İki rheocrene kaynaktaki (Bolu,Türkiye) ostrakod (Crustacea) türlerinin karşılaştırmalı ekolojisi

Increasing human disturbances on freshwater habitats can cause loss of species and habitats. Conservation studies on these habitats deduced bioindicator species concept. Besides, species of Ostracoda with their relatively unchanged habitat preferences from past to present and sensitivity to ecological conditions increase their importance on the usage as bioindicator species.In this study two rheocrene springs were selected in the Bolu region, both having almost the same latitude and altitude. They spread nearly 50-60 meters down from the sources. Two stations were selected in both of these study sites. Materials were collected from these four stations in fifteen months between November 2002 and November 2004. As a result, total of ten species (Darwinula stevensoni, Candona neglecta, Cypria ophthalmica, Ilyocypris bradyi, Eucypris lilljeborgi, Prionocypris zenkeri, Herpetocypris chevreuxi, Psychrodromus olivaceus, Heterocypris incongruens, Scottia pseudobrowniana) were recognized. Among these species Scottia pseudobrowniana was recorded second time in Turkey from the first station of Çaygökpınar spring. Eucypris lilljeborgi is also a new report for the ostracod fauna of Bolu. On the other hand, there was a dominancy of C. ophthalmica, P. zenkeri, I. bradyi and C. neglecta in the second stations of both Çaygökpınar andÇetin Bey springs. Herpetocypris chevreuxi was only found in the stagnant waters of the second station of Çetin Bey spring. Both species, C. ophtalmica and D. stevensoni were collected from the first and second stations of Çaygökpınar spring.Statistical analyses revealed that similarities among the first stations of Çetin Bey and Çaygökpınar springs and again among the second stations of those springs are much more than the similarities between the first and the second stations of the same spring. Optima, tolerance, and Environmental Tolerance Index (ETI) values put forward the ecological characteristics of species according to the environmental variables. Spearman Correlation Analysis showed that I. bradyi had positive relationship with C. ophthalmica, the same result is also observed in the UPGMA dendogram. However, it did not display a significant relationship between environmental variables and species occurrence.Key Words: Ostracoda (Crustacea), Ecology, Springs, Taxonomy, Distribution, Comparative Ecology, Statistical Analyses