Fossil and Recent Distribution and Ecology of Ancient Asexual Ostracod Darwinula stevensoni (Ostracoda, Crustacea) in Turkey

In order to determine distribution, habitat and ecological preferences of Darwinula stevensoni, data gathered from 102 samples collected in Turkey between 2000 and 2017 was evaluated. A total of 1786 individuals of D. stevensoni were reported from eight different aquatic habitats in 14 provinces in six of seven geographical regions of Turkey. Although there are plenty of samples from Central Anatolia Region, recent form of the species was not encountered. Unlike recent, fossil forms of species were encountered in all geographic regions except Southeastern Anatolia. The oldest fossil record in Turkey was reported from the Miocene period (ca 23 mya). Species occurred in all climatic seasons in Turkey. D. stevensoni showed high optimum and tolerance levels to different ecological variables. Results showed a positive and negative significant correlations of the species with pH (P<0.05) and elevation (P<0.01), respectively. It seems that the ecological preferences of the species are much wider than previously known. Our results suggest that if D. stevensoni is used to estimate past and present environmental conditions, attention and care should be paid on its ecology and distribution