Relevant Synonyms - Misidentification -  photo: Carlo Froglia

SHORT DESCRIPTION Carapace subhexagonal, surface minutely granular. Front divided by median notch, in two sinuate lobes. Antero-lateral margin with post-orbital tooth followed by a sinuate lobe and three pointed teeth. Chelipeds massive, unequal, especially in large males. Merus with a subdistal stout tooth on upper margin. Carpus with acute tooth on inner distal margin. Palm smooth (in females two ill-defined longitudinal crests on dorsal surface). Male first gonopod with tip strongly deflexed laterally. color : carapace and chelipeds dark olive green to brown, with smaller darker speckles. Chela with black fingers. common size : males up to 2.5 cm CL, females 1.5 cm CL. DISTINGUISHING CHARACTERISTICS Carcinus aestuarii: cheliped fingers not black; trilobate front; five antero-lateral teeth. Other Mediterranean xanthoids: black fingers and either granulate carapace or five well separated antero-lateral teeth. BIOLOGY / ECOLOGY Breeding in late summer; egg-bearing females from 1.0 cm CL. Egg diameter 0.3 mm. Feeds mostly on juvenile bivalves and Balanus spp. habitat : in the Northern Adriatic mainly found in shallow brackish waters on soft bottoms with sparse stones and mussel beds.

1st MEDITERRANEAN RECORD Italy, Northern Adriatic Sea, 1993 [1992]. DISTRIBUTION Worldwide : North-West Atlantic. Recorded on the English coast, Bristol Channel. Mediterranean : recorded first from Italy, Venice lagoon (Froglia and Speranza, 1993 [1992]). Successively found in the Marano lagoon, 70 km east of Venice (Froglia pers. comm., 1997), and along the Romagna coast (Fabbri and Landi, 1999). The species is spreading southward in the Western Adriatic, an ovigerous female was collected off Cattolica in 2004 (specimen deposited in C. Froglia collection, Ancona). ESTABLISHMENT SUCCESS Very abundant in the Venice lagoon, locally may outnumber the autochthonous crabs Carcinus aestuarii and Pilumnus spp. speculated reasons for success : - MODE OF INTRODUCTION Ballast transport, or unintentionally imported with clam seed. IMPORTANCE TO HUMANS Feeding on bivalves, may affect local clam farming.

KEY REFERENCES Froglia C. and S. Speranza, 1993. First record of Dyspanopeus sayi (Smith, 1869) in the Mediterranean Sea (Crustacea: Decapoda: Xanthidae). Quaderni dell' Istituto di Ricerche sulla Pesca marittima, 5(2): 163-166. Ingle R., 1980. British Crabs. Oxford University Press. 222 pp. Martin J.W. and L.G. Abele, 1986. Notes on male pleopod morphology in the brachyuran crab family Panopeidae Ortmann, 1893, sensu Guinot (1978) (Decapoda). Crustaceana, 50(2): 182-198.   Williams A.B., 1984. Shrimps, lobsters, and crabs of the Atlantic coast of the Eastern United States, Maine to Florida. Smithsonian Institution Press. 550 pp. FEEDBACK / COMMENTS TO AUTHORS

Last update of the species sheet: February 2005 ©ciesm 2002