Jean-Claude F. Brêthes

Aspects De L'Alimentation Et Du Comportement Alimentaire Du Crabe-Des-Neiges, Chionoecetes Opilio (O. Fabr.) Dans Le Sud-Ouest Du Golfe De St-Laurent (Decapoda, Brachyura)

The stomachs of 480 specimens of the snow-crab, Chionoecetes opilio, from the entrance of the Chaleur Bay were collected in May 1980. 418 contained the remains of at least one prey. Snow-crabs feed mostly in the middle of the night but feeding activity seems possible during day time. The estimated daily ration is about 0.4% of the live weight. Crustacea occupied on the average 34% , in number, of the stomach content, Mollusca 21% , Echinodermata 17 % and Polychaeta 12% . The frequency with which these preys occurred was 64% for Crustacea, 32 % for Echinodermata, 31 % for Mollusca and 23% for Polychaeta. This overall pattern depended on the depth of sampling. Above 90 m, Crustacea occurred most frequently followed by Mollusca and Echinodermata; below 110 m, the order was changed to Echinodermata, Crustacea and Mollusca. Ivlevs electivity index was highest for Echinodermata at every depth but increased from shallow to deeper bottoms. Those observations indicate an opportunistic feeding behaviour on epifauna. A depth segregation observed between mature and immature males also suggest some change of diet during the life history of the snow-crab.