The Role of Sponge Collagens in the Diet of the Hawksbill Turtle (Eretmochelys Imbricata)

Abstract

Sponges are an important component of many hard-substrate marine communities. This is particularly true on coral reefs, where the contribution of sponges to the reef biomass frequently exceeds that of hermatypic corals1. Despite their widespread distribution and abundance, however, sponges have few significant predators2. Certain species of dorid nudibranch mollusks, echinoid and asteroid echinoderms, and fish are notable exceptions. This relative immunity to predation has been variously attributed to the mechanical protection provided by skeletal components such as siliceous spicules and tough, organic fibers, and to the chemical protection provided by toxic or noxious secondary compounds3,4 The defensive utility of these attributes of sponges against potential predators, however, remains largely inferential.