New Records, Biogeography, and Habitat Protection Needs of Four Species of Potamon (Decapoda: Brachyura) in Greece

Objectives are to determine the occurrence of species of Potamon in eastern Crete and the Aegean Islands (Chios, Naxos, Paros, Mykonos, Tinos and Andros); generate phylogenetic relationships among species to propose a biogeographic hypothesis relative to current distributions of the four species of the freshwater crab genus, Potamon, in Greece; and comment on the need to protect habitat suitable for the survival of species of Potamon in the country. Our collections, made in areas not previously sampled by researchers, indicate the presence of Potamon fluviatile on Tinos, N axos, and Andros, and Potamon potamios from central to eastern Crete; and verified the presence of Potamon ibericum on Chios. Cladistic analyses resulted in a single parsimonious tree (CI=85, RI=75). Potamon in the Balkan peninsula and islands in the Mediterranean region is a monophyletic group composed of two main clades: Clade 1 (P.fluviatile andPotamon algeriense) and Clade 2 (P. ibericum and its sister group composed of Potamon rhodium and Potamon potamios). Vicariant events (e.g. marine transgression and regression, orogeny, volcanism) are hypothesized as major factors that have shaped current distributions of species of Potamon in the Balkan Peninsula, Asia Minor, and the islands of the North Aegean Sea, Eastern Sporades, the Cyclades, and Crete. We recommend an increase in environmental education and communication among older and younger generations, agriculturalists, politicians, policy writers, land developers and economists to create an understanding for the need to protect land and aquatic environments that harbor unique species and the potential benefits for economic activities such as ecotourism. We also recommend the creation of an action plan to develop ecotourism around conservation areas ( e.g. from the source of existing springs downstream for about 200 m before the installation of water withdrawal equipment for irrigation and potable supplies) to generate revenue for funding protection initiatives and to promote green economic development that is ecologically and socio-culturally sustainable.