Free-living corals: distributions according to plant cover, sediments, hydrodynamics, depth and biological factors

摘要: in 1974, 8 free-living coral species were found to inhabit the sandy sea floor adjacent Lizard Island, Great Barrier Reef (14°40′S; 145°78′E). They fall into two groups which colonize dissimilar sediment types. Plant cover increases with depth and, because of its effect on characteristics, is thought be a significant factor affecting distributions. The shallower coarse medium grain sediments (0.5 0.125 mm) are mainly colonized by Heteropsammia cochlea, Heterocyathus aequicostatus, Diaseris distorta, and lesser extent Cycloseris cyclolites. deeper made up biogenically derived fraction (larger than 0.5 combined an equally high proportion fine-grade material. Corals typically these are: Trachyphyllia geoffroyi, Catalaphyllia jardinei, Cynarina lacrymalis, patelliformis. content non-carbonate material reflects hydrodynamics area hence degree sedimentation, i.e., traction, saltation, or suspension loads, corals have cope with. Depth occurrence was predict local distributions but not applicable other regions. Other factors discussed relation include: mobility, shape, obligate sipunculan associate, Aspidosiphon jukesii, cochlea settlement requirements.