Review of the Predators and Parasites of Stony Corals, with Special Reference to Symbiotic Prosobranch Gastropods

Abstract

Predators and parasites on the living tissues of stony (scleractinian)
\ncorals include bony and cartilaginous fishes, asteroids, crustaceans (cyclopoid copepods,
\ncirripedes, and brachyuran crabs) , polychaetes, and gastropods (prosobranchs
\nand nudibranchs). These are all facultative predators except the crustaceans and
\ngastropods that are obligately associated (symbiotic) with and feed on their coral
\nhosts. Such symbionts are known in four unrelated families of crustaceans (Xarifiidae,
\nAsterocheridae, Balanidae, and Xanthidae) and four unr elated families of
\nprosobranch gastropods (Architectonicidae, Epitoniidae, Ovulidae, and Coralliophilidae)
\n. A fifth prosobranch family includes frequent but not obligate coral
\nassociates that are coral- and possibly also mollusk-feeders (Muricidae [Drupa,
\nsubgenus Drupella]). The eolid nudibranch genus Phestilla (Tergipedidae) includes
\nthe only so far identified opisthobranchs definitely symbiotic with corals.
\nMost of the crustacean and molluscan symbionts live with hermatypic corals in
\nthe Indo-Pacific. Specificity to particular genera or families of corals is low, but
\nthe bright yellow, orange, or pink phases (species?) of the dendrophylliid ahermatypic
\ncoral Tubastraea are host to similarly colored prosobranchs C Epitonitlm" )
\nand a nudibranch (Phestilla melanobrachia) . Adapt ations for feeding on coelenterates
\nare various, but in unrelated gastropod families similar specializations occur
\n(cuticularized esophaguses and proboscises, ptenoglossate-like radular teeth, and
\ntotal loss of radulae) . The most specialized of the coral-dwelling prosobranchs
\nare the coralliophilids ( including Magiltus), parasites without radulae living both
\non and in coelenterates.