POMACENTRID POPULATION-DYNAMICS ON SINGAPORE CORAL-REEFS

Spatial distribution of the pomacentrids on Singapore reefs was assess ed visually, while temporal change was studied within permanent quadra ts established on a patch reef between 4 Jul and 30 Nov 1989. Partitio ning of space, both horizontally and vertically, on the reef was obser ved in 15 species. The population of territorial damselfishes on the r eef flat was less stable than on the reef slope over time, due to the seasonal occurrence of dense stands of the brown macroalgae, Sargassum . Space was found to be a limiting factor at the reef flat due to the high density of pomacentrids found there. Food resource was the limiti ng factor on the reef slope, where low light intensity due to sediment ation and lack of suitable substrate inhibited turfalgal growth. Multi -specific recruitment of juveniles occurred in April and between mid-O ctober and early November.