Notes on the morphological characteristics of Austropotamobius torrentium (Schrank) from Croatia and Macedonia

The aim of this research was to verify if morphological differences between distinct stone crayfish (Austropotamobius torrentium) populations exist. For the purpose of morphological comparison between populations two morphometric and two meristic characteristics were chosen. The length of cephalothoraxe (C), rostrum (R) and apex (A) were measured. In statistical comparison index of rostrum and cephalothorax (R%C = R / C x 100) and index of apex and rostrum (A%R = A / R x 100) were used. The position and number of spines on the merus of the third maxilliped, both for the left and the right maxilliped were also recorded. The position of spines was categorised as central (on the central part of the merus), distal (away from the basis, on the second half of the merus), and ubiquitous (along the whole length of the merus). Altogether 101 stone crayfish, originating from one Macedonian and 11 Croatian populations, were examined. Recorded differences in morphometric and meristic characteristics between the populations are presented and discussed.