Coral Predation by Sparisoma viride and Lack of Relationship with Coral Disease

Bruckner, A; Bruckner, R

A presumed new coral disease (rapid wasting disease; RWD), characterized by a rapid rate of tissue destruction and concurrent "dissolution" of the skeleton, is demonstrated here to result from predation by initial phase and terminal phase Sparisoma viride (stoplight parrotfish). These fish forage using beak-like jaws to scrape and excavate epililhic and endolithic algae from carbonate substrates, but they also bite live coral. Observations in Bonaire and Puerto Rico showed that S. viride most commonly created numerous small, shallow lesions (spot biting) that were within a coral's regeneration capabilities. They also created deep grazing scars that progressively radiated across colony surfaces through repeated, methodical biting (focused biting). Coral destruction occurred only during daylight, with no additional loss at night; lesions failed to increase in size when S. viride were excluded. Apparently healthy corals did not develop this condition when placed in direct contact with tissue and skeleton taken from lesions. In most cases, corals exhibited progressive regrowth of tissue over damaged skeleton. After 3 years, lesions have completely healed in Montastraea faveolata; in other species large lesions have failed to fully regenerate, but none have increased in the absence of continued predation. Additional studies are needed to determine whether focused biting is related to parrotfish abundance, territorial interactions, or other factors, and whether fish bites serve as a portal of entry for secondary pathogens.

Coral Predation by Sparisoma viride and Lack of Relationship with Coral Disease

Series