Nematode fauna of small mammals of Karelia

Valentina S. ANIKANOVA*, Sergey V. BUGMYRIN

Institute of Biology KRC RAS, Petrozavodsk, 185610, Russia, *anikanova@krc.karelia.ru

The faunistic complex of the shrew and rodent nematodes of Karelia includes 16 species, belonging to 6 families: Capillariidae (Capillaria incrassata, C. kutori, C. muris-sylvatici, Eucoleus oesophagicala, Hepaticola soricicola), Strongyloididae (Parastrongyloides winchesi), Heligmosomatidae (Heligmosomum mixtum, Heligmosomoides glareoli, Longistriata codrus, L. didas, L. depressa, L. trus), Soboliphymidae (Soboliphyme soricis), Syphaciidae (Syphacia petrusewiczi, S. vandenbrueli), Anisakidae (Porrocaecum depressum). Nematodes of fam. Heligmosomatidae (6 species) and fam. Capillariidae (5) dominated among observed species. Palearctic species accounted for a half (50%) of total species numbers, cosmopolitans - 31%, holarctic species - 19%. Roundworms of shrews were characterized by the highest diversity of species composition (11), life cycles and localization in a host body. The parasites with a simple cycle of development, living in intestine, prevailed (Anikanova et al., 2001). The development of other nematode species is realized with participation of intermediate, reservoir hosts and disseminators. These nematodes are localized in various organs of shrews - oesophagus, stomach, liver, urinary bladder, and have low level of host infection. Five species of nematodes, having a simple cycle of development and living in intestine, parasitize at rodents (Bugmyrin et al., 2001). The various food specializations of shrews and rodents determine species composition of the nematodes and quantitative indices of host invasion level. The highest species diversity of the nematode complex was revealed at dominating host species, Sorex araneus and Clethrionomys glareolus.

Distribution of nematode Cystidicoloides tennuissima in the fish biocoenoses of Paanajärvi - Olanga lake-river system

Juliya BARSKAYA, Olga NOVOKHATSKAYA

Karelian Research Center of RAS, Petrozavodsk, Russia, mihrom@onego.ru

Nematoda Cystidicoloides tennuissima is the typical parasite of Salmonidae fish. Cystidicoloides tennuissima is the parasite of alimentary tract of fish. The parasite fauna of brown trout, white fish and grayling (145 samples) was studied by the common parasitological methods. Analysis of Salmonidae fish parasite fauna showed that the core of the parasite fauna formed in parr 3+. Cystidicoloides tennuissima is the permanent component of the core. The largest abundance index was recorded in parasite fauna of grayling. Cystidicoloides tennuissima is the dominant species in the parasite fauna of this host. It is peculiar that Cystidicoloides tennuissima is registered in the parasite fauna of brown trout or white fish only in the case if waterbodies are inhabited by grayling. The increasing of specific composition of parasite fauna of Salmonidae of older age groups leads to the increasing of number of species in the core. In addition, the species forming the parasite fauna of parr as Cystidicoloides tennuissima remain in the core of parasite fauna of adult specimens. The infection index of grayling by Cystidicoloides tennuissima is still higer. How it was reported when was discussed the fauna of parr, the grayling has the high infection by Cystidicoloides tennuissima. So, the grayling is the main definitive host of Cystidicoloides tennuissima. This host supports the size of population of Cystidicoloides tennuissima.

Nematodes of fishes from freshwater reservoirs of Primorye (Russia)

Alexey V. ERMOLENKO*, Marina B. SHED’KO

Institute of Biology and Soil Sciences FEB RAS, Vladivostok, 690022, Russia, *ermolenko@ibss.dvo.ru

Forty species of parasitic nematodes were found in the fishes from freshwater reservoirs of Primorye 2400 specimens of 70 fish species were studied). Six species of nematodes are of marine origin, 33 species are of freshwater origin and Oswaldocruzia filiformis had got into the fish by accident. Fish are the intermediate hosts for Gnathostoma spinigerum, Dioctophyme renale, Porrocaecum sp., Cotracaecum sp., Anisakis simplex, Pseudoterranova decipiens. For Raphidascaris acus and Hysterothylacium aduncum fish are the intermediate and definitive hosts. For 32 species of the worms fish are the definitive hosts. In the last case Capillaria salvelini and Cucullanus truttae can be developed without the intermediate hosts, and the life cycle of other species passes through intermediate hosts both planktonic invertebrate (Copepoda, Euphausiacea) and benthonic one (Amphipoda, larvae of the amphibiotic Insecta, Oligochaeta). The highest species diversity of nematodes (29 species) was registered in the fish of Khanka Lake basin. 25 species of the worms (2 species of marine origin) were met in the Ussuri River basin, 20 (4) species were met in the rivers of the southern Primorye, 13 (4) species were met in the rivers of the eastern slope of Sikhote-Alin. The nematodes that were found in the fish from the last area are of holarctic origin only (they belong to the boreal foothill complex, boreal flat, pacific foothill and arctic freshwater faunistic complex). On the contrary in the Ussuri River basin and especially in the Khanka Lake basin the representative of the southern species complex (Chinese flat and Indian flat complexes) predominate. In the southern Primorye the number of holarctic species and Chinese-Indian species was approximately equal. Such distribution of the parasites is connected partly with a water body hydrology, but basically - with the historical reasons which have defined an opportunity or impossibility of setting in those or these reservoirs for nematode species of different origin.

Distribution of the swim bladder nematodes of salmonid fishes in the Far East of Russia

Marina B. SHED’KO*, Alexey V. ERMOLENKO

Institute of Biology and Soil Sciences FEB RAS, Vladivostok 690022, Russia, *mshedko@dvo.ru

Up to the present time four species of nematodes of genus Cystidicola and Salvelinema have been recorded from the swim bladder salmonid fish: C. farionis, C. stigmatura, S. salmonicola, S. walkeri.The systematics of these worms has been unusually confusing before their revision. All four species of nematodes are known in watersheds of eastern part of Pacific basin. In the rivers of Japan only S. salmonicola was registered. Cystidicola farionis and Salvelinema salmonicola are undoubtedly marked in various regions of Far East of Russia on the literary and our original data. The samples of 8 genera of salmonid fish were studied in the reservoirs of Primorye, Kamchatka Peninsula, Kurile Islands [Kunashir, Paramushir], South Sakhalin, the Sea of Okhotsk; also the collection of Mamaev and Paruchin (1958) was examined. The area of first of them coincides with distribution of the intermediate host, Pontoporea affinis (Amphipoda, Crustacea), and includes the rivers of Chukchi Peninsula, Kamchatka Peninsula (especially in its eastern part), Amur River basin (main river-bed and northern inflows), the Sea of Okhotsk and probably the water of North Sakhalin. C. farionis was found in various species of genera Salvelinus and Oncorhynchus, in Hypomesus olidus, Parasalmo mykiss, Thymalus mertensi, Osmerus mordax dentex, Coregonus ussuriensis. S. salmonicola is distributed in the southern region of the Kamchatka Peninsula, Kurile Islands, South Sakhalin, in the main river-bed and southern inflows of Amur river (Ussuri river basin) and in Primorye. Gammarus koreanus was registered as the intermediate host of this nematode species. S. salmonicola basically was met in fish of the genera Salvelinus and Oncorhynchus, Brachymystax lenok, Hucho taimen, Thymallus spp., Coregonus spp., and very seldom in Brachymystax tumensis. The peculiarities of infection by nematodes of different hosts are discussed also in the present work.

© Russian Society of Nematologists, Institute of Marine Biology FEB RAS, 2002