BIOTIC NEIGHBORHOODS OF SHALLOW- WATER GORGONIANS OF PUERTO RICO

摘要

Sessile organisms interact primarily with neighboring individuals. As a consequence, the taxonomic composition of "biotic neighborhoods" may provide insight into the organization of ecological communities as well as co-evolutionary relationships among species. In this study the biotic neighborhoods (defined by quadrat sizes of 1/64 m~2) of shallow-water gorgonians were examined at two sites in Puerto Rico. The composition of biotic neighborhoods of most taxa mirrored relative abundances in the entire 32 m~2 sample set. Exceptions to this overall pattern involved relatively higher occurrences of conspecific colonies for most taxa and lower occurrences of Pseudopterogorgia spp. with other taxa. Apart from these exceptions, biotic neighborhoods can be interpreted as random subsets of colonies from the local community. Because the identities of neighbors would be unpredictable for individual colonies, this result suggests that relationships between shallow-water gorgonian species are generalized rather than highly specialized (coevolved). This interpretation supports hypotheses advocating chance and ecological similarities as major determinants of the community structure of shallow-water gorgonians of the Caribbean.