claws, measuring from 0.027 to 0.031 mm,

. the base of each claw measured from 0.09 to 0.013 mm.

Cysts were found in both the intestines and the gall

bladder of "small" scad. In the gall bladder, the cysts rea-

ched sizes ranging from 0.720 by 0.495 mm to 0.870 by 0.720 mm. In spite of its larger size, the larva within a cyst was less fully formed, so that only the rudiments of the four proboscises were established. The bodies of all the cysts were entirely occupied by calcareous corpuscles.

Class: Nematoda

Family: Anisakidae Skrjabin et Karokhih, 1945

Contracaecum (Erschovicaecum) aduncum (Rud., 1802) Baylis,

1920 larvae

Host: Black Sea anchovy, sprat and scad ("small" and "large") Localization: Body cavity

When nematode larvae parasitic on anchovy were studied, it was noted that all of them were, with rare exceptions, in one stage of development. The morphological characteristics of various stages of development of Ceduncum from the Baltic flounder were studied by Janiszewska in 1937. The characteristic features of the third stage, as she defined them, are the ratio of overall body length to the length of the gullet, the length of the tail,

and the average thickness of the body. Thus, according to Janisze-

wska, the ratio of the length tô the average thickness of the body

... 416 46-417

is 57 : 40, the ratio of body length to gullet length is 11 : 8,and the ratio of body length to tail length is 73 : 17. At the end of the tail there is a long, well developed prickle.

On contracaecum aduncum from the Black Sea anchovy these ratios were as follows: overall body length to body thickness was 55 : 35; the ratio of overall length to gullet length was 9 : 7, and to the lepgth of the tail, 75 : 34. The average size of the body was 7mm, (from 5.4 to 8.6 mm) (see table 15).

C.aduncum in the third development stage on Black Sea anchovy did not attain the large dimensions noted by Janiszewska for flounder'(up to 20 mm); therefore the ratios of morphological features which we discovered were low. The terminal cuticle prickle was always clearly visible. The ornament on the tip of the tail, characteristic of the fourth stage of development, was still unformed and the lips were rudimentary.

Contracaecum was very rarely parasitic in the intestines of anchovies and no sexually mature specimens were found. Con- tracaecum_larvae were eqUally rarely localized in serous liver membranes, the mesentery, and other organs. Larvae which did , penetrate into these areas usually did not attain even the third stage of development. Most of them were already dead and in va- 1 rious stages of degeneration, whereas in the body cavity all larvae were active.

Contracaecum larvae disclosed on sprat were studied on the basis of the same morphorogical features as thoSe from anchovy (see table 15). The average sizes of larvae on sprat were somewhat larger than those Of ,the larvae on anchovy, measuring 8.4mm (from

...47 I 47/417-418

5.3 to 11.2mm). The ratio of overall body length to body thickness was 52 : 32, to gullet length, 10 : 7 and to tail length, 91 : 43. The value of the coefficients determined was closer to 'those established by Janiszewska for the third stage of Con- tracaecum. Some coefficients (the ratio of body length to tail length) exceeded these limits. C.aduncum larvae on sprat reached the third and fourth stages of development. Most of them were in /418 the larvale state from stage 3 to stage 4. ThiS -Could - be detected particularly clearly along the tail end of the larvae. Under à somewhat drawn-back transparent layer of cuticle with a terminal .pricklee a tail with four rows of prickles, characteristic of the fourth stage, could be clearly discerned. A higher ratio of body length to tail length was observed on larvae in the fourth stage of development.

The Contracaecum larvae disclosed on scad were larger than those on anchovy (their body length ranged from 7.0 to 10.4mm) and were much thicker. The ratio of body length to thickness was 43 35; to gullet length, 9 : 7 and to tail length, 96 : 41. The value of these coefficients was higher than on larvae from sprat. Contracaecum larvae from scad reached a higher stage of development. Most of them were in the fourth stage of development and many were already moulting. Tfie end of the tail usually had four rows of prickles. In summer, the body cavities of scad frequently contained skins from the larvae of Contracaecum in the third stage of development which had completed their moult.

Contracaecum (E.) aduncum (Rudolphii 1802) Baylis, 1920 Host: Black Sea scad ("large" and "small") Localizàtion: intestines •

*6 04 8 48/418-419

Sexually mature forms of this nematode, which is very widely distributed in the Black Sea, were found in scad far less

frequently than larvae. The female nematodes averaged 10.24L in length (from 8.30 to 12.60 mm). The maximum body width averaged /419 0.228 mm (0.220 to 0.273 mm); at the level of the lipse the width

was 0.076 mm; at the ventrical level, the width was 0.176 mm, and at the vulva level, 0.214 mm. The gullet was from 0.975 tô

1.200 mm long and from 0.062 to 0.071 mm wide. The stomach was on the average 0.075 mm long and 0.070 mm wide. The appendix

was 0.521 mm long and 0.050 mm wide, while the stomach appendix

was 0.400 mm long and 0.026 mm wide. The nerve annulus was situated at a distance of 0.210 to 0.330 mm from the forward end. The

distance from the anus to the end of the body was from 0.152 to

0.222 mm. The vulva was 3.840 to 6.200 mm from the end of the body. It was evident from the above sizes that very young females which

had only begun to produce eggs were found &I scad.

The males which were disclosed simultaneously with the

females had already achieved sexual maturity and were from 22.18

to 25.47.mm longe with a maximum body width of 0.345 to 0.420 mm.

The width of the body at the level of the end of the pharynx was 0.12

to 0.140 mm; on the anus level, body width was 0.105 to 0.133 mm.

The distance from the anus to the end of the body was 0.115 to 0.127

mm. The spicules were 1.605 to 2.415 mm long and 0.037 to 0.049 mm wide.

Class: Crustacea

Ea11.1.1x: Ergasilidae Thorell, 1859 Ergasilus nanus V.Beneden Host: Black Sea anchovy Localization: gills

4 • 9 49/419

This. small crustacean is rarely found on anchovy; its intensity of infestation is low.

Ergasilus sieboldi Nordmann Host: Black Sea scad ("small") Localization: gills '

This species was found three times in the gills of "small" scad (one specimen on each scad).

Characteristics of the Parasites- of Local Stocks of Black Sea Forms of Anchovy_t_pprat and Scad.

The composition of the parasites of local fish stocks is closely connected to the biology of the host and the medium which it inhabits. The migratory character of these fish, the composition of their food, their age, the season of the year, and peculiarities in the makeup of the invertabrate fauna dwelling with them, and many other biotic and abiotic factors determine the di-

in versity species of their parasites and the differences in the extent and intensity of their infestation. In analysing the parasites of local stocks of anchovy, sprat and scad, we made every effort to take all these factors into consideration. The parasites of local fish stocks were studied in one, or, at the most, two age groups which are of the greatest commercial importance.

Anchovy. A.A.Majorova and N.I.Chugunova, who in 1954 made a detailed study of local stocks of Black Sea anchovy, noted the existence of two stocks of anchovy, Western and Eastern, each with its own wintering places, spawning and fattening grounds, and migration routes. For the eastern stock, it is characteristic to winter off the coast of Georgia, to spawn in the eastern area of

...50 i.( o

50/41 9 -420

the sea, and to migrate early for spawning and wintering. This /420 anchovy is smaller than the western . anchovy and grows slowly. The western stock winters off the Crimean coast and reproduces and forages in the northwestern and western areas of the sea. Majorova and Chugunova analysed the distribution and migration routes of the anchovy in detail. .While we fully agree with these authors that these two stocks exist, we nonetheless believe that the term "western" is not compleitely accurate when used to describe fish stock dwelling off the Crimean coast. Both its wintering and its spawning grounds indicate that this stock is distributed in northern areas of the Black Sea. Hence it should rather be termed "northern" or "Crimean". Icthyologists have noted that the eggs and larvae of anchovies are distributed in the northwestern region of the Black Sea off the Crimean and Cau- casus coasts and in open water areas near these regions.

The Turkish investigators Einarson and GUrtUk in 1960 indicated some new regions in the Black Sea where the eggs and larvae of the anchovy were distributed. Mass anchovy spawning also takes place in the Bosphorus region. Quoting other Turkish investigators, Einarson and GartUk noted that the anchovy approaches the Turkish coast for wintering and that commercial anchovy fishing is conducted in these regions from December to April. Black Sea anchovy have also been known to move into the sea of Marmora for wintering. Anchovy wintering off the Turkish coast and moving into the sea of Marmora for the same purpose form their own stock, which has isolated wintering, spawning and foraging locations in the Black Sea. This stock should be considered as southwestern or Bosphorus.

...51 • 51/420

1 An analysis of the parasitic infestation of Black Sea anchovy confirms thelr.dirision into local stocks differing sharply in the intensity with which they are infjsted, the number of their parasite species, the characteristics of their trematodes, and their infestation with nematodes and other species of parasite.

An analysis of all the material which we had available on these five features has permitted us to distinguish three stocks of anchovies, as indicated in tables 1 and 16. The in- • tensity of infestation of anchovy, i.e. its infestation with 'all parasite species, varies in different areas of the sea. When anchovy off the Crimean coast are 100% affected by parasites, the

intensity of infestation in autumn amounts to an average of 45 = specimens (from 1 to 220) per fish and in winter increases to 75 specimens (from 2 to 315 per fish). Off the Caucasus coast in winter e .when 95% of the fish are affected by parasites, the intensity of infestation averages 48 specimens (from 2 to 350) per fish. The intensity of infestation of anchovy cffthe southwest shores of the Black Sea in spring is much higher, amounting to 197 specimens (from 22 to 476) per fish.

The reasons for such a difference in infestation may be ascertained only when the parasite species composition has been analysed in each individual region. It should be noted that the various stocks of anchovy differ also as regards the number of parasite species with which they are infested. The largest number of species disclosed on anchovy off the Crimean coast in autumn was 11, 8 species were found on anchovy off the Caucasus coast in winter, and five species in the southwestern region. A coMbination of a small parasite species composition and an extremely high intensity of infestation on anchovy from the southwestern stock demonstrates that a high intensity is cau- l' sed hot, by an abundance of parasite species, but by a high intensity of infestation with one of them.

