Distribution characteristics and responding to ecological environment of terrestrial ostracod on the Qinghai-Tibetan Plateau

Terrestrial ostracods can adapt to fresh waters, brackish waters, salt waters and hypersaline waters, and most of them in shallow waters (river, springs, ditches and swamps) and lakes. It is very sensitive to the physical and chemical changes of the host water. The Qinghai-Tibetan Plateau (QTP) not only directly influences the formation and evolution of monsoon climate in China, but also is a sensitive area of climate change in China and the world. Distribution characteristics of terrestrial ostracod in surface sediments of different regions on the QTP were analyzed statistically, and the response of ostracods to ecological environment in different water environments (salinity, pH and water depth) was discussed. The results show that total of 21 genus and 67 species are discovered on the QTP, among which Candona candida, Ilyocypris bradyi, Eucypris inflata, Limnocythere dubiosa, Limnocythere inopinata, Paracypricerus angulata, Leucocytherella sinensis and Leucocythere mirabilis are common species. The four types of water environment including lakes, rivers, depressions and wetlands, among which the number of ostracods is the most abundant in lakes, accounting for 19 genus and 62 species. The common ostracod species in the northeastern (Qilian Mountains and Qaidam Basin), the northern (Kunlun Mountains), the western and the southern part of the QTP are different greatly, which may be closely related to the altitude, pH value and salinity of regional water bodies. The abundance of ostracods in fresh water and brackish water is higher than that in saline waters and salt lakes, with 41 species in 17 genera and 42 species in 13 genera, respectively. Limnocythere dubiosa (0.52-90.6 g/L) and Leucocythere mirabilis(0.51-174.63 g/L)can be discovered in fresh water, brackish water and salt lake, which have the wider range of adaptation salinity. Ostracods have the maximum species diversity in water bodies with pH values of 8.0-10.0, indicating that most of which are basophilic. Genus's diversity of terrestrial Ostracods on the QTP decreases with increasing water depth. In shallow lakes (0-15 m), ostracods are the most abundant with 52 species in 17 genera, and Candona candida(0.2-80 m)and Leucocythere dorsotuberosa(0.3-110 m)are distributed from lakeside to deep lake, and both of them have deeper depth adaptability range. © 2022 by Journal of Lake Sciences.