Bolu bölgesi (Türkiye) tatlısu osrakodlarının (Crustacea) ekolojik özelliklerinin belirlenmesi

The study includes samples gathered from 144 different aquatic environments randomly chosen from 9 counties affiliated to Bolu region on June- August 2006. In determining the worksite, special attention is paid in designating zones of varied features in order to attain general distribution. Hence; stations of varied features such as pond, spring, lake, creek, trough, pool etc. are included in the worksite. A total of 41 taxa pertaining to 21 genus (Psychrodromus olivaceus, Ps. fontinalis, Candona neglecta, C. candida, C. weltneri, C. sanociensis, C. lactea, Pseudocandona compressa, Pse. albicans, Pse. cf. semicognita, Fabaeformiscandona fabaeformis, F. cf. breuili, F. balatonica, F. brevicornis, F. protzi, F. latens, Schellencandona cf. belgica, Heterocypris incongruens, H. salina, H. rotundata, Ilyocypris bradyi, I. gibba, I. getica, I. inermis, Herpetocypris chevreuxi, Hr. reptans, Hr. brevicaudata, Potamocypris villosa, P. similis, P. fulva, P. smaragdina, Cypridopsis vidua, Cypria ophthalmica, Scottia pseudobrowniana, Prionocypris zenkeri, Trajancypris serrata, Cyclocypris laevis, Eucypris virens, Physocypria kraepelini, Cavernocypris sp., Darwinula aff. stevensoni) are defined. As to the aforementioned species, while for the first time in literature the bisexual population of I. inermis is detected, 12 new species (C. weltneri, C. sanociensis, C. lactea, F. cf. breuili, F. balatonica, F. brevicornis, F. protzi, F. latens, Schellencandona cf. belgica, Pse. cf. semicognita, P. similis, P. smaragdina) are registered to Turkish Ostracoda fauna. Among these Schellencandona is a newly recorded genus for non-marine Ostracoda fauna of Turkey. Besides, six species (Herpetocypris brevicaudata, Cyclocypris laevis, Ilyocypris getica, Trajancypris serrata, Potamocypris fulva, Psychrodromus fontinalis) are recorded for the second time in Turkey. Furthermore, 17 species which determined in this study (C. weltneri, C. sanociensis, C. lactea, F. cf. breuili, F. balatonica, F. brevicornis, F. protzi, F. latens, Schellencandona cf. belgica, Pse. cf. ssemicognita, Hr. brevicaudata, H. salina, H. rotundata, P. similis, P. smaragdina, Cyclocypris laevis, Trajancypris serrata) are first record for the Bolu region. According to Unweighted Pair Group Mean Averages (UPGMA) results, 11 species have shown relationship in five groups according to their stations. According to the species distribution among nine counties, 75% of species analogy is recorded between Yeniçaga and Göynük, while Seben and the central region have shown the least amount of analogy, being 20%. While the species with the highest toleration level, as primarily to dissolved oxygen, water temperature and redox potential, is recorded as H. incongruens, the species with the highest tolerance to pH change is C. candida, yet another cosmopolitan species. Hr. chevreuxi which shows a cosmopolitan distribution at least in Holarctic region is recorded as the species to have the highest tolerance level against electrical conductivity. Therefore; the results generally support the idea that advocates cosmopolitan species to have high tolerance levels. According to the results of Spearman Correlation Analysis between species and environmental variables, two species (Pro. zenkeri, Ps. fontinalis) have shown negative correlation with pH, while the same species show a positive correlation with redox potential (SHE). Among the species, only C. candona and Ps. olivaceus have shown a significant positive correlation with electrical conductivity (P<0.05). While some species have shown considerable statistical correlation among each other, the relation among environmental variables (pH- redox potential for instance) proves to be as anticipated. The first axis of the Canonical correspondence analysis (CCA) can only define 52 % of the relationship between species and environmental variables (with 4.3 % of error). According to the analysis five most effective variables on species are as follows; temperature, redox potential, dissolved oxygen, pH and electrical conductivity. The results have generally reconciled with ETI and Spearman correlation results. Key Words: Ostracoda, Ecology, Tolerance and Optimum, ETI, Bolu.