The discovery of a diverse parasite species composition on anchovy off the Crimean coast may to r a large e)itent be attributed to the fact that fish from this area were dissected in the. course of two seasons and that additional dissections were carried out as well. /422 An interesting relation developed from the infestation of aruchovy - with trematodes in various regions of the Black Sea. In autumn, it was noted that anchovy from the Crimean coast were affli- cted_with 9 species of trematodes, which infested 83.55 of the fish with an average intensity of 33 specimens (from 2 to 210) eachc2_ '. In winter, infestation was slightly higher; this time only 5 trematode species were involved. In the same season off, the Caucasus coast, 5 trematode species with a 60% extent of infestation and an average intensity of 12 specimens (from 1 to 65) per fish were note-CI on anChovy.

The infestation of anchovy in the southwestern region of the Black Sea is of a different nature. Thus, in spring, young anchovy in this area are entirely free from trematodes, while adult anchovy are infested to the extent of only 33.3%j with an extremely low intensity àveraging three specimens (from 1 to 8) per fish. This low rate of infestation with trematodes is not seasonal, since, according to A.V.Reshetnikovats data, in spring off the Crimean coast, 100% of the anchovy are afflicted with Bacciger baccizer,

...53 o

53/422

with an intensity varying from 1 to 78 specimens per fish. Year- ling anchovy at the mouth of the Danube have by this time already with been afflicted Lefc7iir- species of trematodes.

In examining the species composition of trematodes affecting anchovy, it should be noted that such species as Nematobo- . thrium sp. larvae, Lepocreadeum retrusum, and Hemiurus communis ., are not specific for anchovy and are very rarely found on them. No regular pattern can be discerned in infestation with these "casual" parasites.

The extent to which the swim bladders of anchovies are infested with young forms of Lecithochiridae gen. sp. larvae depends upon the age of the fish. Trematodes are found on four- year-old.anchovy more frequently (65%) and in greater quantities (from 1 to 73 specimens per fish), than on-tie) and three-year-old anchovy (11%). This age dependency may exblain the fact that we did not observe this species onLiFchovy from the Caucasus coast, although it had been noted hare previously by N.V.Chulkova, who evidently was investigating a larger fish.

Stephanostomum Pristis larvae, Aphanurus stossichi, Lecithaster tauricus, Bacciger bacciger, and Pentagramma svmme- tricum are found fairly frequently on anchovy; they may be em- ployed to trace peculiarities in the infestation of individual

stocks. •

Pentagram-la symmetricum, Bacciger bacciger and ri.etacercaria of Stephanostomum are the most widely distributed of the tremato2,3s on the Crimean stock of anchovy. In the autumn, 50% of Crimean anchovy are afflicted with Pentagramma symmetricum, with an

! o

54/422-42

intensity of infestation varying from 2 to 12 specimens per fish.

In winter, when this parasite is 83.3% prevalent, the intensity of infestation increases as well, averaging 35 specimens (from 2

• to 91) per fish. In the autumn in this region, bacciger bacciger its is: 55.0% prevalent among anchovy, and/E''— intensity varies

• from 1 to 200 specimens per fish. In winter, however, this hel-

minth is found on only 33.3% of fish, with an-intensity of 6 to

-43 specimens each. In the autumn, S.pristis larvae attack more than half (55.0%) of Crimean anchovy; infestation, however, falls off somewhat during the winter. Aphanurus stossichi is a perma- nent parasite of Crimean anchovy, although in winter infestation

with this species of trematode is slightly reduced.

Caucasus anchovy are afflicted with the same trematode

species as are . Crimean anchovy, but here the intensity of infestation is considerably less. Only larvae of S.pristis, afflicting

30% of anchovy off the Caucasus coast, have been observed to have

a high intensity of infestation. (1 to 64 specimens per fish). The rate at which Caucasus anchovy are infested with P.symmetricum

is one-third that for Crimean anchovy; only 30% of the fish are infested and intensity runs from 1 to 24 specimens per fish. Off /42 the Caucasus coast, 15% of anchovy are afflicted with B.bacciF2er,

with an infestation intensity varying from 1 to 4 specimens per fish, or half that noted for Crimean anchovy.

'hie composition of trematodes on anchovy from the southwestern Black Sea is entirely different. Here, the parasite [lost • frequently found on anchovy is Lecithaster tauri'cus. When it in-

fests 15.4% of the fish, its intensity varies from 1 to 8 speci-

mens. In the southwestern Black Sea, the lower rate of infestatioï

••.55 0 0

55/423

of anchovy with metacercaria of Stenhanostomum pristis results from the fact that here the whiting (this parasite's terminal host) does not feed on anchovy, whereas fish, and primarily arichovy, predominate in the whiting's diet in other areas of the sea, ranging in proportion from 5% (off the Crimean coast) to 28% (off the Caucasus coast). In southern regions, the whiting feeds primarily on crustaceans (Burdak, 1962). Here, the development cycle of S. pristis cannot be completed; hence its low intensity of infestation.

Pentagramma symmetricmn in the form of single specimens attacks 15.4% of southwestern Black Sea anchovy. Here only one specimen of B. bacciger has been observed. This low rate of infestation of southwestern anchovy with the trematodes (P.synmetricum and B. baccier which are most common for, this fish in the Black Sea cannot be explained by either age or seasonal dynamics. All of the anchoy examined were of the same age; furthermore, infestation by B. bacciger, according to A.V. Reshetnikova's data, reaches its peak in spring among Crimean anchovy. Hence the very low infestation of anchovy with these trematode species off the southwestern Black 'Sea coast corresponds to the weak sources of infestation, i.e. the small quant'ity of trematode larval forms. The pattern of infestation of Black Sea anchovy with the trematode P. symmetricum in various areas of the sea is analogous to the way in which it is afflicted with Bacciger bacciger.

The infestation of Black Sea anchovy with Contracaecum aduncum larvae, however, is of a completely different nature. In autumn, anchovy off the Crimean coast were the least afflicted.

...57 • ..■

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At this time, the largest number of uninfested fish and, consequently, the least percentage of infestation for this species - 77.0% - were noted. The intensity of infestation was low, averaging 24 specimens (from 1 to 91). In winter, all •anchovy were afflicted, and the intensity of infestation increased to an average of 37 specimens (from 1 to 223) per fish. The level of infestation of anchovy off the Caucasus coast in winter -was the same; 95% of the fish examined were infested, while the intensity of infestation averaged 39 specimens (from J. to 350) per fish. A very high rate of infestation of anchovy with Contracaeum larvae was observed in spring offthe southqestem shores of the Black Sea. Here, where 100% of the anchovy were afflicted, was.noted the highest intensity of infestation - an average of 197 specimens (from 21 to 476) per fish. This cannot beexplained by the mere seasonal dynamibs of infestation, since A.V. Reshetnikova gives the spring intensity of infestation in the Crimea region as an average of 68 to 70 specimens per fish. A three to four-fold increase in the intensity of infestation indicates that in this region conditions are moi-e favourable for infestation. Anchovy become infested with nemotodes when they feed .on zooplankton. Copepods and Sagitta are the first intermediate hosts for Contracaeum; in the Black Sea, Sagitta is most heavily infested with Contracaeum.

The data which we have obtained does not confirm A.V. Reshetnikovats conclusion of 1954 that from December to April infestation of anchovy with Contracaeum aduncum

...57 57/423-424

is reduced to 46.6%, that the intensity of infestation drops one or two parasites per fish and that the anchovy fattens at this time. The first of these conclusions does not agree with the data from a table on the seasonal infestation of anchovy, supplied by A.V. Reshetnikova herself; according to the data of icthyologists (Majorova, Chugunova, /424 and Minder, 1954), anchovy attain their maximum fatness and condition - from 10 to-15% 7. ip_autumn e -with a decline to_ - 4% in spring:

The infestation of Black Sea anchovy in the spring (off the Caucasus coast and particularly in the southwestern region of the sea) with Contracaeum aduncum larvae becomes epizootic. Fish, particularly those suffering from this epizootic (having 400 or more Contracaeum) lose an average of 2 to 3 gràms, or 10 to 15% of their weight as compared with yearlings which have been less infested. A ball of nematodes in the body cavity sometimes causes partial degeneration of the gonads, hence reducing the fecundity of the fish.

Thus, in.the general pattern of helminth infestation of Black Sea anchovy, trematodes prevail off the Crimean coast. onr the Caucasus coast, there are fewer trematodes, but, in the southwestern region, where infestation with nematodes bpcomes epizootic, they are utterly negligible. A distinctive feature of anchovy off the Caucasus coast is that they are also heavily infested with small parasitic crustaceans.

• 41 58/424

Through the use of parasitological data it may be decided to which stock an anchovy belongs, even in areas where stocks are contigious. For example, anchovy were caught in the middle of May in the Sinop region. This area lies on the boundary between two stocks, the eastern and the southwestern, so that it was difficult to determine to which stock these fish belonged. The absence on the _ anchovy, hoWever, of trematodes and parasitic -cr ustaceans indicated that it belbnged to the southwestern stock. In • another instance, the diverse species composition of parasites (see table 16) on one-year-old anchovy caught in spring at the . mouth of the Danube, clearly indicated that they belonged to the northern stock. At the same time, year-old anchovy from the southwestern stock were infested only with Contracaeum larvae with a low infestation intensity varying from 1 to 10 specimens per fish.

The conclusions which we have reached on the parasites of local stocks of Black Sea anchovy do not contradict data which may be found in parasitological literature. Anchovy have been investigated in various regions of the Black Sea; most of the anchovy which have been studied however, have been caught off the Crimean coast (Lintov, 1901; Pigulevskij, 1938; Isajchikov, 1927; Chernyshenko, 1955; Reshetnikova, 1954; and Butskaya, 1952). The studies of all these authors also indicate that trematodes are widely distributed off the Crimean coast and that here parasite species composition is diverse.

..•59 59/424-426

Several authors (Chulkova, 1939; Kurashvili and Tabidze, 1947, and Pogorelitseva, 1952) have studied anchovy parasites in the Caucasus region. The discovery of the parasitic isopod piE2t122E_Imnçtta on anchovy in this region confirms our conclusion that the presence of parasitic crustaceans is a distinguishing feature of this stock.

A compar±son of the parasites of Black Sea and Azov anchovy (Nikolaeva, 1961) yielded very interesting results.

To avoid the influence of the season on parasite dynamics, we shall-draw comparisonsseparately for spring and autumn (see tables 17 and 18).

