Age, Growth, Length-Weight Relationship and Reproduction of Chub, Squalius cephalus (L., 1758) in Upper Akcay River, Turkey

Abstract

For the first time, we investigate the aspect of bio-ecological of chub (Squalius cephalus L., 1758) in upper Akcay River (Buyuk Menderes Basin) including the age, growth, length-weight relationship and reproduction. The study was conducted in upper Akcay River between June 2012 and May 2013. Monthly data showed that native fish chub were aboundantly with other native fish (Acanthobrama mirabilis) in upper Akcay River. The age distribution for both females and males of S. cephalus population was between I-VII, and the second age group was found at maximum rate of 30.60%. Their fork lengths and weights ranged between 6.0-22.8 cm and 3.7-134.62 g for females; 6.1-22.1 cm and 2.7-110 g for males, respectively. The growth parameters of the von Bertalanffy equation were found as Lt=34.71 {1-e(boxed times 0.116(t+0.867))] for females and Lt=32.87 [1-e(boxed times 0.127(t+0.717))] for males. The length -weight relationships were estimated to be WT=0.0269 FL2.720(R-2=0.981) for females and WT=0.0251 FL2.7535 (R-2=0.983) for males. Weight increased negatively allometrical with the fork length for both sex. The average condition factor for females was calculated as 1.37 while 1.32 for males. The sexual maturity age of females and males was determined to be II age group and first sexual maturity. The total length was found as 11.33 cm for female and 10.89 cm for male. According to the trends of GSI values, it was assumed that their season of reproductivity was between March and May.