Paromola cuvieri (Risso), a Crab new to the Orkneys, Shetlands and Norway

Abstract

ON June 25, Prof. O. Nybelin brought me for identification some photographs of a large ‘spider’ crab, four specimens of which had been received by the Natural History Museum, Gothenburg, Sweden, between July 1955 and February 1956. The local fishermen, who had trawled the specimens at four separate localities off the Shetlands and Norway, recognized that they were quite new to fishing grounds with which their families had been familiar for generations. I was not altogether surprised to find that they belonged to a species first recorded from the Mediterranean, namely, Paromola cuvieri (Risso), since I knew of another unpublished recent record from the Orkneys. Prof. Nybelin informed me that they had also taken several Mediterranean species of fish in the same waters in recent months. Paromola, with a span of 3–4 ft. and a shell 6–8.5 in. long, is not a true spider-crab but a relative of the sponge-crab Dromia. It may be recognized by its club-like eyes set on slender stalks and the short last pair of legs, each ending in a curious subchela. It exhibits marked sexual dimorphism of the chelipeds which in the female are very slender and not much longer than the shell; in the male about three times as long as the shell and stouter than the walking legs. The Portuguese call it aranha do mar, Algerian fishermen diable because of its reddish colour and bizarre appearance.