THE RESULTS OF STUDYING DIAPAUSING EGGS (CYSTS) OF BRINE SHRIMP ARTEMIA ON THE BOTTOM OF HYPERHALINE LAKES OF THE ALTAI TERRITORY

Abstract

The results of studies of bottom Artemia cysts in Kuchukskoe Lake and Bolshoe Yarovoe Lake of the Altai Territory in 2020 are presents. Artemia cysts at the bottom of lakes were observed all year. This number depended on the type of soil. The biomass of bottom cysts in Kuchukskoe Lake was 154.2 tons in spring, of which available and externally-whole – from 11.8 to 25.2 tons. Bottom Artemia cysts are not available on 27% of the lake area in Kuchukskoe Lake due to the high salinity of the water and salt precipitation. The viability of cysts from shallow bottom areas was 8.9% in spring. In Kuchukskoe Lake the main role in the formation of first generation Artemia in spring is played by cysts from accumulations on the coast, washed away by the runoff of melt water. The deep water of Bolshoe Yarovoe Lake determines the peculiarities of the temperature regime in spring, which prevents the rise of Artemia cysts from the bottom from depths of more than 7.0 m. Significant silt deposits at the bottom of the lake are an aggressive environment for cysts, which is shown by the presence of different group of quality: externally-whole, with defective chorion, gray or black color. The biomass of bottom cysts in Bolshoe Yarovoe Lake was 38934 tons in autumn of 2020, which exceeds the reproductive capacity of the Artemia population in one year. This proves the long-term period of accumulation of cysts at the bottom and their incomplete participation in the formation of the Artemia first generation in spring. The maximum hatching of nauplius from bottom cysts in spring from a depth of more than 9.0 m was 16%, from a depth of 8.0 m – 26%.