Morphometrics of crayfish species and relationship to the trophic level of waterbodies

Investigations on the relationships between morphometrics of different crayfish species and the trophic levels of their habitats were carried out. Noble crayfish Astacus astacus (Linnaeus, 1758) were caught in mesotrophic lakes, eutrophic lakes and mesotrophic Lakes with oligotrophic elements. Narrow-clawed crayfish Astacus leptodactylus Eschscholtz, 1823 were caught from a big shallow eutrophic lake (550 ha, mau. depth 5 m) and a mesotrophic lake. Spiny-cheek crayfish Orconectes limosus (Rafinesque, 1817) were obtained from a mesotrophic lake and an eutrophic river. The following morphometric parameters of crrom a big shallow euayfish were measured: total length, weight, and length and width of carapace, abdomen, chelae and rostrum. The most significant differences for the investigated crayfish species in waterbodies of different trophic levels were found in the carapace length. The highest correlation was between carapace length and weight. Significant differences were also found between morphometric data of crayfish of the same species in waterbodies of different trophic levels.