Ecology of Freshwater Ostracoda (Crustacea) from Lakes and Reservoirs in Bolu, Turkey

ABSTRACT

Freshwater ostracods are important for interpreting the water quality of aquatic habitats. However, using ostracods in this way requires knowledge of their ecology and habitat preferences, particularly because species may show different responses to different ecological conditions. I documented ecological requirements of five ostracod species and their distribution in ten similar-sized lakes and reservoirs in Bolu, Turkey. Five species (Darwinula stevensoni, Cypria ophthalmica, Cypridopsis vidua, Cyclocypris ovum, Fabaeformiscandona fabaeformis) were found from natural lakes, while no ostracods were encountered from reservoirs. A canonical correspondence analysis suggested that salinity, temperature, redox potential, and pH were the four most influential factors on the species habitat preference in these lakes. These results were also supported with unweighted pair group mean averages (UPGMA) that also showed ostracod preference for certain ecological conditions in these lakes was mostly species-specific, depending on the changes in the levels of variables. UPGMA analysis for clustering of species and environmental data revealed three main species assemblages. The first group was represented by a single species, F. fabaeformis, whose occurrence was closely related to water hardness. The second group included two species, D. stevensoni and C. ophthalmica, that were found in relatively alkaline waters with moderate temperature. The third group was represented by two species, C. vidua and C. ovum.