A new species of Larimichthys from Terengganu, east coast of Peninsular Malaysia is described from specimens collected from the fish landing port at Pulau Kambing, Kuala Terengganu. Larimichthys terengganui can be readily distinguished from other species of the genus by having an equally short pair of ventral limbs at the end of the gas bladder appendages, which do not extend lateral-ventrally to the lower half of the body wall, and fewer dorsal soft rays (29-32 vs. 31-36) and vertebrae (24 vs. 25-28). Larimichthys terengganui can be distinguished from L. polyactis and L. crocea by having a gill raker at the angle of first gill arch shorter than the gill filament. Furthermore, the second anal spine in L. terengganui is equal or slightly shorter than eye diameter (vs. shorter in L. polyactis); L. terengganui has 8-9 anal soft rays (vs. only 7 in L. pamoides). Snout length of L. terengganui is greater than eye diameter, whereas in L. crocea the snout is shorter than eye diameter. A key to species of Larimichthys is provided. All obtained specimens of the species were recorded from Terengganu waters, east coast of Peninsular Malaysia.
In terms of sheer abundance, taxonomic diversity, and species richness, Malaysia has one of the most diverse Sciaenidae in the Indo-West Pacific. Up to ten valid species of the sciaenid fish genus Johnius (e.g., J. amblycephalus (Bleeker, 1855), J. belangerii (Cuvier, 1830), J. borneensis (Bleeker, 1850), J. carouna (Cuvier, 1830), J. coitor (Hamilton, 1822), J. heterolepis Bleeker, 1873, J. macrorhynus (Lal Mohan, 1976), J. plagiostoma (Bleeker, 1849), J. sasakii Hanafi et al., 2022 and J. weberi Hardenberg, 1936), and with additional newly recorded species as J. trewavasae Sasaki, 1992, have been recorded to occur in East Malaysia (Borneo Island) coastal waters. The newly recorded species is a close congener to J. heterolepis Sasaki, 1992 and can be well distinguished by several characters and molecular evidence. The goal of this study is to review the taxonomic status of Johnius species in East Malaysia, Borneo Island, by using a literature review, morphological inference and molecular characters. Principal Component Analysis (PCA) successfully discriminates based on second anal spine length and gill raker length within sampled specimens. A phylogenetic tree based on cytochrome oxidase subunit I (COI) showed intraspecific levels of genetic differentiation within Johnius of East Malaysia, which forms a monophyletic group. Moreover, the new record of Johnius trewavasae in East Malaysia represented that the distribution of the subtropical genus Johnius extended to the southernmost part of the tropical region.