UDC 574.5
V N. Dolgin, B. F. Sviridenko
FRESHWATER MOLLUSKS OF THE BASINS OF THE PUR AND THE TAZ RIVERS (WEST SIBERIA)
The history of research is considered and information on current species composition of freshwater molluscs basins Pur and Taz is provides.
Key words: freshwater molluscs, habitat, distribution.
The fauna of freshwater mollusks in West Siberia has been studied for over 150 years. Nevertheless, in this huge territory some areas can be found where malacofauna has not been studied thoroughly because they are difficult to reach. Among such areas there are the basins of the Pur and the Taz rivers in the northeast of West Siberia, the basin of the Pur River covering a significant part of the Taz Peninsula.
The first report on freshwater malacofauna of the Taz Peninsula was a paper by I. M. Khokhutkin (1966) who studied the water bodies of the lower Ob basin and the Yamal and the Taz peninsulas and reported for this vast region 11 species of freshwater mollusks: Parasphaerium rectidens (= Sphaerium rectidens), Cyrenastrum asiaticum (= Sphaerium asi-aticum), Cincinna sibirica (= Valvata sibirica), Lym-naea stagnalis, L. peregra (= Radix pereger), Planor-barius corneus, Planorbis planorbis, Anisus acroni-cus, Sibirenauta elongata, of which for the Taz Peninsula the occurrence of Parasphaerium rectidens, Cyrenastrum asiaticum, Cincinna sibirica, Lymnaea stagnalis, Planorbarius corneus, Planorbis planorbis, Anisus acronicus, Sibirenauta elongata has been confirmed [1].
V. N. Drozdov (1967) for the basins of the rivers Messo-Yakha, Taz, Pur, Nyda and Nadym reported 16 species of freshwater mollusks: Sphaerium corneum, Cyrenastrum scaldianum (= Sphaerium scaldianum), Pisidium amnicum, Conventus conventus (= Pisidium conventus), Cincinna piscinalis (= Valvata piscinalis), С. sibirica (= V. sibirica), Lymnaea stagnalis, L. au-ricularia (= Radix lagotis), L. peregra (= R. pereger), L. truncatula (= Galba truncatula), Physa adversa, Planorbis planorbis, P. carinatus, Anisus spirorbis, A. acronicus (= Gyraulus gredleri). Of these, for the basins of the Taz and the Pur rivers confirmed are Sphaerium corneum, Pisidium amnicum, Conventus conventus, С. sibirica, Lymnaea stagnalis, Physa adversa, Planorbis planorbis, Anisus acronicus [2].
In 1970-1971, an expedition from the Laboratory of Hydrobiology and Fish Farming of the Scientific Research Institute of Biology and Biophysics, Tomsk State University, studied the freshwater malacofauna of the water bodies of the lower basin of the Taz River near the Tazovsky settlement. As a result of the study V. N. Dolgin (1973) added 19 more species of mollusks to the previously known ones [3].
In July/August 2009, as a member of a group from the Laboratory of Hydromorphic Ecosystems of the Scientific Research Institute of Nature Management and Ecology of the North, Surgut State University,
B. F. Sviridenko performed hydrobiological studies in the middle reach of the Taz River (Krasnoselkupski region, the reach between the junctions of the Mangazea and the Khuttiyakha rivers) and the Pur River (near the Urengoy settlement), in the rivers of Yamsovey and Tydeotta [4]. In this area, in addition to the previously reported species, for the first time species of the Colletopterum genus: С. rostratum, C. anatinum were found. The occurrence of species of this genus in West Siberia far beyond the Arctic Circle is quite interesting. In the basin of the middle reach of the Ob River and the lower reach of Irtysh, the species of this genus occur quite often and proliferate. Also, species of this genus have been reported for the basin of lower Yenisei, even for higher latitudes.
Species of the Colletopterum genus could appear in the basin of the Taz River by two ways. The first way is connected with the ancient run-off of the Ancient Ob which reached to the north along the Aganskaya clough across the Sibirskie Ridges and along the Pur system up to the Gulf of Taz. The other way might go along the ancient Yenisei-Taz through valley of the Yenisei-Taz interstream area [5].
