Taxonomic validation of Areolate grouper, Epinephelus areolatus (Perciformes: Serranidae) along the Nizampatnam coast, India

ABSTRACT

Groupers (Perciformes Serranidae Epinephelinae) are a significant group of marine and estuarine fishes havingecological and commercial importance in tropical and subtropical waters. The genus Epinephelus is identifiedbased on the color configuration and morphological characteristics. The homogeneity in the morphologicalcharacteristics has created confusion in the species identification of Epinephelus. Epinephelus areolatus withits delicious taste has high economic value; however, its population showed a remarkable decline in recenttimes due to overfishing. Due to morphological resemblance, it has often been confused with Epinepheluschlorostigma and Epinephelus bleekeri, which leads to misidentification. Hence, correct identification ofspecies is needed for the proper management of fish resources. This study aims to identify and validate E.areolatus by using morpho-meristic characteristics, including the number and pattern of pyloric caeca, vertebraecount through radiograph imaging, scale and otolith morphology, and DNA barcoding. The morphologicaland meristic characteristics of Epinephelus species observed in Nizampatnam coast are strikingly comparableto those reported earlier as E. areolatus. Comparative molecular analysis was also carried along with othermorphologically similar species, viz. E. chlorostigma and E. bleekeri, using mitochondrial cytochrome oxidaseI gene sequences. The mean interspecific genetic distance revealed high similarity with E. bleekeri (0.109 ±0.012) and low similarity with E. chlorostigma (0.079 ± 0.009). The neighbor-joining tree has shown distinctclades for three species with high bootstrap values. The partial DNA sequence of the mitochondrial cytochromeoxidase I was established for the first time for E. areolatus from the Nizampatnam coast in this study