Patterns of genetic diversity in Mediterranean supralittoral amphipods (Crustacea, Amphipoda)

Abstract

Allozymic variation at 26 loci was investigated in 9 populations of Talitrus saltator and 4 populations of Talorchestia deshayessi from different Mediterranean area. Within T. saltator a considerable amount of genetic differentiation was found, allowing the recognition of three genetically different groups of populations (Tyrrhenian, Adriatic and Wastern-Mediterranean) with a mean Dnei78 value of 0.334. With regards to T. deshayessi the population from the Maltese Archipelago was the most differentiated with a Dmean of 0.228 compared to populations believed to be conspecific on morphological grounds. These results are compared with allozymic data from our laboratory on 5 genera and 10 species of supralittoral amphipods. The observed pattern of genetic variation could be the result of the intrinsic ecological features of the species as well as environmental differences among the collecting sites.