Reef Corals: Mutualistic Symbioses Adapted to Nutrient-Poor Environments

Abstract

Coral atoll communities are of special interest to marine biologists since they flourish in tropical waters characterized by low productivity (cf. Stoddart 1969). One of the aims of research in coral reef biology is to discern and describe quantitatively the adaptations that permit reef communities to exploit a marginally suitable habitat. Vital to this aim is an understanding of the nutrition of corals themselves since these lime-secreting cnidarians are the dominant life forms of many reefs and one of the principal reef builders. The general topic of coral nutrition has been reviewed recently (Muscatine 1973, Taylor 1973a) and serves as a convenient point of departure. The present discussion considers the potential nutritional capabilities of corals as mutualistic symbioses and the extent to which specific organismic and ecological manifestations of these capabilities have been described and quantified.