Ecological and Evolutionary Significance of Nutritional Flexibility in Planktotrophic Larvae of the Deep Sea Red Crab Geryon quinquedens and the Stone Crab (Menippe mercenaria)

Abstract

Larvae of crab species inhabiting the shallow water marine environment show a wide range in nutritional requirements that must be satisfied via the diet. The present study compares the dietary requirements of larvae of the deep sea red crab Geryon quinquedens Smith with those of the stone crab Menjppe mercenaria Say, a shallow water species. Stone crab larvae cannot survive to metamorphosis on a rotifer diet. Red crab larvae show no difference in survival to metamorphosis on rotifer and brine shrimp nauplius diets, although some delay in development is seen on the former diet. We speculate that increased nutritional flexibility exhibited by the red crab is related to its deep water habitat and that evolution of such flexibility may be required for penetration of that habitat.