Ségrégation édaphique et bathymétrique chez le crabe des neiges, Chionoecetes opilio (O. Fabr.), dans le sud-ouest du golfe du Saint-Laurent

Abstract

A population of Chionoecetes opilio was studied during the summers of 1980 and 1981 in the southwestern Gulf of St. Lawrence, at the entrance of the Bay of Chaleur, and the Gaspé Bay. Sampling was conducted with beam trawls and baited traps at depths ranging from 45 to 125 m. Crab shell width of both sexes was measured and physiological maturity determined according to a biometrical index. Immature individuals of both sexes are essentially localized on the upper bathymetrical levels, on gravelly mud, whereas adults are found mainly on mud or sandy mud bottoms. We hypothesize that young crabs move down to the muddy bottom where recruitment to the fishery occurs. This deplacement seems to be concomitant with physiological maturity.