The comparative study on the osteocranium of red snappers Lutjanus malabaricus (Schneider, 1801) and Lutjanus timorensis (Quoy & Gaimard, 1824) harvested from Pulo Aceh Waters, Indonesia

Abstract

Red snapper fish is one of the most economically important marine fish groups in the world with high morphological similarities. Currently, the taxonomy of snappers relies on external morphological characteristics and genetics (DNA barcoding). Relying solely on morphology for taxonomy might lead to invalid results, whereas the genetic approach is known to be costly and time-consuming. Therefore, this study aims to examine the difference in the head bone (Osteocranium) osteology of two red snappers species namely Lutjanus malabaricus and L. timorensis, harvested from Aceh waters, Indonesia using an alternative approach based on osteological characteristics. A total of five fish samples of each species were collected from fishermen operating in the northern waters of Aceh and were landed at the Lampulo Fish Port, Banda Aceh City, Indonesia. Osteology samples were prepared through six steps, including exterior muscle elimination, immersion in 70% alcohol solution, drying, photographing bones, image editing, and identification of terminology. The results showed that the cranial of Lutjanus is supported by 25 bones, where 13 bones showed differences among the two species of red snappers, namely the nasal, preethmoidal, ethmoidal lateralis, prefrontal, foramen frontal, pterotic, lacrimal, crista occipital, interopercular, opercular, palatinum, preopercular, and premaxilla bones. Among these, a significant difference was found in the angle of the crista occipital bone, where L. timorensis was higher than L. malabaricus. Therefore, it was concluded that the crista occipital bone was a key characteristic to distinguish between the two species of red snappers examined. This study showed that the osteocranium approach can be employed to validate the taxonomic status of these species.