Determination of some population parameters of freshwater lobster (Astacus leptodactylus Eschscholtz, 1823) in Ulugöl, one of the Bafra fish lakes

In this study, total 378 crayfish were sampled from Bafra Ulugöl between July 2010 and July 2011. Biometric measurements were done such as eggs, meat efficiency, disease and anomalies. In this research, total 398 of crayfish, were examined 198 femaleand 180 male individual identified and the monthly difference between sex ratios were insignificant (p>0.05). Length frequency distribution of crayfish were examined and cephalothorax length was 22-83 mm, total length was 80-156 mm. Average cephalothorax length was 50.96±0.46 mm for female, 51.31±0.66 mm for male and51.13±0.40 mm for all individuals. Average abdomen length was 52.36±0.49 mm for female, 49.26±0.62 mm for male and 50.87±0.40 mm for all individuals. The width of female crayfish abdomens was larger than male crayfish abdomens (p<0.05). However,male crayfish?s cephalothorax length, nipper length and nipper width were greater than female crayfish (p<0.001). Live body weight was varied between 14.38 g and 105.03 g,and average weight was 38.26±0.73 g, respectively. The average weights of female 35.63±0.73 g were lower than average weights of male 41.12±1.27 g (p<0.05). There was a strong linear correlation between height and weight (r =0.91).The minimum weight of egged crayfish was 28.24 g, maximum weight of egged crayfish was 59.50 g and average weight of egged crayfish was 41.73±1.09 g. The crayfish with eggs had average 192.90±9.94 units per individual eggs of with, maximum number of eggs were 368, minimum number of eggs were 50 carried, in the unit weight (1 g) calculated the number of eggs per 4.62±0.21 units. Total weight peregg was 3.35±0.19 g and average egg diameter was 2.17±0.03 mm, respectively. The amount of male crayfish abdomen flesh 3.49±0.14 g have been found significantly lower than female crayfish abdomen flesh 3.59±0.13 g. Crayfish abdomen meat,included 81.27% moisture, 1.47% crude ash, 0.81% crude fat and 16.45% crude protein.Keywords: Crayfish, Astacus leptodactylus, Ulugöl, Morphometric analysis,Meat yield, Efficiency of egg