Reproductive biology of danube bleak, Alburnus chalcoides (Güldenstädt, 1772) in Tödürge lake (Sivas, Turkey)

Abstract

In this study, some biological properties such as the age and sex distributions, age at first spawning, fecundity, dating of the spawning, minimum fishing size and closed period for the fishery of A. chalcoides living in Tödürge Lake, which is one of the important wetlands of Turkey, were determined. In total, 456 specimens of bleak were caught between April 1994 and November 1994. The age of sexual maturity was found to be II for male individuals and II-III for female individuals. The smallest female and male with mature gonads had 147 mm fork length and 39.5 g body weight and 119 mm and 20.1 g, respectively. It was determined that the specimens of A. chalcoides started to spawn in May and continued until the end of July. The number of eggs in the ovary and egg diameter ranged from 2265 to 16540 and from 0.10 to 1.35 mm, respectively. Fishing must be prohibited during the spawning period to ensure economic evaluation and the sustainability of the population. The smallest prey size allowed for commercial fishing must be based on the length and weight averages (158 mm; fork length, 49 g; body weight) of the age group III. © 2011 Friends Science Publishers.