Seben taşlıyayla göleti (Bolu, Türkiye) ostrakoda (crustacea) faunasının mevsimsel dağılımı ve ekolojik özellikleri

In order to understand seasonal distribution and ecology of non-marine ostracod species, 15 stations around Seben - Taşlıyayla Lakelet (reservoir) were monthly visited between August 2013 and September 2014. Accordingly, total of eight species (Candona weltneri, Cypridopsis vidua, Herpetocypris chevreuxi, Heterocypris salina, Heterocypris incongruens, Limnocythere inopinata, Potamocypris variegata, Koencypris ornata) were reported. The most common species C. vidua collected from almost all stations showed wide ranges of dissolved oxygen (DO) (4.53-9.47 mg/L), pH (7.53-9.47), water temperature (Tw) (6-27.3 °C), total dissolved solid (TDS) (0.0235-0.1021 mg/L) and electrical conductivity (74.4-127.4 μS/cm) while H. chevreuxi, L. inopinata, H. salina, P. variegata and H. incongruens displayed the lowest TDS values. According to Ostracod Watch Model (OWM), several species exhibited a clear seasonal distribution; for example, C. vidua was common from June to December when C. weltneri was only found in March. Species richness was highest in autumn season with seven species. Regression models revealed significantly positive correlation between air and water temperature (P<0.01). Among the species, six are cosmoecious species, having high levels of tolerances to different environmental variables and with wide geographical ranges. Accordingly, the ratio between numbers of noncosmopolitan to cosmopolitan species or so called "pseudorichness ratio" was 0.33, suggesting the reservior is in the early succession stage.