. In spring, fOur parasite species, Stephano stonum ib larvae, Baccigecciger, Pentapiramma symmetricum, and Contracaeum larvae, are common to these two forms of anchovy. The Azov anchovy is more heavily infested with trematodes than is the Black Sea anchovy, but is attacked to a far lesser extent by Contracaecum larvae. The intensity of infestation of Azov anchovy with Contracaecum aduncum larvae is only 1/28th of the infestation of the southwestern Black Sea /426 anchovy stock in the same season. A characteristic feature of the Azov anchovy is also the fact that it is infested with

• a small parisitic crustacean, Ergasilus nanus, which has not been observed in the southwestern 'stock of Black Sea anchovy.

...60 60/426

The parasies of these fish are even more diverse in autumn. Thus, eight species of trematodes have a major share in infesting the Crimean stock of Black Sea anchovy. These trematodes affect 83.3% of the anchovy; their average intensity is 33 specimens (from 2 to 210) per fish. The most widespread are Stephan° stomum pristis larvae, • Baccigeigacciger, and Pentagramma symmetricum. Only two species of trematodes are found on Azov anchovy in the autumn; their intensity is very law - far lower, in fact, than in spring. There is also a wide range &A infestation with Contracaecum larvae. This range is More clearly expressed in the intensity of infestation, which, on Azov anchovy, is one-fifth that observed on Black Sea anchovy. In the autumn, Azov anchovy are infested chicfly with small parasitic crustaceans, and principally with Ergasilus nanus, which affects 85% of the fish and has an intensity cd'infestation of 13 specimens (from 1 to 30) per fish. This small crustacean. was found only once on Black Sea anchovy.

This comparison emphasizes once more that the change in the infestation of Azov anchovy, from helminths in the spring to small parasitic crustaceans in the autumn, depends upon the ecological factor, i.e. the anchovy's migration in the sea of Azov in summer. Helminths prevail among Black Sea anchovy which have not migrated at this time.

The fact that the same species of parasite are found on both subspecies of anchovy emphasizes the affinity of the two fish. The crustaceous nature of the infestation of Azov anchovy, however, distinguishes it more from Black

...61 61/426

Sea anchovy than it marks off individual local stocks of Black Sea anchovy among themselves.

Sprat. The change in sprat parasites in various regions of the Black Sea during three seasons of the year is shown in Table 19. In considering the influence of the season on parasite dynamics, it must be noted that only in winter have _Step.:12.2.9„stionlril larvae been noted on sprat, and L, then in only two areas of the sea. During the same period, Infusoria and Halacarae nymphs ‘ were found on sprat; hence sprat parasites differ most in winter. A seasonal change in parasites-was studied on sprat oaught around the mouth of the Danube and here observed in . all three seasons. In wintèr, the intensity of infestation with Nematobothrium larvae was rather high - 34 specimens (from 8 to 116) per fish, although bne fish was found to be free fruliparasites. In spring, in spite of the fact that all sprat were afflicted, the intensity of infestation was far lower, averaging 7 specimens (from 2 to 30) per fish. In summer, the intensity of infestation increased once more, averaging 17 specimens (from 1 to 37) per fish. When all fish were afflicted with parasites, changes in the intensity of infestation of sprat Contracaecum aduncum larvae, depending upon the season of by the year, were of an entirely different nature. Thus, in winter, the intensity of infestation was very low, averaging 6 specimeris; in spring this figure increased to 23, and in summer declined again to 13. A comparison of the dynamics involving of infestation these two species indicates (see figure 5) that they are in complete contrast. A comparison of four regions of the Black Sea (the mouth of the Danube, Karkinit Gulf, the Southern Crimean coast, and the Caucasus coast) in

...62 • 62/426 - 427 winter confirmed the same assumption: the intensity of infestation with Nematobothrium S.P. was greater, while that with Contracaecum aduncum. larvae was less. The more severe infestation of Crimean sprat with Contracaecum was somewhat of an exeption to the rule. The same pattern was evident from average seasonal data.

Only two regions (the Danube and the Turkish /427 coast) were studied in spring. Sprat off the Turkish coast were only slightly infested with Contracaecum aduncum larvae, of which there was an average of 73 specimens (from 14 to 183) per fish. Both these and average data obtained for this time of year confirm conclusions which have been made for Danube sprat.

Sprat. were studied in three regions of the Black Sea in summer. A greater intensity of infestation with Nematobothrium and, particularly, Contracaecum was observed in the - southwestern region. In Karkinit Gulf, on the other handl parasites were very seldom observed. This, however, these does_not alter the general trend of seasonal alterations of infestation. Throughout the Black Sea; the seasonal infestation of sprat changes as indicated for Danube sprat. The infestation of sprat with Nematobothrilm larvae decreases from winter to spring and in summer increases once more. Infestatign with Contracaecum aduncum larvae is low in winter, increases sharply in spring, and falls off somuwhat towards summer. The trend of the seasonal dynamics of infestation of sprat with Contracaecum larvae coincides with that established for anchovy. Sprat is infested with only two parasite species (Nematobothrium and Contracaecum larvae),

.0.63 63/427

Which are distinguished by opposite seasonal dynamics. Their seasonal intenEstyof infestation, therefore, does not alter and remains almost at the same level, 52 parasites in winter, 53 in spring, and 37 in summer.

The infestation of sprat in various regions of the Black Sea indicates the homogeneous species composition of its parasites. Even with all sprat infested, the intensity varies little in different regions of the Black Sea. The intensity of infestation is lowest in Karkinit Gulf, averaging 18 specimens per fish. This is obvious from individual parasite species studied in both seasons (winter and summer), particularly Contracaecum larvae. Infestation of sprat is highest off the southern Crimean coast, averaging 88 specimens, and off the Turkish coast, where the average is 82 specimens per fish. In the former area this results. from an increased infestation with both species of parasite, and in the latter chiefly from a heavy infestation with Contracaecum (73 specimens per fish). In general, a greater infestation of sprat with Nematobothriura.P.larva.e may be

obderved in the Danube, Crimean e. and Caucasus regions (in • the winter), while in the southwestern region, off the southern Crimean coast and, particularly, off the Turkish coast

. (in spring), infestation with Contracaecum aduncum is greater. Our conclusions on the seasonal dynamics of sprat parasites and the extent to which this fish is infested in various areas of the Black Sea cannot be compared with corresponding data by other authors, since such inforhation is extremely meagre. -

...64 64/427-428

The question of local stocks of Black Sea sprat has been completely ignored in icthyological literature. There is only one study, published by A. Stoyanova in 1953, in which the author distinguishes individual stocks of sprat approaching the Bulgarian coast on the basis of the "brain type" method. This method involves fixing the brain of a live fish in a 2% formalin solution. This method cannot be /428 used in parasitological research, since, in complete parasitological dissection, the brain of a live fish is examined by the compressor method, in Which the brain is pressed between glass slides.

The principle conclusions of A. Stoyanova (1953) and'U.G. Aleeva (1958) on the alienation from the coasts of a large mass of Black Sea sprat compelled us to examine the parasites of -this sprat in six different areas of the Black Sea. Even such a fine division as this did not yield any concrete characteristics of the parasites of individual stocks. A study of sprat parasites from a smaller number of areas makes it quite clear that there are no differences whatever in the infestation of this fish.

One of the factors which have led to differences among the parasites of local fish stocks is the adaptation of the latter to offshore water areas (Shuliman, Berenius, and Zakharova, 1959). This is fully confirmed by the example of sprat parasites in the Black Sea. In Karkinit Gulf, the sprat are ckser to the shore and are detached from open sea areas. Only in this area have sprat been observed to be lightly /429 infested. In all other regions, sprat have been cut off from the coasts and distributed over the entire area of the sea.

...65 65/429-1130

This excludes the appearance of differences in sprat parasites in 5imil1ividua1 regions of the sea, and, what is most important) makes it unlikely that local stocks are formed.

Scad. The question of local stocks of Black Sea scad was studied most completely by Y.G. Aleev who, in 1956,1957 and 1959 established the presence of four local stocks; the southwestern (Bosphorus), northern (Crimean), eastern (Caucasus), and southern (Anatolian). The term "southern" includes scad designated in most icthyological dtudies as "large". Studies by Altukhov in 1962 have indicated that the southern scad is distinguished from other stocks by the resistance of its tissues to heat.

The parasites of local stocks of Black Sea scad are illustrated in Table 20. The seasonal dynamics of /430 parasites have been studied using the northern stock as an example. This analysis is indispensable, since otherwise it would be impossible to ascertain whether differences among scad parasites are caused by the season of the year or the location of fish stocks.

In the Sevastopol regim e all scad are afflicted . the year round with parasites. The lowest intensity of infestation has been observed in spring and summer, when the average numbers of parasites noted, per fish, have been 20 and 22 respectively; the highest intensity, 61 parasites per fish, has been noted in autumn; towards winter this has dropped to 52 parasites per fish. The number of parasite species remains at a constant level of 7 to 8 in all seasons of the year.

• II • o 66/43 0 -431-432

Nematobothrium metacercaria are found very seldom and in small numbers; hence this species cannot be considered characteristic of any season of the year. Another larval /431 form of Stephanostomum trematode is found on the small scad in very limited numbers, averaging from 1 to 2 specimens per fish. Infestation is observed in all seasons of the year, increasing in spring and autgmn.

Infestation of scad with Ancylocoelium typicum began at the end of autumn; in the winter we found young helminth forms attacking 3.2% of scad e with an intensity of 2 specimens per fish. A mass infestation, affecting 14.3% of scad, with an intensity of 16 specimens per fish, was observed in spring; the greatest infestation was observed in summer, when 25% of the scad were afflicted with an average of four specimens per fish; all of the parasites were sexually mature. At the beginning of the autumn, the uteri of the worms were packed with eggs and the maritae were dying off.

Almost the same seasonal pattern was observed in /432 the trematode most widely distributed among scad Lepocreadium retrusum. The periods of infestation with this species tended to lag and be somewhàt out of line; hence maximum infestation was observed in autumn, and even in winter continued at a high level. T.P. PogorelItseva noted the same seasonal pattern for these species in 1959. Cestodes were found in very limited numbers; one species was found in spring and summer, and .another, in summer and autumn.

In all seasons of the year, the scad is most heavily attacked by Contracaecum larvae, whicli are found on all scad

•°•67 67/432

specimens. The intensity of infestation with these larvae is also high. In spring an average of 14 specimens is found on each fish; in summer, this figure increases to 19 and in autumn reaches a peak of 43. In winter, it is still high at 37. This infestation with Contracaecum larvae, characteristic of scad, is different for anchovy r and sprat. These differences arise from variations in the feeding patterns of the fish.

