Daily ration estimates and comparative study of food consumption in nine species of deep-water decapod crustaceans of the NW Mediterranean

Estimates of the daily ration consumed by 9 species of decapod crustaceans were obtained from 2 deep-water samplings over the middle and lower continental slope of the NW Mediterranean. The daily rations obtained varied by an order of magnitude from the slow-moving, crab-like species (<0.1 g dry food per 100 g predator body weight) to the actively swimming mesopelagic shrimps (> 1.0 g dry food per 100 g predator body weight). A multivariate analysis allowed us to relate the variability in daily ration estimates to the functional morphology and ecology of the species considered. The functional morphology and ecology of the species studied are defined in terms of body shape, swimming capability, trophic diversity and spatial distribution. We found that body shape (ratio of carapace length to carapace width) and trophic diversity (H') account for most of the variability in the amount of food consumed by decapods. The food consumption pattern established for our decapod crustaceans is compared to a similar pattern reported for deep-water fishes.