Morphological Variability and Sexual Dimorphism of Danube Crayfish Pontastacus leptodactylus Eschscholtz, 1823 from the Vrbas River

Abstract

The paper presents data on morphological variability and sexual dimorphism of Danube crayfish (Pontastacus leptodactylus) from the Vrbas River in Srbac. Crayfish were captured with hand made traps from October 2018 to May 2019. A total of 35 crayfish were caught, of which 22 males and 13 females. The dimensions of eight morphometric characteristics: body weight (W), body length (TBL), claw length (CLL), cephalothorax length (CEF), carapace width (CPW), abdomen length (ABL), rostrum length (ROL) and rostrum width (ROW) were analyzed, both in males and females. Also, for all caught specimens condition factor was determined. The results of the morphometric character measurements fit into the range of variation and represent the first data for the investigated area. By using t-test, it was noted that there are significant differences between the sexes for W, TBL, CLL, CEF, ABL and ROL, which is explained by the pronounced sexual dimorphism of Danube crayfish.