Reef Zoobenthos

Abstract

The bottom fauna of coral reefs is extremely rich and varied. It finds there good trophic conditions, plenty of hiding places to escape grasing for vagile animals and a great abundance of solid substratum for sessile benthic invertebrates (Paine 1974; Kohn and Levitien 1976; Reichelt 1982). A sample of 2–3 kg of the rock material may contain over 100 species of animals from several tens of families (Hutchings 1974). Main groups of reef zoobenthos could be represented on a separate reef by hundreds of species: 50–150 species of forams, 150–500 species of molluscs, 100–250 species of crustaceans, 50–100 species of echinoderms, 100–200 species of polychaetes, and 50 and more species of sponges. This high species diversity of benthic animals has its origin in their fine trophic and ecological partitioning and specializations, and in a wide distribution among them of commensalism, symbiosis, different morphological adaptations, chemical and color information, and chemical defence. The macrobenthos is probably one of the best-studied components of reef fauna from the chorological aspect. The meio- and the microbenthos have been much less studied, which is explained by the methodological obstacles of sampling in rocky substrata of the reef (Hutchings 1974). The same is the cause of deficiency in the quantifications of the biomass of reef benthos, and especially of its meyo- and microcomponents.