Habitat selection in the tropical polychaeteSpirobranchus giganteus

Abstract

Spirobranchus giganteus (Pallas) is an obligate associate of live coral. Its distribution on corals was studied at three locations along the bank reef on the west coast of Barbados in 1986. The degree of colonisation by worms (no./surface area of coral) differed between coral species. This implies differences in larval preference at settlement and/or differences in mortality following settlement. The degree of colonisation was not correlated with total surface area nor mean coral colony size, nor with the rank of the coral in an aggression hierarchy.Diploria strigosa, Porites astreoides andMillepora complanata were most heavily colonised.Montastrea annularis, Madracis spp. andAgaricia spp. were moderately colonised andPorites porites, Diploria labyrinthiformes, Montastrea cavernosa andSiderastrea siderea were sparsely colonised.Colpophyllia natans, Dendrogyra cylindricus, Dichocoenia stokesii, Eusmilia fastigata, Meandrina meandrites andMycetophyillia spp. were not colonised. Worm abundance differed between study sites, possibly reflecting a difference in larval availability at the three sites. Worms were significantly clustered at all sites, suggesting an attraction for conspecifics at settlement.