HABITAT PREFERENCES OF AQUATIC OLIGOCHAETA (ANNELIDA) SPECIES IN THE LAKE DISTRICT (TURKEY)

In order to determine habitat preferences of aquatic Oligochaeta in the Lake District area of Turkey, quantitative sampling and measurements of some of the selected physicochemical variables were done seasonally from June 1999 to November 2000. Total of 45 Oligochaeta species were collected from 75 different habitats. Canonical Correspondence Analysis (CCA) explained 81% of the correlation among species and environmental variables with about % 32.5 of variance. Influential variables on the species distribution from most to least affective follow as water depth, Secchi depth, pH, dissolved oxygen, elevation, temperature, CaCO3=, electrical conductivity and salinity. Species were clustered into six groups with Unweighted Pair Group Mean Averages (UPGMA) analyses based on species occurrence. Overall, results suggest that each Oligochaeta species has species-specific habitat preferences although some of them overlap in their requirements.