Predation on elasmobranch eggs

Synopsis

Predation on large, energy rich eggs is common in terrestrial and freshwater communities with the eggs of amphibians, reptiles and birds figuring as prominant prey. We might predict that predation on large eggs would also be widespread in marine communities. However, little information is available to test this prediction. We present new evidence for such predation on elasmobranch eggs based on examination of capsules held in museum collections, those collected from beaches, long-term incubations of caged egg capsules, and SCUBA observation. The principal egg predators appear to be gastropods, though vertebrates contribute to mortality of embryonic elasmobranchs. As yet we can only speculate about the effects of egg predation for populations of oviparous elasmobranchs, or about the direct and indirect consequences predation upon their energy-rich eggs may have for marine communities.