Reef structure drives parrotfish species composition on shelf edge reefs in La Parguera, Puerto Rico

Shelf edge reefs that exist in coral reef ecosystems provide essential habitats for a large variety of fish and other marine organisms. Marine herbivores act as differential algal grazers that advocate coral reef colonization. In the Caribbean basin parrotfishes make up a large contingency of such herbivores and act as important ecological ichthyofauna. By investigating parrotfish relationship with habitat, this study aims to aid in future predictive mapping techniques that will outline parrotfish distributions via benthic quantification. Parrotfish communities were evaluated on the shelf edge reef off of La Parguera, Puerto Rico. Parrotfish abundances were found to positively correlate with high values of overall reef structure. High values of coral cover and of rugosity were strong indicators of most parrotfish species. The lone exception, Scarus taeniopterus, negatively correlated with these factors and positively correlated with algal cover. Indications exist that Scarus taeniopterus and Scarus iseri are sympatric species and can be found in abundance at opposite locations. ► Benthic habitat structure drives scarid community dynamics at shelf edge reefs. ► Scarids are positively associated with rugosity and high coral cover. ► Scarus taeniopterus exhibits spatial patterns that contrast with other parrotfishes. ► Niche specialization seems to exist between Scarus taeniopterus and Scarus iseri.