According to a study by Aleev in 1957, scad feed on small fish (anchovy, sprat, tiulka, goby and atherinid) and nectonic crustaceans (mycids and shrimp). The scad is, therefore, more frequently a reservoir host for Contracaecum aduncum and infestation with nematodes takes place when it eats infested intermediate hosts, primarily anchovy and sprat. Hence where maximum infestation of intermediate hosts is observed in the spring, this peak is not observed on scad until autumn, and even in winter remains at a high level. In other instances, scad can also be an intermediate host for Contracaecum aduncum when it eats invertebrates.

Parasitic Copepoda have been observed On scad in .autumn, when these *parasites are also found on other fish..

A characteristic feature of scad from thetlorthern (Crimean) stock is that they atie all afflicted with parasites with a high intensity of infestation, averaging 44 (from 2 to 246) per fish. These fish are infested mainly with two helminth species - Contracaecum larvae (affecting all fish, with an average intensity of 32 specimens per fish) and Lepocreadium retrusum (affecting 70% of the fish, with an average intensity of 10 spedimehs). All other specimens are found much less frequently.

• ipegb.—)0 68/432

Stephanostomum larvae affect only 25% of northern stock scad, with low ihtensity. Ancylocoelium typicum affect 10% of the scad with an average intensity of 6 parasites per fish. Other parasite species are found even less frequently.

Only 88 % of scad from the eastern (Caucaâu5) stock are afflicted with parasites, »,rith a much lower average intensity of infestatioa of 10 parasites (from 1 to 65) per fish. This low rate of infestation is partly characteristic of winter, when scad are freefranseveral trematodes. In this same season, however, the northern stock is much more intensely infested. Thus, the eastern stock is only one-third as much infested with Lepocreadium retrusum and Contracaecum larvae. On the other hand, infestation with Stephanostomum larvae is twice as great as in the northern stock.

The infestation of scad in the southwestern stock was much different from that observed in the first two stocks. Infestation herewas not high: with 78.6% of the fish affected, the average intensity of infestation came to 13 parasites (from 1 to 58) per fish, while only 5 parasite species were noted. the A characteristic fe-ature of this stock was/177.asitic action of the trematode Lecitocladium exisum, which has not been noted in othermgions of the Black Sea. Infestation with Steohano- stomum larvae remained at a fairly high level of 42.9%, while the intensity of infestation was low, averaging 4 specimens per /4.33 fish. Infestation with Lepocreadium retrusum was very low, affecting only 35.7% of the fish, with an intensity of two specimens per fish, whereas 92.6% of the northern stock were

...70 . • .

70/433

afflicted in this season, with an intensity of 18 specimens per fish. Only one-third as many scad from the southwestern stock were infested with Contracaecum larvae, while the intensity of infestation was only one-half as much. Sexually mature forms of Contracaecum aduncum, absent in other regions of the Black Sea, were found in the intestines of scad from this stock. Up to 100% of "large" scad, i.e., southern stock scad, were infested with parasites. The intensity of infestation was also very high, averaging 454 parasites per fish. This was 10 times greater than the infestation of "small" scad, scad from the other three stocks. Eleven parasite species were found on the "large" scad. The high intensity of infestation, however, was caused by one species - Stephanostomum -,-:larvae.- These infested the gills and pharynx cavity of the scad profusely (averaging 426 specimens per fish) and were strewn in whitish cysts easily discernible with the naked eyei--- "Large" scad were subject to mass attack by cercaria of this species, hence scad remained for a rather long time in areas by inhabiteelnfested mollusks.

Next in order of extent of infestation are nematode larvae, whicli attack 81.3% of fish, but have a low intensity of-14 specimens (from 1 to 56) per fish. A low intensity of infestation has also been noted for larval forms of cestodes, which average 2 specimens (from 1 to 5) per fish, although they are found on 68.8% of fish.

...71 o

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Hence in spite of their size, "large" scad are most frequently infested by the larval stages of helminths and in this way act as intermediate or reservoir hosts in helminth àevelopment cycles.

."Large" scad àrd far less frequently infested with • sexually mature forms of helminths than with larval forms. Of the latter, the most important is the trematode Syfia,ptobo- thrium caudiporum, which afflicts 43.7% of scad, with an • average intensity of 7 specimens (from 1 to 35) Per fish. This species is characteristic :of "large" scad. Sexually mature stages of Contracaecum aduncum are also found in the intestines of scad. These afflict 37.5% of scad, with an average intensity of 28 specimens (from lto 153) per fish, i.e. they are second in intensity of infestation on scad. I.2222IngslitAn_nn,naull is 18% less frequent on "large" scad than .on "small" scad, and it has a low intensity of infestation of only 1 to 2 specimen's per fish. The infestation of "large" scad Isaith.cther trematode maritae is also insignificant.

>. In October 1958 on the southwestern shores of the Black Sea, we studied a single "large" fàur-year-old scad. In it we discloded 50 Stephanostomum larvae, 1 Syri_e_tEtobothrium caudiporum (a sexually immature form), 1 Lepocreadium retrusum, 1 Scolex pleuronectis, and 200 Contracaecum aduncum larvae. Thus, at the age of four years, a "large" scad had already been infested with the parasite species which are characteristic -of its more mature years.

The helminths disclosed on "large" scad, therefore, .are actually specific parasites for "small" scad. It is

...12 72/433-434

characteristic of the "large" scad that its predatory feeding habits do not alter the makeup of the parasites that infest it. Thus, the "large" scad feeds primarily on anchovy and less on sprat, haddock and surmullet (Tikhonov, Vinnov, Paraketsov and Tkacheva, 1955). Of the helminth larval forms •swallowed by "large" scad together with anchovy and sprat, •only Contracaecum lprvae attain sexual maturity. Sexually mature forms of Contracàecum aduncum are also parasitic on "small" scad.

Scad is not a terminal host for larval forms of trematodes (Stephanostomum and Nematabothrium) and the larvae which enter it die, although it has been noted that some Nematobothria survive for a short time. Hence in spite of its preda:tory feeding habits, the "large" scad has the same linking function in helminth development cycles es the "small" scad.

If the parasites of all four stocks of scad are compared, it will be,seen that the parasites of the "large" scad differ from,those of the "small" scad to a much greater degree than local stocks of "small" scad differ among themselves.

Only one study, by A.V. Reshetnikova in 1954, is available on the parasites of the "large" scad; in it the author notes five species of parasites. These include, first of all, three species of larvae: Stephanostomum, Contracaecum, and Scolex pleuronectis, i.e. the scadIs chief parasites. In addition, one specimen each was found of Helicometra, Pulchella and Ergasilus sieboldi. Consequently, thirteen parasite species are now knoyin for the "large" scad. 73/434

A.V. Reshetnikova referred to the "large" scad as a "Sea of Marmora form" and stated that it had few parasites; this she explained by the fact that this scad had only recently appeared in the Black Sea and that the digenetic trematodes had disappeared from among its parasites. We cannot agree with Reshetnikova's opinion. At the present time, six species of trematode maritae are known for the "large" scad. Less I than 10 years have elapsed since A.V. Reshetnikova studied the parasites of the "large" scad. It is difficult to imagine that so many parasite species could have populated the scad, the choosing it as a definitive host, while trematodes in/maritae stage are usually more narrowly specific. The small number of parasites described by Reshetnikova may be attributed mainly to the limited stildy of the parasites of the "large" scad; the season of the year also has a great deal of influence on research in this field.

Many.authors (Vlàsenko, 1931; Osmanov, 1940; Chernyshenko, 1955; Pogorelitseva,.1952vand Reshetnikova, 1954) have studied the parasites of "small" scad off the Crimean coast. Of 25 parasite species known for scad in the Black Sea, 24 were observed off the Crimean coast. Most of these species are rarely found; their presence depends upon the season of the year, and the frequency with which they are encountered alters from year to year. The number of parasites in the area inhabited by the northern stock varies. For example, in the northeastern region of the Black Sea (in the Kerch district), parasitic crustaceans are more frequently found, while thorny headed worms (Acanthocephalans) prevail in the Karadag region. All ôf the abovementioned factc3 may

.74 74/434-435

have resulted in the absence of several species from the material which we studied. No published information, however, contradicts our conclusions on the characteristic features of the parasites of this stock.

Other authors (Chulkova, 1939; Kurashvili and Tabidze, 1947; Pogorelttseva, 1952v, on the Novorossijsk

region, and Smirnova, 1957) have studied the parasites of the • "small" scad off the Caucasus . coast, the eastern stock. •These studies note nine speciea of parasite.. The absence of certain trematodes from our material may be attributed primarily to the season of the year; in addition, both Helicometra pillçhella and Opechona sp. are very rarely found.

The least study has been devoted to the parasites on

- scad from the southwestern region of the sea. These parasites have been investigated only by N.M. Margaritov, whoe in 1960, noted two species of trematodes and Contracaecum. We, too, have disclosed these species and, in addition, we have noted an intensive infestation of scad of this stock with StePhano- stiphum larvae; hence the list of parasites has lengthened somewhat.

Conclusions

A characteristic of schooled fish is the extreme homogenei;ty of their parasites. Various local stocks of pelagic fish in the Black Sea have a basically identical parasite species composition, and are distinguished primarily by the extent and intensity to which they are infested.

...75 75/435

A study of the composition of the parasit4s of the Black Sea anchovy has indicated the existence of three local stocks formed by this fish in the Black Sea.

A characteristic feature of the parasites of anchovy from the northern or Crimean stock is that they are represented by eleven species which infest 100% of the fish, with an intensity varying from 45 to 75 specimens per fish. When 83.3 to 88.9% of the fish are afflicted, the intensity àf infestation with trematodes attains an average level of 33 to 43 specimens per fish. Pentagramma symmetricum is the most frequently found parasite. In winter, for example, it attacks 83% of anchovy, with an average intensity of 35 specimens per fish. Common parasites are StePhanostonum pristis larvae, Bacciger iger, and Aphanurus àtossichi. Infestation with trematodes is the. most distinctive feature of this stock. The parasites least •ound . on anchovy in this region are nematodes. In the autumn, Contracaecum aduncum larvae attack 77% of anchovy, with an intensity of 24 specimens per fish; in winter, the corresponding figures are 100% and 37 specimens.

