Some Biological Properties of the Leuciscus cephalus (L., 1758) Population Living in Karakaya Dam Lake in Malatya (Turkey)


Abstract: The sex distribution, growth in length and weight, growth rates and condition factors of Chub (Leuciscus cephalus (L., 1758)) in Karakaya dam lake were examined. Females made up 63.64% and males 36.37% (1.75:1) of 527 samples. The females and males were in the I-VI and I-V age groups, respectively. The reproductive properties of L. cephalus such as spawning period, age at attainment of maturity, egg diameter and ovarium weight were investigated. Student's t test showed that differences in length and weight between females and males of the same age groups were statistically insignificant (P > 0.05). The growth, both in length and weight, was calculated according to the von Bertalanffy equation for females and males respectively: L_t = 37.8 [1-e^{-0.4125(t-(-1.0013))}], W_t = 775.3 [1-e^{-0.4125(t-(-1.0013))}]3.0272 and L_t = 35.45 [1-e^{-0.6062(t-(-0.1883))}], W_t = 590.5 [1-e^{-0.6062(t-(-0.1883))}]2.4878. The calculated length-weight relation for females was W = 0.013 L^{ 3.0272} and for males W = 0.0824 L^{2.4878}. The average condition factor was 1.42 ± 0.05 for females and 1.43 ± 0.25 for males. According to gonado-somatic index (I_G) results and the development of egg diameter, it was determined that the spawning period of L. cephalus occurs in May and June. Sexual maturity was attained in the third year. The mean diameter of ripe eggs was 1.06 mm and the mean number of eggs per gram of gonads was 1265.

Keywords: Leuciscus cephalus, growth, von Bertalanffy's parameters, length and weight relationships, condition factor, sexual maturity, spawning period, Karakaya dam lake

Full Text: PDF