Spatial and Seasonal Variations in Condition, Somatic Index and Length-Weight Relationship of Capoeta banarescui (Cyprinidae) from The coruh River, Northeastern Anatolia, Turkey

The spatial and seasonal variations in some growth parameters of Capoeta banarescui have been studied by considering environmental factors. A total of 1993 fish was caught by electro fishing monthly from March 2001 to February 2002 at five different stations through the upper coruh River. Condition factor did not significantly differ among males, females, and juveniles but it was affected by study sites. Somatic index, varied spatially with lowest value recorded in Nihak (1.254) and highest value in Maden (1.342). Condition factor and somatic index had similar monthly pattern, with some minor exceptions depending on the study sites and the sampling periods. b value of length-weight relationship varied between 2.729 and 3.288. While fish from Kirik and Nihak showed negative allometric growth those from the other 3 sites had isometric growth. The highest b values for both sexes were observed in early spring while the lowest values generally occurred in fall. While, pH, phosphate and silicate did not significantly change between the stations, significantly higher temperature values were observed in Nihak and Kirazli. Significantly higher nitrate concentration, with a value of 3.61mg/L was observed in Nihak. Ammonium concentrations in Bayburt, Kirazli and Nihak stations showed significant increase comparing Kirik and Maden stations. Turbidity was significantly influenced by the study sites; the highest value observed in Nihak (31.79 +/- 42.12 FAU).