Observations on biological properties of the chub, Leuciscus cephalus and environment conditions in the Çaparlıpatlak Pond (Balikesir), Southern Marmara Region, Turkey

Abstract

This investigation was conducted in the Çaparlıpatlak Pond, based on a 1-year study involving 431 specimen. The age composition of this species ranged between I and VI with the dominance of fourth age group in the population. Individuals were composed of 36.60% males and 63.40% females. The male and female ratio was 1:1.71 (M:F). Female individuals attained greater size than males. The largest female captured was 21.5 cm FL while the largest male was 20.2 cm FL at the same age, VI. The length– weight relationship was given by W  =  0.0648 · L^2.44 (where W= weight in g; FL  =  fork length in mm). Age at length data were inferred by modal analysis of the length–frequency distributions. The parameters of the fitted Von Bertalanffy growth equation were L∞ = 23.66 cm; K = 0.30 yr⁻¹; to = −0.95 yr. Macroscopic examination of the gonads, and analysis of the monthly values of the gonadosomatic index indicated that reproduction occurs in spring and early summer, with a maximum between April and June, when water temperatures are high.