Suppression of Artemia spp. (Crustacea, Anostraca) populations by predators in the Crimean hypersaline lakes: A review of the evidence

Artemia spp. play a key role in hypersaline ecosystems. Artemia can live in a salinity range from 10 to 300–340 g/L, but in water bodies where salinity is between 10 and 100 g/L, it may be absent. Is the absence of Artemia in some Crimean lakes determined by the presence of predators or by salinity? To answer this question field long-term and experimental data collected in the Crimean lakes were used. With the least probability, the populations of Artemia existed in the lakes with a salinity of up to 50 g/L or above 300 g/L. Self-reproducing Artemia populations (all age stages) were most likely (≥80% of occurrence) noted in the salinity range of 150–200 g/L. Long-term monitoring in two lakes showed that in different years, a significant negative correlation of Artemia abundance with the numbers of amphipod Gammarus aequicauda and ostracod Eucypris mareotica was found in both lakes. This correlation can be explained by ostracod and amphipod predation on Artemia. In years without predator populations, the number of Artemia was higher by several times. Experiments showed that these amphipods and ostracods consume brine shrimps of different developmental stages. There are at least 12 crustacean species, 5 insect species, and 2 fish species, all listed in this paper, which inhabit Crimean hypersaline waters and can eat Artemia. Their predation on Artemia often is a main cause of its absence in the salinity range from 10 to 150 g/L.