Parasites'on anchovy in the eastern or Caucasus sbock are characterised in winter by a lower intensity of infestation/ an average of 48 specimens (from 2 to 350) per amounting to fish, and include 8 species. Trematodes are found less frequently, attacking only 60% of the fish; their intensity of infestation is also lower, averaging 12 specimens (from 1 to 55) per fish. They inclide five species. Of these trematodes, Stephanostomum pristis larvae make up 30%, with an intensity of 15 specimens per fish, while another '30% are composed of

...76, 76/435-436

Pentagramma.s7mmetricum, with an intensity of 8 specimens per fish. Other species are noted even less frequently. Contracaecum aduncum attacks 95% of anchovy with an average intensity of 39 specimens (from 1 to 350) per fish. The small parasitic crustacean Ergasilus nanus is found more frequently, attacking 15% of the fish, with an intensity of 24: specimens (from 1 to 7) per fish. I The parasites of anchovy from the southwestern or Bosphorus stock, including yearlings and adult fish, were studied in the spring. The yearlings were entirely free from trematodes but, on the other hand, 91.5% of them were afflicted with Contracaecum ewith a very low intensity of infestation averaging four specimens (from 1 to 10) per'fish. It may be noted that yearlings from the Crimean stock were,in this seasone already afflicted with four trematode species. The adu. (2+ and 3+) representatives of the southwestern stock were all infested and suffered the greatest level of intensity, with an average of 197 specimens per fish; only 5 parasite species, however, were represented. Trematodes were in the minority, infesting only 33% of the fish, with an intensity level of 3 specimens (from 1 to 8 )per fish. Nematodes were in the majority. Oontracaecum aduncum larvae attacked all of the fish and reached an average intensity level of 196 specimens (from 21 to 476) per fish-, i.e. three to four times higher than in other regions of .the sea. There were no parasitic

crustaceans. /436

Fishermen would be best advised to• catch Black Sea they are . anchovy in autumn, when ,7;-- 31---Iless infested with Contracaecum aduncum,which by mass infestation lowers the quality of the catch.

...77 I 1

77/436

Studies of the parasites of another pelagic fish - the sprat - conducted in six different regions of the sea, have failed to disclose any characteristics distinguishing individual stocks. Sprat in Karkinit Gulf, however, are sharply distinguished by a law level of infestation, amounting to 18 parasites per fish, as against 31 to 88 parasites per fish in the open sea. In the open sea it was noted that sprat were more heavily infesited with NeMatobothrium sp. larvae off the southern Crimean and Caucasus coasts in winter. Off the southern Crimean coast in the southwestern region of the sea, and particularly off the Turkish coast in spring, sprat are more highly infested with Contracaecum larvae.

A considerable mass of Black Sea anchovy are isolated from the coasb,.obviating one of the causes of differences among their parasites in individual regions of the sea.

An analysis of the parasites of Black Sea scad indictes that this fish forms four local stocks. The southern stock, containing "large" scad is more isolated. At the sanie the parasites of "large" scad are represented by the time, same species as are known for the remaining three stocks, i.e. for "small" scad. "Large" scad are most heavily attacked by helminths in their larval stages and primarily by Stephanostomum j more heavily than the "small" which attacks this form 10 times form. The most characteristic of the sexually mature forms is Synaptobothrium caudiporum. Two parasite species predominate on "small" scad from the Crimean stock, attacking all of these fish in all seasons of the year: Contracaecum larvae (always attacking 100% of fish in this group): and Lepocreadium retrusum (attacking from 50 to 92% of the above fish).

641,078 78/436

These two species are found less frequently on scad from the Caucasus stock than on Crimean scad; on the other hand, infestation of these fish with Stephanostomum larvae is increasirig. The trematode Lecithocladium excisum is character- , istic of southwestern scad, which generally have the lowest level of infestation. Stephanostomum larvae are found more frequently on this group of scad than on northern scad, but still have. a low intensity of infestation. The leading parasites on - northern scad àre found two to three times less frequently on scad in the southwestern region of the Black Sea. 79

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Figure 1. Metacercaria of Step_ha- ristis from the gill cavity of an anchovy: a-overall view of Metacercaria; b-equipment of mouth sucker.

Figure 2. Metacercaria of Stephanostomum cesticillum from the gill cavity of a "large" scad: a- equipment of mouth sucker; b- position of metacercaria in cyst.

Figure 3. Lecithochiridae larvae from the swim bladder of an anchovy: a,b, & v- trematodes developed to • an equal degree.

Figure 4. Pseudoanthocotyle SD. from the gills of an anchovy.

Figure 5. Changes in the intensity of infestation of sprat by seasons in the region of the Danube 'River. 92

Translator's Note: The positions of the translated elements of Figure 5 given below correspond to the original diagram:

r.0 Q) 4-1 CI)

cHo

Winter Spring Summer Table 1 _Description of Black Sea Anchovy Examined.

Northern or Crimean Eastern or Southwestern or Bosphorus Caucasus

*1.r:we ca.. nt.enws...... erromra

Sea Region Sevastopol Southern Mouth of Southeastern Anatolian Southwestern area Crimean the Danube area of the sea coast • area of the sea coast

Season Autumn Wint eir Spring Winter Spring Spring

Date of . Oct.1960 Dec.1958 May 1961 Jan.1959 May 1961 May 1961 Research

shinz, Gear Small seine Bottom otter Pelagic trawl Bottom otter Pelagic trawl Pelagic trawl trawl trawl

Number of Fish 18 18 5 20 12

Age (in years) -2-yearolde & 2-year-olds & Yearling 2-year-eds & Yearlings 2-year-olds & 3-year-olds 3-year-olds 3-year-olds &1 3-year-ôlds und er-yearling Table 1 (Cont'd.)

■■ ■ .•■•■weeee....k• •••.Ionneere • own« ow• •••

Northern or Crimean Eastern or Southwestern or Bosphorus Cock Caucasus

Length* in centir metres : Average 10.2 12,3 9.7 11.3 8.1 13.7 Maximum 13.1 15.6 10.1 13.3 8.7 15.4 Minimum 8.8 8.8 9.4 8.9 7.8 11.4

Weight in Grams: Average • 6 .7 10.1 5.8 7.6 3.0 19.1 Maximum 11.7 14.9 8.3 11.3 4.1 25.0 Minimum 3.7 6.9 4.5 2.7 2.9) 10.0

•■•••■

•

* feeel=rs Zeological length. tr%

Description of Sprat Examiped._

Sea Region Southwestern Mouth of the Danube Karkinit Gulf Southn. Caucasus Anatolia Crimean Shore

Sea SOri SUMMer Winter Summer Winter. Spring Summer Winter Winter Winter Spring

Dat of Research. June1960 Dec.1960 Jay1958 Dec.1958 May 1961 'June6l Dec.1958 Dec.1958 Dec.1958 May 1 1961 1 Fis ling gear I Bottom Plankton Bottom Bottom Pelagic Bottom Bottom Bottom - Bottom- Pelagic trawl - net trawl trawl trawl trawl trawl trawl trawl trawl

Nun Der of Fish 15 1 12 7 6) 5 4 14 5

1);:q *(in years) 3+ 2 2+ 2 4 3+ 3 3 3 1%-) Len gth (in AveraD 9.2 8.7 8.8 10.0 9.3 9.1 9.8 9.5 9.4 cen timetres):Max. 10.1 8.2 10.0 9.6 10.9 9.5 9.5 9.5 10.3 11.5 8.3 7.8 8.1 9.4 9. 0 9.0 9.0 8.0 7.7

Wei ght(in Average 4.5 -- 3.9 3.6 5.6 4.9 5.3 5.7 3.6 5.3 . Gra 11s) : Max. 6.5 3.5 5.5 5.0 6.7 5.0 6.6 6.6 7.5 10.0 Min. 2.9 2.8 2.9 5.0 4.8 4.7 4.3 2.9 2.3

_ ■ve-n-n-rg-,*- ,> Age is determined by ratio of bocIY:length to age of sprate after Aleev• (1953) and Aslanova (1954).

Table • 3 Description of Black Sea Scad Examined.

Stock Southern Northern (Crimean) Eastern Southwestern

Region Caucasus region The Sevastopol region of Crimea Southeastern Bulgarian (Batumi) area coast ••••■■••*re• • Winter Autumn Season Summer Spring • Summer Autumn. t Winter

,Date Of Research Aug.1961 Apr.1959 Jul.1959' Oct.- Nov. De.-Jan. Jan.1959 Oct.1960 1958-1959 1958-1959

Fishing Gear Purse seine Small seine Small seine Small seine k Small seine Bottom Bottom bottom trawl bottom trawl otter trawl otter trawl

Number of Fish 17 14 15 27 25 14.

Ae (in years) 9-12 1-2 1-2 1+ - 2+ 1+ - 2+ 11•111

Lengtht in Average 51.1 11.5 11.3 14.7 12.7 11.5 centimetres:Maximum 54.3 13.5 . 14.9 17.5 18 • 1 Minimum 49.0 10;1 10.1 11.6 '9.5 9.

Weight in Average 1100.0 9.5 I.M11 -16.3 20.8 11.9 Grams: • • Maximum 1500.0-- 15.4 22.6 51.5 39.4 Minimum 750.0 6.0 9.1 5.9 6.1

* Zoological length.

,• o 1 97

Table k Parasites of the Black Sea Anchovy Engraulis_encrasieholus_ponticus klex. Parasite Species Localization Number of Percent- Intensity of Fish in- age of Infestation fested Infest/n. Range Average

MyxosporidiOen Kidneys- 1 1. 1 25 sp.

ematobothripm Gills and Pyloric 3 3.4 1 to 2 1 1 Sp. larvae caeca

Stephanostomurn Gill chamber 19 21.6 1 to 64. 7 pristis

Lecithochiridae Swim bladder 2 2.2 1 to 15 8 gen.sp.larvae

Hemurius communis Stomach 1 ••••• •1.1 107

Aphanurus stossi-, Intestines 6.8 1 to 12 chi

Alkecithaster tauri - Intestines and 4 4.5 1 to 8 3 Wks pyloric caeca

•Lepocreadium Intestines 1 1.1 retrusum

Bacciger bacciger Intestines 21 24.0 1 to 200 2 5

Pentagramma Pyloric caeca 34 37.0 2 to 91 18 symmetricnm

Pseudoanthocotyle Gills 1.1 1 sp. Table4LQontld) 98

Parasite species Localization Number Percent- Intensity of of fish age of Infestation --' infested infestin Range Average

Contracaecum Body cavity 82 93.2 1 to 476 59 aduncum •

Stage III Body cavity 2 93.2 1 to 475 54 irvae . 1 • - • Larvae in Liver,intestines 22 26.0 1 to 45 9 other stages and other organs

Ergasilus Gills 4.6 1 to 7 3 hanus -,

TOTALS 86 97.7 1 to 476 . 74 _

Table 5 Parasites on the Sprat

pprattus sprattus phalericus . (RissO)

• asite species Localization Number Percent- Intensity of of fish age of Infestat ion infested infestin Range Average

Stephanostomum Gill chamber 2 2.7 2 to 8 5 Sp. larvae -

Nematobothrium Liver 71 97.2 1 to 116 24. sp. larvae

Contracaecum Body cavity 72 98.6 1 to 183 22 aduncum larvae

TOTALS 73 100.0 2 to 213 46 •

Table 6 Parasites of Black Sea Scad from Southwestern, Northern, and Eastern Stocks.

