Mapping taxonomic knowledge and barcoding progress: An integrative review of marine fish species described from Malaysian waters

Abstract

Abstract This study presents the first systematic review of 118 nominal species of marine fish formally described from Malaysian waters between 1830 and 2025, spanning 22 orders and 53 families. Distinct temporal phases in taxonomic activity were identified: the pre-2000 era dominated by colonial-era expeditions yielded 94 species, with Cantor's 1849 Penang survey contributing 34 species. The post-2000 era represents a fundamental restructuring, with Malaysian-associated ichthyologists now active in species descriptions, establishing local repositories and adopting modern designation practices. Bibliometric analysis shows authorship remains concentrated among core contributors, with growing local taxonomic capacity. DNA barcoding of 63 morphospecies revealed substantial cryptic diversity, with RESL and GMYC delimitation identifying 131 and 134 molecular operational taxonomic units (MOTUs), respectively. A total of 27 species comprised multiple MOTUs, with nine priority taxa exhibiting cryptic complexity including Otolithes ruber, Glossogobius giuris, Uranoscopus cognatus, Taeniamia fucata, Pisodonophis cancrivorus and commercially important species such as Sardinella albella, Ilisha elongata, Cynoglossus arel and Lethrinus lentjan requiring integrative taxonomic revision. This study establishes a framework for biodiversity research, identifies gaps in molecular representation and demonstrates the value of integrating historical taxonomy with molecular approaches in one of the world's most species-rich marine regions.