Danube Crayfish Astacus leptodactylus (Eschscholtz, 1823) from Ţaga Mare Lake – Size and Population Structure

Abstract

Abstract In this study the structure of the Danube crayfish (Astacus leptodactylus) population from A¢aga Mare Lake, Cluj County was analyzed. According to the study results, three age categories (2+, 3+ and 4+) were identified for the Danube crayfish specimens. Numerically, females are more numerous than males, the sex ratio between males and females being as follows: SR2+ = 0.33; SR3+ = 0.33; SR4+ = 0.86. In terms of body size, males are better developed, except for their abdominal segments, where females are better developed due to the female reproductive function.