Defenses of Caribbean sponges against predatory reef fish. I. Chemical deterrency

Abstract

Laboratory feeding assays employing the common Caribbean wrasse Thalassoma bifasciatum were undertaken to determine the palatability of food pellets containing natural concentrations of crude organic extracts of 71 species of Caribbean demosponges from reef, mangrove, and grassbed habitats. The majority of sponge species yielded deterrent extracts, but there was considerable inter- and intraspecific variability in deterrency. Reef sponges generally yielded more deterrent extracts than sponges from mangrove or grassbed habitats, but 4 of the 10 most common sponges on reefs yielded palatable extracts. There was no relationship between sponge color and deterrency. There was also no relationship between the toxicity of sponge extracts and deterrency. -from Authors