Biology of Brazilian Benthic Reef Builders and Dwellers

Brazilian reef environments are composed of a unique fauna. This chapter addresses the general biological and ecological aspects of 12 benthic reef-dwelling taxa found in Brazil: (i) scleractinian corals, which are primary reef-builders that produce the tridimensional framework; (ii) calcified hydrozoans belonging to the Millepora genus; (iii) other cnidarians such as octocorals, zoanthids and anemones; (iv) crustose coralline algae, which are also major reef-builders that produce extensive rhodolith beds; (v) bryozoans and (vi) vermetid gastropods, which have contributed significantly to reef-building in the Abrolhos Bank and Rocas Atoll, respectively; (vii) echinoderms, with emphasis on sea urchins, that control algal overgrowth through herbivory but may also contribute to bioerosion; (viii) sponges, which are abundant in Brazilian reefs and both add structural complexity and recycle organic matter, but also contribute to reef erosion; (ix) polychaetes and (x) mollusks, both of which may occasionally contribute to reef accretion and also engage in burrowing and erosion; (xi) crustaceans, which interact with numerous taxa and form multiple trophic links; and (xii) ascidians, a diverse cryptic dweller of the reef matrix. The basic morphology is presented for each taxon, as well as their diversity, reproductive biology and main functional roles.