DAILY VARIATIONS OF OXYGEN-CONSUMPTION AND GLUCOSE HEMOLYMPH LEVEL RELATED TO MORPHOPHYSIOLOGICAL AND ECOLOGICAL ADAPTATIONS OF CRUSTACEA

Abstract

1. Daily variations of oxygen consumption and glucose hemolymph level of seven crustacean species from the continental shelf of the NW Gulf of Mexico were related to the morphophysiological (exoskeleton thickness) and ecological (activity rhythms) adaptations. 2. Metabolic rate and the hemolymph glucose changed with the daily activity patterns observed in the shrimps (Penaeus aztecus: nocturnal

Sicyonia brevirostris: diurnal), the portunid crabs (Callinectes similis, Portunus spinicarpus and P. gibbesii

nocturnal) and the calappids (Calappa sulcata

diurnal

Hepatus ephelyticus: non-selective activity pattern). 3. Rates of oxygen consumption versus glucose concentration were greater in shrimps than in portunids and calappids, and were related to exoskeleton thickness and activity rate. The glucose concentration was considered as the main energy source for the crustacean muscle. 4. Proportion of glucose concentration in relation to oxygen consumption (100%) varies among species, with lowest values for shrimps (55%), against the values recorded in portunid (126%) and calappid crabs (235-423%), indicating the amount of glucose required for chitin synthesis of species with different morphophysiological designs and activity patterns.