Today, a detailed study has been carried out of the collection material of the freshwater mollusks collected in the water bodies of the basin of the lower reach of the Ob River, in the basins of the Nadym, the Pur and the Taz rivers. The species were identified by V. N. Dolgin at the Institute of Zoology, Academy of Sciences of the Russian Federation. The analysis of the geographical distribution of the mollusks on the north of West Siberia suggests that the malacofauna of the water bodies of the basins of the Pur and the Taz rivers is represented by 64 species (see the Table).
The species composition of the mollusks and their proliferation are closely connected with the zonation of the territory, specific adaptation of species to certain biotopes, and regional geophysical specifics of the northern part of West Siberia, in particular, the basins of the Pur and the Taz rivers located in the Subarctic and the Arctic Zones.
In the Subarctic Zone, in river waters within the basins of the Pur and the Taz rivers there are 16 mol-
The species composition and the habitat distribution of freshwater mollusks in the water bodies of the basins of the Pur and the Taz rivers (* species newly reported for the studied region)
Biotope types Biotope types
Species composition S-i e 2 Subordinate Floodplain Upland Species composition r e 2 Subordinate Floodplain Upland
1 2 3 4 5 1 2 3 4 5
Bivalvia Gastropoda
Family Unionidae Family Valvatidae
1. Colletopterum rostratum (Rossmaessler) * + + - - 34. Cincinna klinensis (Milach.) - - + -
2. C. anatinum (L.) * + + - - 35. C. depressa (C. Pf.) - - + -
Family Sphaeriidae 36. C. pulchella (Stud.) - + + -
3. Musculium johanseni Tscher. + + - - 37. C. frigida (West.) - - + +
4. Musculium compressum (Midd.) + + - - 38. C. sibirica (Midd.) - - + +
5. Paramusculium inflatum (Midd.) + + - - 39. C. confusa (West.) + + + -
6. Cyrenastrum transversale (West.) + + - - Family Bithyniidae
7. C. asiaticum (Mart.) + + - - 40. Opisthorchophorus troscheli (Paasch) - - + -
8. C. caperatum (West.) - + + + 41. Boreoelona contortrix (Lindh.) - - + -
9. Sphaerium corneum (L.) - + + - Family Lymnaeidae
10. S. levinodis West. - + + + 42. Lymnaea fragilis (L.) - + + -
11. Parasphaerium rectidens (Star. et Str.) - + + - 43. L. stagnalis (L.) - + + -
Family Pisidiidae 44. L. terebra terebra (West.) - + + -
12. Pisidium amnicum (Muell.) + + - - 45. L. palustris (Muell.) - + + +
Family Euglesidae 46. L. atra zebrella (B. Dyb.) - - + +
13. Lacustrina dilatata (West.) - + + + 47. L. auricularia (L.) - + + -
14. Conventus conventus (Cless.) - - + - 48. L. tumida (Heeld) - + + +
15. C. urinator (Clessin) - - + + 49. L. dolgini Gundr. et Star. - - + +
16. Tetragonocyclas milium (Held) - - + + 50. L. zazurnensis Mozley - - + +
17. T. tetragona (Norm.) - - + + 51. L. igarkae Gundr. et Star. - - + -
18. Henslowiana suecica (Cless. in West.) - + + + 52. L. juribeica Krug. et Star. - - + +
19. H. nordenskjoldi (Cless. in West.) - - + + Family Physidae
20. H. waldeni (Kuiper) - - + + 53. Sibirenauta sibirica (West.) - - + +
21. Pulchelleuglesa pulchella (Jenyns) - + + - 54. S. elongata (Say) - - + +
22. E. ponderosa (Stelfox) - - + + 55. Physa adversa (Costa) - - + +
23. Roseana borealis (Cless. in West.) - - + + Family Bulinidae
24. R. globularis (Cless. in West.) - - + + 56. Planorbarius corneus (L.) - - + -
25. Pseudeupera mucronata (Cless. in West.) - - + + Family Planorbidae
26. P. subtruncata (Malm) - + + + 57. Planorbis planorbis (L.) - - + -
27. Cyclocalyx cor (Star. et Str.) - + + - 58. Anisus johanseni (Mozley) - - + -
