Distribution of aquatic oligochaetes (Annelida, Clitellata) of high-elevation lakes in the Eastern Black Sea Range of Turkey


Abstract: Many large and small lakes of varying depths are present in the Eastern Black Sea Range of Turkey, the nation's third most important glacial region following the Ağrı and Cilo-Sat mountain ranges. During the present study, 6 expeditions to collect aquatic oligochaetes from these lakes were conducted in July and August of 2005, 2006, and 2007; qualitative and quantitative samples were collected from 59 glacial lakes. We present and analyze the dominancy and distribution of aquatic oligochaete assemblages and their relation to environmental factors (temperature, dissolved oxygen, pH, electrical conductivity, salinity, turbidity, PO_4^{-3}-P, HCO_3^{-}, organic carbon, hardness, Ca^{2+}, Mg^{2+}, Si, water depth, and altitude) using classification and ordination techniques. Canonical correspondence analysis (CCA) was used to characterize the relationship between oligochaetes and the environmental variables. As a result, we determined the 4 most important environmental variables (elevation, water depth, dissolved oxygen, and temperature) affecting species distribution in general. Sampling localities were clustered into 8 groups with the unweighted pair-group method with arithmetic mean (UPGMA) based on physicochemical characteristics. The relationships between the total number of individuals and environmental measurements were determined by a simple analysis of variance (ANOVA) test. The results of our analyses suggest a significant positive correlation between altitude (P < 0.05; F = 2.994) and the total number of individuals.

Keywords: Oligochaeta, Clitellata, Haplotaxidae, Naididae, Enchytraeidae, Lumbriculidae, Tubificinae, Naidinae, Eastern Black Sea Range, Turkey, glacial lakes

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