Sexual dimorphism in Branchipus schaefferi Fieher, 1834 (Anostraca: Branchiopoda: Crustacea) from Serbia

Abstract

Quantitative information regarding sexual dimorphism in large branchiopod crustaceans is insufficient, especially for the Balkans. Here we present the data obtained on several morphometric and meristic characters in six populations of Branchipus schaefferi. Male-biased sexual dimorphism was shown in the length of head and cercopods, whereas females had longer thorax and abdomen, absolutely and relative to the total body length. Among the meristic traits, significant difference between the sexes was found only in the number of hairs on the ventral side of the abdomen, with higher average value in females. The results differed among the analyzed populations, indicating geographic variability in morphology and degree of sexual dimorphism in this species. The exact roles of various body parts and sensory elements in mating process in the genus Brandiipus are not yet fully explained. Results show.,,that quantifiable differences between males and females exist, can be used as criteria for sex discrimination and are determined by the interplay of various types of selection.