Cnidarian fauna of relict Lakes Baikal, Biwa and Khubsugul

Abstract

In relict Lakes Baikal, Biwa and Khubsugul three orders: Hydrida, Athecata and Limnomedusa (?) of the class Hydrozoa were found. In Lake Baikal, only representatives of Hydrida, such as Pelmathohydra baikalensis (endemic of Lake Baikal), P. oligactis and Hydra circumcincta were found (the last two species had not been found there before. Recent studies of the phylum Cnidaria in Lake Biwa showed the presence of Pelmatohydra oligactis and a representative of the family Clavidae which has been treated as a new species, Pachycordyle kubotai. In Lake Khubsugul a single representative of Hydrida has been found so far which is suggested to represent a new species of Pelmatohydra. According to techniques described earlier air-dried chromosome slides were prepared. The karyotype of P. kubotai were studied using conventional chromosome staining (by 6–10% Giemsa in the Sørensen’s buffer, pH 6.8), whereas karyotype of P. baikalensis was studied using conventional and C-banding techniques. C-banding to reveal highly repeated DNA followed the protocol by Sumner (1972).