Comparative analyses of Astacus leptodactylus morphological characteristics from Croatia and Armenia

Narrow-clawed crayfish, Astacus leptodactylus is a native European freshwater crayfish species, also distributed in Croatian freshwater systems belonging to the Black Sea drainage. Its taxonomical status is still in the process of change and discussion, and the data on morphological, molecular, ecological and zoogeographical characteristics of this species are scarce. Therefore, comparative analyses of morphological characteristics were applied with the aim to contribute to the knowledge on the morphometrical and meristical characteristics of A. leptodactylus. Recent research proved that measurements of a large number of morphometrical characteristics, in combination with multivariate statistical analysis, could provide a good instrument for identification and differentiation between populations. In this research altogether 143 animals were analysed (121 from two Croatian populations and 22 from Armenia). 22 morphometrical characteristics and 4 meristical characteristics, per crayfish, were measured. It was found that males and females differ between populations in measured meristical and morphometrical characteristics. None of recorded meristical characteristics proved itself to be reliable characteristic for distinguishing populations. From measured morphometrical characteristics the most discriminant characteristics for separating males from different populations were those describing carapace shape and for females those that describe shape of the claws.