S.A. Erguden - Fisheries Department, Imamoglu Vocational School, Cukurova University, TR ۰۱۷۰۰, Imamoglu, Adana, Turkey

The population structure of Aphanius mento in the Seyhan Reservoir was studied on the basis of ۸۳۴ fish specimens (۵۱۶ males and ۳۱۸ females) caught on a monthly basisbetween September ۲۰۱۳ and August ۲۰۱۴. Fish were collected using dip nets of tulle with a ۱mm mesh size. The maximum age of fish was found to be ۴ years for both sexes combined, the ۱ year old age group comprised ۶۲.۲۰% of male samples. The overall sex ratio of females to males was ۱:۱.۶۲. Von Bertalanffy growth parameters were L∞=۵۴.۳۳ mm, K=۰.۳۹۹ year-۱,  t۰ =-۱.۱۶۸ years for females, L∞ =۵۲.۷۲ mm, K=۰.۳۹۷ year-۱, t۰=-۱.۱۳۷ years for males, and L∞=۵۶.۵۰ mm, K=۰.۳۸۶ year-۱,                t۰=-۱.۲۵۷ years for both sexes. The length (TL) - weight (W) relationship was W= ۰.۰۰۰۵۱xTL۲.۶۳۵, (r= ۰.۹۶۵) for males, W=۰.۰۰۰۸۸xTL۲.۴۶۴, (r= ۰.۹۸۷) for females and W=۰.۰۰۰۶۶xTL۲.۵۵۴, (r = ۰.۹۷۴) for both sexes. Condition factor ranged from ۱.۶۹۶ for males and ۱.۶۱۳ for females to ۱.۶۶۴ for both sexes. The mean condition factor (CF) was not significantly different between the sexes among all fish during different months (p>۰.۰۵). The present study represents the first comprehensive information on the population structure of A. mento in the Seyhan Reservoir. The results of this study will contribute to the population management and conservation of this species and be useful in increasing knowledge on its ecology and biology.

Aphanius mento, Growth parameters, Condition, Southeastern Mediterranean