THE EUROPEAN GREEN CRAB Carcinus maenas POPULATION ON THE ATLANTIC COAST OF PATAGONIA: LATITUDINAL DISTRIBUTION, PATTERN OF ABUNDANCE, SIZE AND SEX STRUCTURE, HABITAT USE, INTERACTION WITH NATIVE SPECIES AND INFESTATION BY PARASITES

BARÓN, P.J.; LEAL, G.A.; HIDALGO, F.J.; DELLATORRE, F.G.; GAVIO, M.A.; PACOTTI, V.; RAPOSO, P.; BAZTERRICA, M.C.; LEDESMA, F.M.; BERTNESS, M.

La Serena, Chile

Congreso; The Crustacean Society Mid-Year Meeting; 2007

The Crustacean Society

Since the discovery and first report on the invasion of Carcinus maenas to the Eastern Patagonian coast by Hidalgo, Barón & Orensanz in 2005, a study was conducted to evaluate the characteristics of the non-native population and its possible interactions with the native community. To determine the physical and biological characteristics of the habitats occupied by C. maenas, live specimens were sampled monthly in Carolina Inlet (44°54’S - 65°36’W) by manual collection and trapping on the intertidal and SCUBA diving on the subtidal and dead specimens were taken on 3-m wide transects along the wrack from January 2004 to June 2007. Also, four surveys were completed along the Atlantic coast of Patagonia to establish the latitudinal distribution, patterns of abundance and habitat use of the species. Biological parameters (size, sex, maturity stage, moulting stage, mating condition and presence of parasites) were registered in the lab and preliminary predation experiments were performed in aquaria. Data obtained shows that C. maenas is distributed from Camarones bay (44°48’S) to Puerto Deseado estuary (47°46’S), from the upper intertidal to the shallow subtidal (up to 2 m deep). Highest abundance (up to  4 crabs trap-1 h-1 and 0.9 individuals m-1 in transects along the wrack) occur in the southern coast of San Jorge Gulf. The crab inhabits protected (e.g. Carolina inlet) to very exposed (e.g. Del Marquez Point and Cape Blanco) segments of the coast, being exclusively associated to structured hard bottoms. Shelters include rock crevices and the undersides of stones and Corallina mats growing in tidal pools. Two types of internal parasite were found in the species. Size structure shows differences between sampling areas, a wider size range being represented in samples from the South of San Jorge Gulf. C. maenas preys on a variety of native gastropods, bivalves, polychaetes and crabs.