Study on the narrow-clawed crayfish Astacus leptodactylus Eschscholtz, 1823 (Crustacea: Decapoda: Astacidae) population in a sand-pit Lake near the village of Boshulya (Upper Thracian Lowland, Bulgaria)

The paper represents the results of investigation on the narrow-clawed crayfish population in the sand-pit Lake near village of Boshulya (Upper Thracian Lowland, Bulgaria). The number of crayfish (925) caught showed a high density of their population (mean CPUE=14.69). Individuals with a body weight between 20.1 and 30.0 g predominated the sample. They were 38% of the total catch. With the lowest percent (1%) were the groups with body weight 70.1 – 80.0 g and this one over 80 g. The average ovarian eggs number (absolute fecundity) was 228.85 (min. 144, max. 294).