Influence of Fish Predators on the Distribution and Abundance of 'Diadema antillarum'

摘要

Grazing by sea urchins has been demonstrated to affect the productivity and diversity of both temperate and tropical communities through reduction of available prey biomass. Overgrazing occurs when the local density of urchins is increased either through natural causes or by experimental manipulations. To accurately predict the potential impact of changes in urchin densities on community structure, it is necessary to understand the mechanisms which act on or within urchin populations to control or limit urchin distribution and abundance. Predation is one mechanism whereby urchin abundance may be regulated and temporal-spatial distributions (activity patterns) maintained. Several predators on Diadema antillarum, the long spined urchin, have been identified and include at least 18 fish, two gastropod, and two decapod species.