Abstract
The taxonomy of the family Mugilidae has historically posed challenges, marked by discrepancies between described and valid species, compounded by cryptic diversity and a similar external appearance. Previous studies left four of six lineages unidentified within Crenimugil, including Crenimugil sp. A and Crenimugil sp. B. The goal of this study is to provide a detailed revision of species assigned to Crenimugil by examining specimens from the Red Sea, which is the type locality of Mugil crenilabis, Mugil seheli and Mugil tade, which were here genetically analyzed. After demonstrating that the genus contains nine monophyletic lineages and Moolgarda pura is a valid nominal species, the mugilid genus Moolgarda is restored. Consequently, Moolgarda has priority over Crenimugil and Valamugil. Additional morphological analyses of specimens from the Red Sea assigned to Moolgarda sp. A and Moolgarda sp. B identified them as representing Moolgarda seheli and Moolgarda crenilabis, respectively. A phylogenetic analysis, including new DNA barcodes, confirmed a wide distribution range of both species in the Indo-West Pacific. The identity of the lineage previously identified as Crenimugil crenilabis remains doubtful, and it is referred to as Moolgarda cf. crenilabis here. A third lineage, previously named Crenimugil buchanani, is re-described as Moolgarda tade, a species originally reported from the Red Sea with a long history of taxonomic confusion. The species is widely distributed in the Indo-West Pacific and distinguished from other congeners by falcate second dorsal and anal fins that are distinctly higher than the first dorsal fin. A detailed description of the Red Sea specimens of M. crenilabis, M. seheli and M. tade is provided, with comments to other unnamed lineages.