Similarity in the feeding ecology of parrotfish (Scaridae) in coral reef habitats of the Malaysian South China Sea, as revealed by fatty acid signatures

•Fatty acid composition and levels were examined in coral fishes.•Proportions of saturated fatty acids were the highest proportions.•Polyunsaturated fatty acids increased with fish growth.•Diet shifts were revealed by the fatty acid composition.

To understand the trophic ecology and habitat use of coral reef fish, the fatty acid composition and levels were examined in three species of parrotfish, Scarus psittacus: Scarus quoyi and Scarus rivulatus, which were collected at the Bidong Island of the Malaysian South China Sea. The proportions of saturated fatty acids (SAFA) are 57.6–64.9%, where fatty acids have the highest proportion, monounsaturated fatty acids (MUFA) (25.3–25.9%) have the second highest proportion, and polyunsaturated fatty acids (PUFA) (9.2–17.1%) have the lowest proportion. Palmitic acid (C16:0) is the most common acid in SAFA, palmitoleic acid (C16:1) is the dominant acid in MUFA, and eicosatrienoic acid (C20:3n3) and eicosapentaenoic acid (EPA, C20:5n3) have the highest proportions in PUFA. The composition of each fatty acid does not differ among species, which suggests that the feeding ecology and habitat use of the fish in the coral reef ecosystem are similar. The fatty acid concentrations, particularly that of PUFA, increase with the fish growth, which suggests that the diet and habitat shift during the life history of the fish. The diet shifts revealed by the fatty acid composition and levels suggest the similarity in habitat use and feeding ecology of those types of parrotfish.