Parasite Species Localization Number Percentage Intensity of of fish of Infest- Infestation Infested ation Range Average ..---

Nematobothrium Intestines 3 2.3 —

1,p. larvae 1 • •

Stephanostomum Gill chamber 34 26.7 1 to 11 cesticillum

Ancylocoelium Intestines & 9 7.0 1 to 27 6 typicum ,, pyloric caeca

Haplocladus Intestines 1 0.78 - ,22 . typicus

Iecithocladium Intestines -3 2.3 1 to 5 3 excisum

, dleepocreadium Pyloric caeca, 80 62.9 1 to 70 10 ‘101*etrusum intestines - • Tetracotyle sp. Brain 1 0.78 - 1

Scolex pleuro7 Intestines 6 4.7 1 to 3 1 riectis .

Tentaculariidae Intestines 8c, 5 3.9 1 to 2 1 gen.sp.larvae Gall bladder .

Contracaecum Body cavity 114 89.6 1 to 245 27 aduncum & intestines

. . 100

Table 6 (Cont'd).

1 . Parasite Species Localization Number of Percentage Intensity of Fish in- of Infest- Infestation - fested ation 1 Range Average

Contracaecum Stomach 2 1.5 1 to 2 2 • duricum

Trematode Wall of the 4 3.1 50 to 500 90 larvae intestines

Ergasilus Gills 2 1.5 - 1 1 sieboldi

TOTALS . 21 95.3 1 to 253 38 .

Parasites of Black Sea Scad from the Southern Stock learasite *Species Localization Number of Percentage intensity of Fish in- of Infest- infestation fested ation -- Range Average Stephanostomum Gills • 16 1GU.0 159 cesticillum Heart to 710 426

Ancylocoelium Intestines 3 18.7 1 to 5 2 typicum •

Ectenurus Stomach 3 18.7 1 to 2 2 )_epidus

Lepocreadium Pyloric 3 18.7 1 to 2 1 retrusum caeca

‘ . •

101

Table 7 (Contid,)

Parasite Species Localization Number of Percentage Intensity of Fish of Infest- Infestation Infested ation Range Average

Tergestia laticolus Stomach • 1 6.3 ; 2

Trematoda gen. Intestines 25.0 1 to 2 sp. larvae

Synaptobothrium Stomach 43.7 1 to 35 17 caudiporum

•• Scolex pleuro- Intestines 11 68.8 1 to 5 '12 nectis

Tentaculariidae Intestines 6.3 , 2 •ken. sp. làîç-- Contracaecum Intestines, 6 37.5 1 to 153 28 aduncum stomach and - body cavity

Contracaecum Body cavity 13 . 8.1.3 1 to 56 p.4.

.aduncum larvae

TOTALS 16 100.0 169 to 730 1454

I 1

oC\J r-I

Tablé MorpholoR;ical Features of Stephanostomum Cesticillum Larvae from Scad.

■•••••■■

mensions in Northern Stock Southwestern Eastern Stock Southern Stock Average for Scad O Stock of all Stock Millimetres 0 Si)ring Summer--7 Autumn' Autumn Winter oummer Average Average Range Average Range Average- Range Average Range Average Range, Average

Size,of Cyst

\\\ Length of ,757X 0,810x 0,d00-0,8 10x 0,759x 0,675- ,005x 0,800- 0,600-1,05x 0,8341 0,495-0,930x 0,738x 0,495-1,050x 0,783x x0,M2 X0,490-0,000. x0,651 X 0 ,578 X 0,585 x0,495-0,780 «3341 X0,615 - 0,663 X0,585- 0,000 x0,777 x0,490-0,84 Stephanostomum - 1

1,065 •••■•• 0 ,885-1,1 W 0,998 0,885-1,110 .1,020 ! Width of (Dephanostomum 11.■ 0,270 0,3M-0,MQ 0,360 0,270-0,300 . 0,330

0,109x 0,124x 0,109-0,158x 0,131x 0,112-0,130x 0,118x 0,084-0,124 0,104' 0,118-0,18dx 0,147x 0,084-0,186x 0,122x f x0,102 x0,100 x0,105-0,112 x0,114 x0,093-0,124 X 0,106 x0,093-0,109 X 0,108 x0,093-0,124 x0,106 Size of mouth . • sucker 0,143x 0,183x 0,124-0,211x' 0,162x 10,127-0,167x 0,155x 0,102-0,167X 0,129x 0,136-0,186x 0,163x 0,102-0,211x 0,156x x0,102 x0,112 x0,124-0,127 x0,125 x0,127 X 0,135 x0,193-0,130 x0,108 x0,I15-0,155 X 0,141 X0,093-0,155 x0,108 ' . I r 1:1,2-1,4 1:1,3 Size.of 1:1,3 1:1,4 1:1,1-1,3 1:1,1 -1:1,3 . 1:1,3 1:1,2 1:1,2 1:1-1,2 1:1,1 sucker •■•• ••--. 1:1,3 1:1,4 33 I 34 I 34-36 33-35 34 . 35-36 I 36 33-36 34 33:-36 35 Ratio of sucker

Numb'er of spines 0 r-i

Table S (Contrd.)

2›,menSions in Northern Stock Southwestern 'Eastern Stock Southern Stock Average for Scad of all Stock Millimetres Stock Spring Summer Autumn 'Aùtumn Winter Summer Average Average Range Average Range Average Range Average Range Average Range Average

Size of Spine / 1 p. 0,065 1 p. 0,059- 1 p. 1 p. 0,065 0,052 . Ip.0056- 0,047 1 p. 0,050-0,070 0,060x 1 p. 0,050-0,070 0,056 - 0,068 0,061 4.0,050 0,M9 0,058 2 p. 0,028-0,037 X0,034 2 p. 0,028-0,053 ,0 4 1 2 p. 0,050 0,040

0,138X. ,0,071-0,202x 0,131x 6,102-0,118x 0,110x 0,100-0,174x 0,137x 0,118-0,1à0x 0,123k 0,171-0,202x 0,I 28x Size of X0,093 I Pharynx !x0,068-0,105 x0,037 x0,071 -0,112 x0,002 x0,087-0,100 x0,124 .x0,112-0,118 x0,I14 x0,063-0,124 x0,102 ••■■■■•

. •

Localization Pill Gill Muscles of larynx Gill chamber Gill chamber Gill chamber Muscles of gill Icharnler chamber gullet and gills chamber, less frequently of pharynx and gullet. o O

104

Table 9 Experiments in Defining Stephanostomum_from Scad

• 1 Dates of Length No. of Species Progress Results of Experiments of Exp. Metacercaria of Fish of Exp. Dissection in days introduced Infested

1 12-29 June,1959 17 21 Ombre Survived No cysts or worms 110 . .

18 Oct.-11 Nov., 24 13 0 u is 1960 •

-x- ti 24 Nov.-13 Dec., 19 32 u 2 Stephanost. 1961 (another sp.)

24 Nov„,1961-4 Jan. 41 18 n .. u It 1962

; 17 June-18 June, 1 6 Whiting Died Nil ; 1959

eNov.-25 Nov.,1961 1 25 u u u

u 20 June-23 June,1959 3 Stargazer "

• .

sl,!Enm2,211.11.1 from natural infestation. 105

Morphological Featur.es. Lecithochiridae gen. sp. Larvae.

Dimensions in 1 According to According to our data millimetres Chulkova's data • 1 Maximum Minimum Average

Lengthof body 1. 10 1.335 0.645 0. 926

Maximum width 0.33 0.3 30 1 0.180 0. 233 of body

Size of mouth 0.0810.06, - 0. 115X0.102 0. 1020. 0 4 0.113X0.093 sucker • I « I • Size of ventral 0.20 0.248X0.242 ! 0.17410.161 0.19610.191 sucker • iiistance between! 0.16 0.177 I .109 0.158 • lickers 0

Size of pharynx ! 0.062x0.059 I 0.056x0.059 0.05810.056 .

i ■JO : !

'Table 11 Experiments on Determining the Species of Trematodes .from the a:vim Bladder of an Anchovy

'Experiment No. Dates of Experiments Length of No. of Fish Outcome of Results of Dissection , Experiment Trematodes Infested Experiment in days introduced

1 31 Oct.-2 Nov., 1961 2 6 Whitg:hg Died 3 L-ecithochiridae

2 31 Oct.-2 Nov., 1961 2 9 Whiting - Died 2 Lecithochiridae

3 31 Oct. - 20 Nov., 1961 20 26 Slab Surviveè 6 Lecithochiridae

4 31 Oct.- 3 Nuv., 1961 3 26 Whiting Died 1 (?) '

5 1 Nov.- 7 Nov., 1961 6 29 Whiting Died Not dissected

8 Dec. 11 Dec., 1961 3 75 Whiting Died No Lecithochiridae

• 7 9 Dec.- 11 Dec., 1961 2 - 10 Vhiting Died No Lecithochiridae

I 107

Table 12 at.ur_e s . Tremato de s e_r__Lnent_s_

Dimensions (in Exp.No.2, Experiment No.3, lab. millimetres)& Whiting. features. 1 Maximum Minimum liength of body 1 1 .155 1.050 0 .738

Maximum width 0.270 0 .267 0.152

1 Size of mouth 0. 171X0.13 0 0.105X0.0fll 0.074X0.062 0.090X0.079! sucker. 1 Size of ventral 0.251X0.223- 0.298X0.140 0.152X0.102 0.178X0.127 sucker

Distance between 0.217 0.217 0.155 0.186 suckers

; Size of pharynx 0.068X0.056 0.065X0.043 0.040X0.031 0 .05 3X0.037

Character of Clear annul- Annulation clearly marked cuticle ation beyond beyond ventral sucker. the ventral sucker

Position of àex Under mouth orifice sucker . Between suckers

Shape of testis Oval

Testes 1.0.071X0.047 0.115X0.056 0.078X0062 0.097X0.059 II. 0 .0 8 4x0 03 4

Ovary 0 .0.62X0.068 0.102X0.043 0.062X0.043 0.082X0.043

Yolk sac 0.071X0.05 3 0.102X0.078 0.062X0.034 0.082X0.056

Eggs (not fully 0.016X0 .010 Tebryos. formed

1 V..

108

Table 13_ Morphological Features of Bacciger Bacciger from Black Sea Anchovy.

