Oligochaeta from the abyssal zone of Lake Baikal (Siberia, Russia)
Martin, P.; Martens, K.; Goddeeris, B. (1999). Oligochaeta from the abyssal zone of Lake Baikal (Siberia, Russia), in: Healy, B.M. et al. Aquatic Oligochaetes: Proceedings of the 7th International Symposium on Aquatic Oligochaetes held in Presque Isle, Maine, USA, 18-22 August 1997. Developments in Hydrobiology, 139: pp. 165-174. https://dx.doi.org/10.1007/978-94-011-4207-6_16 In: Healy, B.M.; Reynoldson, T.B.; Coates, K.A. (Ed.) (1999). Aquatic Oligochaetes: Proceedings of the 7th International Symposium on Aquatic Oligochaetes held in Presque Isle, Maine, USA, 18-22 August 1997. Reprinted from Hydrobiologia, vol. 406. Developments in Hydrobiology, 139. Springer Science+Business Media: Dordrecht. ISBN 978-94-010-5829-2; e-ISBN 978-94-011-4207-6. XIV, 290 pp. https://dx.doi.org/10.1007/978-94-011-4207-6, more In: Dumont, H.J. (Ed.) Developments in Hydrobiology. Kluwer Academic/Springer: The Hague; London; Boston; Dordrecht. ISSN 0167-8418, more |
| Abstract | Lake Baikal is unique because the water circulation carries oxygen to its deepest point (1637 m), which makes it the only freshwater lake in the world with an inhabitable abyssal area. The sampling of the abyssal of the Lake was recently made possible, allowing a study of the bathymetric and vertical distribution in the sediment of Oligochaeta. Samples were taken with a Reineck box corer and subsamples were extracted and subsequently divided into slices. Factors likely to affect oligochaete abundance with depth and in the sediment were then evaluated. Identification to the species-level allowed discussion of the possible role of the abyss of Lake Baikal in the origin of oligochaete taxa and to assess if genuine deep-water taxa exist. Abundance of Oligochaeta generally follows an exponential decline with depth. An exception was one station located near a deep hot vent. In the abyssal area, all families of Oligochaeta are concentrated near the surface of the sediment. While there are generally no Naididae below 50 m, Tubificidae, Lumbriculidae, Propappidae, Enchytraeidae and Haplotaxidae are present at all depths. Evidence suggests, for the first time, that food abundance is a limiting factor of oligochaete distribution. The possibility of a genuine deep-water oligochaete fauna in Lake Baikal cannot be excluded but the low densities and the very small sizes of animals in this environment might have caused biased samples. |
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