Morphometric and genetic variations of three grouper species (genus Epinephelus) from the northern region of Aceh province, Indonesia

Groupers are a commercial group of reef fish found worldwide in the warmer waters, including Indonesia. Epinephelus is one of the dominant genus in the Indonesian waters of the Aceh province waters, where three species Epinephelus areolatus, Ephinephelus fasciatus, and Ephinephelus merra are frequently caught by fishermen in the northern region. However, information on the morphological and genetic variations of the species are limited. Therefore, the objective of the present study was to document morphological and genetic variations of the species in addition to validate their taxonomic and kinship status. The specimens were collected from June to December 2020 at Lampulo fishing port Banda Aceh, Aceh, Indonesia. A total of 180 Epinephelus samples representing 60 samples of each species were used for the morphometric analysis. Of these, ten individuals were randomly taken for DNA analysis based on the Cytochrome c oxidase I (COI) gene. One-way ANOVA and Discriminant Function Analysis (DFA) were performed to distinguish morphometric variations among species. Morphological analysis displayed that E. fasciatus and E. merra had high similarities, while E. areolatus was distinguished from others. The genetic analysis showed grouper samples were differentiated into three species namely of E. fasciatus, E. merra and E. areolatus. The closest genetic distance was between E. fasciatus and E. merra (12.81%), while the farthest genetic distance was between E. areolatus and E. merra (16.05%). The two methods used in this study can be used to validate the taxonomic status of a species.