Dimensions According to According to our data (in millimetrBs) Koval, 1957 and features Maximum Minimum Average •

Length of body 0.915 0.405 0. 239 0.319

Maxim ra width 0.533 0.330 0.214 0.259

qize of mouth 0.0945X0 . 0817 0.065X0.053 0.056X0.044 0.060X0.04à sucker

Size of ventral. 0.106X0.120 0.071X0.062 0.059X0.0501 0.066X0.056 sucker •Size of pharynx 0.031X0.028 0.031X04028 0.031x0.028 Size of testes 0.127t00.149 0.084X0.062 0.050X0.040 0.067X0.051 0.149t00.170

Shape of testes Rounded -

Shape of ovary Oval

Size of ovary 0.106X0.170. 0.062X0.037 0.037X0.028 0.050X0.033'

Position of ovary Under ventral sucker.

Shape of yolk sacs Large follicles lying in a compact group 109

Table 13 (Conttd.)

Dimensions According to According to our data (in millimetres) Koval, 1957 and features Maximum Minimum Average \ - •sition of 1 Rear portion of body uterus

Position of Above •'ventr:à1 sucker BURSI CIRI

Position of sex Median orifice

Character of Very light, finely annulated, cuticle formed by small prickles. '

Eggs: Shape Oval, flat on one side Length 0 . 019t00 . 021 0.023 0.020 0.022 Uidth 0.012 0.017 0.012 11› 0.014

Localization More frequently pyloric appendages; less frequently intestines. 110

Table 14_ Morphological Features of Fentagramma

SYmmetricum from Black Sa Anchovy.

1■■•••■

Sizes & Features According to According to our data (in millimetres) Chulkova, 1939

Average Maximum Minimum

Length of body 1.3 to 1.8 0.816 0.960 0.555 .

Maximum width 0.36 to 0.50 0.296 0.31115 0.242

Size of mouth 0.13 to 0.16 0.99X0.087 00115X0.087 0.069X0.078 . sticker

Size of ventral. 0.16 to 0.20 0.148X0.131 0.192X0.142 0.105X0.102 sucker •Length of pharynx 0.06 0:047X0.040 0.050X0.040 0.043X0.040 Length of gullet 0.065 0.108 0.022

Size of testes I 0. 08X0. 04 0.150X0.099 • 0.172X0.122 0.108X0.087

II 0.20X0.16 0.135X0.105 0.155X0.143 0.108X0.062

Shape of testes Oval Oval

Shape of ovary . Irregularly Trilobate ewe ■■•• lob ate

Sizes of ovary 0.16X0.48 toj 0.15X0.16 0.136X0.099 0.167X0.130 0.096X0.071 111

Table 14 (Cont'd.)

Sizes & Features According to According to our data (in millimetres) Chulkova, 1939

Average Maximum Minimum

Size of ovary I 0.066x0.056 0.084X0.056 0.034 lobe II 0.072X0.067 0. 084X0 .072 0.040

III 0.06610.060 0.084X0.075 0.043

Position of ovary In centre Under testes behind testes

Shape of yolk sac Compact Compact with two parts

Sizes of yolk sac 0.08 to 0.18X 0. 1 24X0.069 I 0.15 3.X091 0.071X0.046 II 0. 119X0.à78 0.149X1.005 0.068X0.056

Position of From ventrà1. Rear portion of uterus sucker to rear body; many eggs end

Position of In region of intestinal bifurcation and BURSA CIRI consisting of two parts, of•which the . upper is small and the lower is large.

Length of intes- ••• In large specimens, they extend as far tinal tubes as the rear extremity of the testes and, in small specimens, up to the middle of the ovary.

Position of sex Along middle line of body, above bi- orifice furcation of intestines

Eggs 0.291:0.013 0.026X0.015 0.029X0.017 0.023X0.012 • 112

Table 15 Morphological Features of Contracaecum (E) aduncum Larvae in Black Sea Pelagic Fish.

Sizes (in millimetres) and features Anchovy Sprat Scad

Range lleb;;;i1 body length

Ratio of overall body length to average body thickness

Ratio of overall body length to 'length of gullet

8,4 5,25 11,15 8,5 . 7,0 10,35

Ratio of overall 34,7 45,1 32,0 52,5 . ' 38,0 35,0 43,3 body length to length of tail 8,4 7,0 9,1 8,7 7,1. 10,5 •8,4 7,0 8,9 54,9 33,7 75,5 62,9 43,4 91,2 68,6 41,2 95,7 0,834 0,615 1,080 0,946 0,735 1,155 1,027 0,795 1,230 1 0,134 0,099 0,202 0,140 0,087 0,187 0,129 0,096 0,171 . • ength of gullet 0,177 0,115 0,229 0,186 0,133 .0,239 0,225 0,183 0,273 0,052 0,030 0,07i 0,054 0,040 0,087 0,065 0,053 0,084 0,054 0,031 0,071 0,054 0,047 0,071 0,062 0,050 0,074 0,405 0,315 0,510 0,425 0,375 0,540 0,486 0,375 0,630 Length of tail 0,039 0,025 0,050 0,042 0,034 0,053 0,046 0,040 0,056

0,336 0,285 0,405 0,399 0,300 0,525 0,398 0,330 0,525 .0,024 0,012 0,047 0,025 0,022 0,034 0,031 0,022 0,047 Thickness of body in region of bulb

Stomach: Height Width;

Intestinal appendiX Length/ Width,/

Stomach appendix: Length Width --1

Tabl Parasites of Local Stocks of Black Sea Anchovy.

Name of Organs Northern or Crimean Stock Eastern or Southwestern or Parasite Caucasus Bosphorus Stock Stock Aubumn Winter Spring . Winter Spring 'Spring • • L. 51 bo ntensity Intensity bo Intensity tlo,S Intensity bo (i) Intensity 4- -fi ntensity 4_.) ,P 1r) -P of c•-1 of of • of 0 of (.1.) of 0 0 Q) ep Inf e stn. O Z Infestn. C.) nfeStn. Infe stn. a) Infe stn Infestn . 0 H • 1 c.) F.._{ (1.) cH Rang. Aver. Oc.--1 Fiang Aver . cH Ra.np- Aver . . CD C4.4 Rang Aver. 0 4,, 'Tang:. Aver. w Rang. Aver'. - 0 Ki dneys •V • / Gills

;.• Myxosporidia gen . sp. Liver Nematobothriunt sp. larvae 51ep1ianostomurn pristis larvae Leeitho.eliiridae gen. sp. larvae 5,025-25 25 r\,;iurtts commutes 5,5 1--1 2-2 2 5,0 1-1 ntiriis bladder 55,0, 1.-10 4 1.6,5 1—I 1-1 Lecithaster laurictS 30,0 1-64 15 6,6 5-5 5 11;0 1-15 8 • 'Stomach 1; 1 Lepecreadium retrust\Irn \ • 107-107 I3acciger bacciger‘. 107 22,0 1-12 4 5,5 8-8 8 5,0 1-1 -14t-eg-r-arreffl—e-!:441-tleAtr. nte st 2-2 5,5 2 1 - 1 . • 13,3 . 1-8 4 • Intest 5,5 1-1 1

I-200 36 6-43 - .55 , 0 33.3 25 1 1 6 , 6 - Pyloric 2 1 1 appendage Intest. Intest .

• O • Table'16 (Contid.)

or Name of Organs Northern or Crimean Stock Eastern or Southwestern Parasite Caucasus» Bosphorus Stock Stock Autumn Wie,ter Spring Winter Spring Sp-eing - 4)- No C15 u) 0 g.1 Cl.) b0 (1) Intensity WI .1-) -P In.tenSity b-O-P Intensity 'Intensity bo-P Intensity Intensity cis CO CO cf--f CIJ COCO COU) o f of .P Q) of 4-DO) of 4 -) a) of of 4-DO)-) 0 4-) 4-1 R:1-1 1 Infestn. Infestn. 0 Infestn. `1-4 Infestn. (1) RI 1—■ O 0 1-1 C.) F-I f-1 ■ S- 0 a)cf-I (1) O) CH 1 Rang Aver. Rang.Aver. Rano- Aver. Rang. Aver. Pk 01'Rang Aver. o Rang.Aver. o (It .0 0 (1.1 0 • Pentagramma Pyloric symmetricum. appendage przurs -8370' .2L91 . 35 2.* 4--9. 7 .31 1-24 1-1 Tre.ninloda (1.0-tai)i 83,3 2-210 33 88,9 4-103 43 5 1-117 2660,0 12 33,3 1-8 3 pseudoanthocolyie sp. Gills 5,5 1-1 1 Contracaccum aduncuni 1-91 2.1 100,0 1:228 37 5 13-95 33 95,0 1-350 39 91,5 1-10 100,0 21-476 luG 1-7 Ergasilus nailus 5,5 1-1 1 15,0 _ 3 Body 1--220 48 91,5 i l-10 4 Iod,o 22-476 197 cavity 100,0 100,0 2-315J 75 5 14-31 55 95,0 2-350 1 1 5 . 8 1 ' 5 • Ginn o

Tota

Number . of Paf. species/'

" • • ; * Pound in additional dictions

_ . •

O • •

1 15

Table 17 Parasites on Black Sea and Azov Anchovy in Spring.

Name of Parasite Black Sea Azov

Southwestern Reg.ioni Kerch Strait

Percentage Intensity of Percentage Intensity of of Infest- Infestation of Infest- Infestation ation ation

Range Aver. Range Aver.