28. C. lapponica (Cless. in West.) - + + - 59. A. vortex (L.) - - + -
29. C. scholtzi (Cless.) + + + - 60. A. leucostoma (Millet) - - + -
30. Cyclocalyx johanseni (Dolg. et Korn.) - - + + 61. Anisus dispar (West.) - - + -
31. Cingulipisidium splendens (Baudon) - - + + 62. A. crassus (Da Costa) - - + -
32. C. nitidum (Jenyns) - - + + 63. A. stroemi (West.) - - + -
33. C. feroense Korn. - - + + 64. A. acronicus (Ferussac) - + + +
lusk species: Colletopterum rostratum, C. anatinum, Musculium johanseni, M. compressum, Paramusculi-um inflatum, Cyrenastrum transversale, C. asiaticum, C. caperatum, Pisidium amnicum, Henslowiana sueci-ca, H. nordenskjoldi, Cyclocalyx scholtzi, Cincinna klinensis, C. depressa, C. sibirica, C. confusa, while in the Arctic Zone there are only five 5 species: Cyrenastrum asiaticum, Lacustrina dilatata, Cyclocalyx scholtzi, Cincinna confusa, Anisus acronicus [6].
The proliferation of mollusks in rivers is also weak, although in certain parts of rivers their abundance and biomass may reach significant levels [6]. In the Subarctic Zone, the abundance of the mollusk colonies can reach 520 per m2 (96.6 per cent of the zoobenthos abundance), and their biomass can reach 8.6 g/m2. In
river systems, the average abundance of mollusks is up to 93 per m2 (52.5 per cent of the average zoobenthos abundance), and their biomass amounts to 2.4 g/m2 (66.7 per cent of the zoobenthos biomass).
In the Polar Regions, in sprouts of the Pur and the Taz rivers, as well as in small rivers flowing out of lakes, the abundance of the mollusk colonies can reach 2200 per m2, and their biomass amounts to 69.5 g/m2. In average, in polar river systems the abundance of mollusks amounts to 210 per m2 (41.1 per cent of the zoobenthos abundance), and their biomass 4.3 g/m2 (76.8 per cent of the zoobenthos biomass).
In the subordinate water bodies of polar rivers, the species composition is considerably greater. There, in addition to the species mentioned above, there are
Henslowiana suecica, Pulchelleuglesa pulchella, Cy-clocalyx cor, Cincinna pulchella, Lymnaea fragilis, L. zazurnensis and some other species.
In the subordinate water bodies of the Pur and the Taz rivers in the Arctic Zone, the flow is typically slowed down (in lateral channels) or completely absent (in long river bays, broadlands, embayments). Such water bodies typically build up higher levels of organic silts than river systems and have richer aquatic and near-bank water vegetation. Due to the favorable ecological conditions, freshwater mollusks proliferate and have a rich species composition [3].
In the subordinate water bodies of the river systems in the basins of the Pur and the Taz rivers, there are 28 species of mollusks. The maximum number of species is found in subordinate water bodies of the taiga zone, where, in addition to the river mollusks, the following species are found: Pulchelleuglesa pulchella, Cyclocalyx cor, C. lapponica, C. obtusalis, Cincinna depressa, C. pulchella, C. helicoidea, C. frigida, C. sibirica, Opisthor-chophorus troscheli, Bithynia contortrix, Lymnaea fragi-lis, L. stagnalis, L. terebra terebra, L. palustris, L. au-ricularia, L. zazurnensis, L. obensis, Planorbis planorbis, Anisus johanseni, A. vortex, A. leucostoma.
In the Arctic Zone, in subordinate water bodies in the basins of the Pur and the Taz rivers the species composition of mollusks is significantly depleted. Many Gastropoda species are absent. The following species dominate: Pulchelleuglesa pulchella, Cyclocalyx cor, C. obtusalis, Cincinna pulchella, C. helicoidea, Lymnaea zazurnensis, L. terebra, L. fragilis.
