Estimation of basal HSP70 levels in two thermotolerant Baikal amphipod species from different thermal habitats

In two thermotolerant amphipod species from Lake Baikal - Eulimnogammarus cyaneus (Dybowsky, 1874) and Gmelinoides fasciatus (Stebbing, 1899), sampled at different habitat temperatures - the level of Hsp70 was estimated. Both species have a significantly higher Hsp70 level, than other dominant amphipods within the littoral zone of the lake. Baikal endemic species E. cyaneus, sampled within a range of thermal condition - from 2 to 22°C did not show any significant correlation between the basal Hsp70 level and sampling temperature. However, the level of Hsp70 in G. fasciatus depended the habitat temperature and was significantly higher in amphipods sampled at the hot spring at 29°C, than in the open shore of southern Baikal at 8°C. The observed results can be explained by different evolutionary age of the studied species, indicating that the putative tertiary relict G. fasciatus has adaptive advantages allowing this species widely distribute beyond its habitat.