• \

Mifraspora caudata . .• . . . .• . 5,5 4-4 Stephanostomum pristis larvae . . . •.• 6,6 5--5 38,0 1--3 Lecithaster tauricus 13,3 1 --8 Bacciger bacciger .6,6 1 --1 22,0 1 --5 3 ** Pentagramma symmetricum • 13,3 1 --1 11,0 1 --8 4 . Contracaecum aduncum larvae '. . . 100,0 21-476 196 94,0 1 --25 7 rnatoto 27,0 3-63 18. Ergasilus nanus ...... . - . 16,0 1 --1

T• •r-7 • . Ido,o 22-7-476 197 94,0 4-64 14 •

5 . - T .

5 î

1 4 • :)■ • o

116

TP-14q_18 __ Parasites on Black Sea and Azov Anchovy in Autumn

Name of Parasite Black Sea Azov

Crimean Shore Nerch Strait

1Percentage Intensity of Percentage Intensity of of Infest- Infestation of Infest- Infestation lationI . ation

Range Aver. Range Aver.

•Nematobothrium sp: larvae . . • 5,5 1 --1 1 Stephanostomum pristis larvae . . . . . : 55,0 1 --10 4 23,0 1-20 Lecithochiridae gen. sp. larvae .•. . . . 11,0 1 --15 8 Aphanurus stossichi . . . ., .. ; 17,0 1 --12 5 Lecithaster tauricus . 5 5 2-2 2 Lepocreadium retrusum . ' 5,5 1 --1 1 • Bacciger bacciger ...... ; 55,0 ' 1 --200 36 4,7 1-1 • 1 Pentagramma symmetricum 50,0 2--12 • Pseudoanthocotyle sp. • - 5,5 --I 1. 1- • Contracaecurn adur larvaLe 77,0: 1 --91. 24 66,0 1 --20 5 • ''. Namat.ode. larvae 57,0 1-120 34 Ergasilus nanus 5,5 1 85,0 1 --30 13 ' Cirmdhla sp 19,0 1 --1 1

:re.941 : .. 1 --200 -45 100, • . 3--146 36 • - t£===== No • of. SPE:4-e.s. 1 1 • 6

f--I H

Table 19 . Parasites_of 13.1aolS ?..egLœns_ei tbe_SQ.e in_V.a.ri,n12s,SPaqQM_Df....tbe Yeart

Name of Season Southwestern Danube -Karkinit Southern Caucasus Turkish Averages for Parasite RegiOn Region Region Crimean coast coast season ceast

Per- [ Inten - Per-. • Inten- Per- Inten- Per- Inten- Per-1 Inten- Per- Inten- Per- Inten- centg., sity of centg. sity o. centg. sitycf centgr sitycf centg sitycf centgl. sity of cnntg.. sity of of 73121. of Jaft . of I Infeen . of Infestn, of Irfeeln, of I Infest-;h of InfeÉ11._ Infestn. Infestn. Infestl Infestn, Infestn. Infestn. -'--- InfebU4 f*R. A. 1A . *RI_A. L *R. A. I *R. A. • R. A__,L_ e‘q= A :Ilumostornuri sp. * 'twee 14,2 87-8 • 8 7,1 2-2 2 6,6 27-8 5 latobottrium sp. • Winter 5 evae 85,7 8-116 34 100 ,0 2-92 24 100 ,0 11-74 45 100,0 1-93 44 90,6 1-116 39 •tracaccum ad. 15 evae 100,0 2 --14 6 100,0 1-4 2 100,0 * .8-66 42 92,3 3735 15 90,6 1 --66 * 15 To-ta1. 20 .100,0 12-118 36 100,0 2-94 26 100,0 20-133 88 '100,0 18 --I30 59 100,0 ' 2-213' 52 aatobothrium sp. arvae 100,0 2-730 7 80,0 2-24 11 90,9 2-730 9 •traceecum ad. Spring uvae • ' 100,0 67-60 23 100,0 147-183 73 100,0 6-183 45

• {--" 1 1 , 1_ • •••.:::1 sp...... »100,0 8-790 30 82 rVZIC • 100,0 30-7207 100,0 8-207 53 I :racaccum ed. Summer 93,3 2-63 22 100,0 1-737 17 100,0 4-5 rvae 4 96,8 1-63 17 100,0 3_95 '7 32 100,0 27-41 13 100,0 3-710 100,0 .2-95 20

Total • 100,0 7-78 100,0 8-14 12 6--158 52 100,0 10 30 100 ,0 6-158 37 1 .phanostomum sp. 4,0 8-8 8 , 7,1 2-2 • 2 larvae Aver . for 93,8 2-63 21 96,0 1 --116 19 100,0 11 --92 13 :natobothrium sp. 100,0 11-774 45 là0,0 1--93 • 44 80,0 2-24. larvne region 11 ntracaecum ed. 1 100,0 3--95 100,0 2-60 13 100,0 1 --10 5 100,0 8-66 42 92,3 3--35 15 100,0 14-183 73 .100,0 67-158 50 100,0 8-118 31 100,01 2-794 IS 20--133 88 100,0 ' 18-130 59 100,0 30--207 82 Total

J . t* Range and Avera "Ct) 4—i

Csble 20 Parasites of Loçal_Ptopk_s_of Black Sea Scad.

■•■•••■■ :tame of 'ara site Organs 1Southern Stock Northern (Crimean) Stock (Original left blank) Eastern Southwestern (Caucasus) Stock Stock o :Summer Spring Summer Alitumn ' Winter Winter Autumn • ).-- • • Intensity Intensity b 0 2 Intensity ,A Intensity b70 Intensity bp ntensity bfle intensity I of of -P iJ3- )...i. of of of of il) jol 4a) 0 c..--1' Infestn. • gnfestn. (1).0 Q) c Infe stn. 0 ce.-1 Infestn. cll n.) nfestn. 0 4-4Tnfestn. 0 4 Infestn. C) 0 H o kr.1 ,i_,) .--. !—'• 1 5-1 e-4 . . 0 a) c, e.) 0) r...., 1 si. t'd Rang. ver. f2Li `8 1Rang Aver. . Rang.verd Rang.jAver. 0 Rang. Aver. ilo be ,Rang .!Ave r . ,iti 1 • 1 L2-- 1 —. - Intest

; Gills /// I LHeart 7,1 6,0 lanosturnum ces- 1 100,0 156-710 426 35,7 1-6 2 18,0 lar.de! 4 ijiuit i_.LIntest. 18,7 1-5 2 14,3 i 16 25,0 nurus 18,7 1-2 2

ocladus typicus ■•■••• ocladium tomach •3 ; Intest

intest i

•■■•■•••e.e. • .-4 n-11

•

Tb].c20 (Cont'd.)

left blank) Eastern . ISouthwe:stern jouthern• Stock Northern (Crimean) Stock (Original Name Of ;Organs (Caucasus ) 'Stock Parasite Stock

;0 Sprinà Summer Autumn Winter Win ter Autumn %ummer ; . •. . • • _ : , g , 4.) Intensity • Intensity • .43 Intensity ; • -P Intensity Intensity 'Int ensity . Intensity .• t ) (r) : ho cc t10 . of (f) of b0 Of b0 of of ., 4-) CI) of 4-D CL) of I 4-) H- ) (1.) 4-) (LP Infestn. Infestn. 4-1 Infestn. Infe stn. Infe stn. • Infestn. (1) 0'.' Lig Infe stn. • iI (1.) 0 g g g a.) PSIA • I-1 !c..) 1---i i > U 1—i I C., H _.)5-, i---- - • - 7" • • -.-. , CO fi-.1 I cH - (11- Rang • Aver . l o Rang Aver . o Rang flyer -1 0 rlang.Aver. . ,e'-i O Rang. Aver . ° nang Aver 4 ■-•'1•- •\--- I• • -•• \ i

urn retru- .-1 Stomach •56,0 sum," -" ;yrlap:01..,m!mium ,' 7 .••■• catliJi pnrum ( ; 1 • ■•• i'renla to !a gen. sp. .1■■ •■•• l arvae— -----. . ■ ■ ■ ■•••• etracotyle • • t) . «M.O. 4,0 •ergestin led •••••• •••••• • ■• •colex .. Dleuronectis\I 18,0 1r7-3 . ■••■•• Brain • --. 1

Stomach

'Intest • ; o C\I r-f

Table 20 (Cont'd.) r Southwestern Name!of Organs ijoutern Stock Northern (Crimean) Stock (Original left blank) Eastern Parasite (Caucasus) Stock Stock

e- • ,Dummer Spring Summer Autumn 'Winter ,Tinter Autumn •• _5 Intensity Intensity • Intensity 'Intensity j • f Intensity 4.y r ntensity . Intensity 4, 4 . bu1 of um I-110 (i) LO of m of of um 1 of of of 14.). Q) (i) CL) 4-) CD +>a- c„,° I nfestn. Infestn. I CH nfestn. Infestn. j Infestn. ; Infestn. 4—t nfestn. rll 0 • (1.) e 1 01-1 jO .1 - ; C.) I• t 1-4 ;-4 1 5.1 e.-1 Rang.Aver. g c'ô P.an.Aver. r4 0 Rang.Aver. po Rang' . Aver R.ang.Aver.:0%) o Rang.T,Aver. ç 4C)i

• • I / 1 G.Blad.S4 in-test. 6,3 ■•••■•• ■••■•■• X Terilactilariidnelen. 18,0 1-2 1 • 7,4 '1-2 sP. Poc • 81;3 1-56 Contracaccum - cavitY 14 '1 00,0 2-50 100,0 5-100 19 100,0 1-200 • 43: 100,0 3-245 37, 88,0 i-60 10 28,6 5-56 aunc. larvae 37,5 1-153 ■•■■•■ 1-2 Controcaectimaduri. ' — 14,3

■■■ I ■11 .1■•• ••■• ■ . _ . •■•■■ atode .1 111, 12,9 50.1100 90

. • _ ■ ••• ••• •■••■■ •••■•■• Lrga.5iius sleboid!,. ••■• 7;4 • 1 4,0 I '100,0 169-730 454 100,0 2—.51 20 1-661 n 78,6 1-58 13 100,0 5-103 22 100 , 0 7-242 100,0 3-246 52 §8,0 1 Gills • .8 7 6 5'•

■■•■■ Total ------

No .pf Par. pe(ies •t