Interspecific competition in Taiwanese corals with special reference to interactions between alcyonaceans and scleractinians

Naturally occurring interspecific competition in scleractinian and alcyonacean corals was studied on the reefs of southern Taiwan. A total of 1168 pairwise interactions were recorded and analysis of the data, using a competitive index, led to classification of corals into 5 categories. Three major conclusions can be drawn. (1) The ranlung of competitive ability shown by a species bears little apparent relationship to its systematic position, and the most aggressive corals such as Merulina ampliata, Echnophyllia asper, and Myceaium elephantotus are often most abundant on the reefs. (2) Alcyonaceans are generally subordinate when in contact with scleractinians; the former are often subjected to mesenterial digestion by the latter. The position of contact is probably an important determinant in interactions between soft and hard corals. (3) Coral interspecific interactions on the reefs of southern Taiwan show some evidence of competitive networks.