Interactions between ophiuroids and beaugregory damselfish

Abstract

The interactions between beaugregory damselfish and ophiuroids, potential damselfish egg predators, were investigated using several field studies. A survey of back reef areas showed that the two most common ophiuroid species, Ophiocoma echinata and Ophioderma appressum, were significantly associated with the territories of beaugregory males within the coral rubble habitat where both ophiuroids and beaugregory's can be found. Feeding experiments showed that three ophiuroid species (Ophiocoma echinata, Ophioderma appressum and Ophiocoma wendtii) and Echinometra viridis consumed late development stage beaugregory eggs, whereas earlier stages were only consumed by Ophioderma appressum and Echinometra viridis. Manipulation of ophiuroid densities had no significant effect on the survival of beaugregory eggs and had no measurable impact on female mate choice. The aggressive response of male beaugregory damselfish towards three ophiuroid and one echinoid species showed significant differences among species but were lower than those shown to bluehead wrasse, Thallasoma bifasciatum; the principal daylight predator of eggs. The intensity of attacks by male beaugregory damselfish towards Thallasoma bifasciatum increased significantly if males were guarding eggs, but did not appear to change for the four echinoderm species. Male habitat selection was shown to be unaffected by the presence of ophiuroids.