The maximum abundance and biomass of freshwater mollusks in subordinate water bodies of river systems is also observed within the taiga zone. The average abundance of mollusks is б34 per m2, and their average biomass is 13.8 g/m2, which amounts to 78.4 per cent of average abundance and 89 per cent of average biomass of the zoobenthos, respectively.
In the subordinate water bodies of the rivers of the Arctic Zone, the proliferation of mollusks is significantly weaker than in rivers. The greatest abundance of the colonies here is 780 per m2, and biomass 10.7 g/m2. Averagely, in the polar subordinate water bodies the proliferation of mollusks is up to 257 per m2, their biomass being 4.5 g/m2, which corresponds to б0.5 per cent of the average abundance and 84.9 per cent of the average biomass of the zoobenthos.
Floodplain lakes of the basins of the Pur and the Taz rivers are the most favorable biotopes for freshwater mollusks. In these, the greatest number of species occurs. In addition to previously reported species of mollusks from subordinate water bodies that are also found in floodplain lakes, species appear that either prevail in floodplain lakes or occur only there.
In floodplain lakes of the Subarctic Zone, the most abundant are the following species: Cyrenastrum asi-
aticum (Mart.), Conventus conventus (Cless.), C. uri-nator (Cless), Cyclocalyx lapponica (Cless. In West.),
C. feroense Korn., С. nitidum (Jenyns), C. splendens (Baudon), Cincinna klinensis (Milach.), С. depressa (C. Pf.), C. frigida (West.), Boreoelona contortrix (Lindh.), Lymnaea fragilis, L. dolgini Gundr. et Star., Planorbarius corneus (L.), Planorbis planorbis (L.), Anisus johanseni (Mozley), A. vortex (L.), A. leucos-toma (Millet).
To the Arctic Zone up to 68°N the following species spread: Cyrenastrum caperatum, Sphaerium cor-neum, Parasphaerium rectidens, Pisidium amnicum, Tetragonocyclas milium, Henslowiana suecica, Pseu-deupera subtruncata, Cincinna pulchella, C. sibirica, Lymnaea fragilis, L. palustris, L. terebra terebra, L. atra zebrella, L. auricularia, L. igarkae, Physa adversa, Anisus dispar, A. crassus, A. stroemi [7, 8].
Within the Arctic Zone, only in floodplain lakes the following species occur: Sphaerium corneum, S. levi-nodis, Parasphaerium rectidens, Lacustrina dilatata, Conventus conventus, С. urinator, Tetragonocyclas milium, Cincinna pulchella, C. confusa, C. sibirica, Lymnaea fragilis, Sibirenauta sibirica, S. elongata, Physa adversa, Anisus leucostoma, A. dispar, A. cras-sus [б].
The abundance of mollusks in the floodplain lakes of the basins of the Pur and the Taz rivers is somewhat lower than in subordinate water bodies of the river systems. Within the taiga zone, mollusks in floodplain lakes prevail in mass (due to large Gastropoda species), but are significantly lower in quantities than other groups of zoobenthos. The greatest abundance of mollusk colonies is up to 1840 per m2 with biomass reaching 29.8 g/m2. The average number of mollusks in floodplain lakes in the taiga zone is 228 per m2, their biomass being 6.3 g/m2, which is 27.5 per cent of the abundance and 63.6 per cent of the biomass of zo-obenthos, respectively (leaving out many Gastropoda species living on the plants in mid-water and near the surface).
In the tundra forest zone and the tundra zone, the abundance of mollusks in floodplain lakes is somewhat higher than in floodplain water bodies of the taiga zone, but their biomass is significantly lower. This is due to the prevalence of smaller species Bivalvia to the north of the Arctic Circle.
The greatest abundance of mollusks in some lakes of the Arctic Zone reaches 2040 per m2, and their biomass 15.4 g/m2. The average abundance of mollusk colonies in floodplain lakes to the north of the Arctic Circle amounts to 346 per m2, and their biomass 3.4 g/m2, which is 26.5 per cent of the abundance and 37.4 per cent of the biomass of zoobenthos.
Upland lakes significantly differ in ecological conditions from all the other water bodies. Water in upland water bodies (especially in the tundra zone) is
weakly mineralized and very much depleted in organ- ularis, Pseudeupera subtruncata, L. zazurnensis, L.
ics. The bottom is solid and sandy, with only scarce juribeica, Sibirenauta sibirica, S. elongata, Anisus
areas of slight silting. There is almost no aquatic veg- acronicus.
etation, with some near-bank water plants present. The The proliferation of mollusks in upland lakes is al-
malacofauna of upland lakes is a strongly depleted most identical into all the three zones of the northern
version of that of floodplain lakes. Usually, the Bival- part of West Siberia and significantly lower than in
via species prevail. In the upland lakes in the area of other types of water bodies. The abundance of mollusk the basins of the Pur and the Taz rivers, the following colonies here rarely reaches 500 per m2, and their biospecies are the most abundant: Sphaerium levinodis, mass is within 3.4 g/m2. The average abundance of
Parasphaerium rectidens, Lacustrina dilatata, mollusks in upland water bodies is 94 per m2, and bio-
Henslowiana suecica, Tetragonocyclas tetragona, H.mass 1.4 g/m2, which is 37.6 per cent of the abundance nordenskjoldi, H. waldeni, Roseana borealis, R. glob- and 73.7 per cent of the biomass of zoobenthos.
References
1. Khokhutkin I. M. Some data on the malacofauna of the Yamal and the Taz peninsulas // Works of the Institute of Biology. Sverdlovsk, 1966. Vol. 49. P. 65-66 (in Russian).
2. Drozdov V. N. Comments on the fauna of mollusks of the polar Ob area // Issues of Hygiene. Omsk, 1967. P. 42-45 (in Russian).
3. Dolgin V. N., loganzen B. G. A study of freshwater mollusks in the lower reach of the Taz River basin revisited // Hydrobiological Journal. 1973. V. 9. No. 5. P. 61-63.
4. Sviridenko B. F., Dolgin V. N., Efremov A. N., Soloviev N. N. Hydrobiological features of the forest tundra zone part of the Taz River (Yamal-Nenets Autonomous District) // Collection of Scientific Papers of the Department of Biology. Surgut, 2010. No. 7. P. 87-97.
5. Dolgin V. Ancient stock right-Ob and Yenisei formation history // Tomsk State Pedagogical University Bulletin. 1999. Issue 7 (16). C. 34-38.
6. Dolgin V. N. Biotope distribution of freshwater mollusks in the water bodies of North Siberia // Tomsk State Pedagogical University Bulletin. 2003. Issue 4 (36). P. 55-61.
7. Dolgin V. N. Biological diversity of mollusks in North West Siberia // Current Problems of Siberian Hydrobiology. Tomsk: Tomsk University Press, 2001. P. 34-35.
8. Dolgin V. N. Latitudinal zonality of mollusks and the ecological biogeographic zoning of the Siberian North // Tomsk State Pedagogical University Bulletin. 2002. Issue 2 (30). P. 40-46.
Dolgin V. N.
Tomsk State Pedagogical University.
Ul. Kievskaya, 60, Tomsk, Russia, 634061. E-mail: dolgin@tspu.edu.ru
Sviridenko B. F.
Surgut State University.
Pr. Lenina, 1, Surgut, Tyumen region, Russia, 628400.
E-mail: bosviri@mail.ru
Received 16.11.2010.
В. Н. Долгин, Б. Ф. Свириденко ПРЕСНОВОДНЫЕ МОЛЛЮСКИ БАССЕЙНОВ РЕК ПУР И ТАЗ (ЗАПАДНАЯ СИБИРЬ)
Рассматривается история изучения и приводятся сведения о современном видовом составе пресноводных моллюсков бассейнов рек Пур и Таз.
Ключевые слова: пресноводные моллюски, биотоп, распределение.
Долгин В. Н., доктор биологических наук, профессор.
Томский государственный педагогический университет.
Ул. Киевская, 60, Томск, Россия, 634061.
E-mail: dolgin@tspu.edu.ru
Свириденко Б. Ф., доктор биологических наук, профессор. Сургутский государственный университет.
Пр. Ленина, 1, Сургут, Тюменская область, Россия, 628400. E-mail: bosviri@mail.ru