AN UPDATE ON THE DIVERSITY OF FRESHWATER FISHES OF PENINSULAR MALAYSIA

Peninsular Malaysia is a vital component of the Sundaland biodiversity hotspot, harboring a significantly rich and complex freshwater fish fauna. Recent ichthyological surveys and taxonomic revisions continue to refine our understanding of this diversity, which is estimated to include over 300 native species. The family Cyprinidae (carps and minnows) consistently dominates the species count, a pattern observed across major river systems like the Pahang River, which alone boasts a substantial list of species. Current updates frequently involve resolving taxonomic ambiguities through molecular and morphological studies, clarifying the identities of species within complex groups and often resulting in new species descriptions or new records for a specific locality. For instance, studies in areas like the Tasik Bera have recently documented new records, highlighting that the true extent of species richness, even in relatively well-studied areas, is still being uncovered. Despite this richness, the freshwater fish community faces escalating threats. Habitat degradation from development, deforestation, agricultural runoff, and water pollution are key stressors. Alarmingly, the presence and spread of non-native (alien) fish species, often introduced for aquaculture or the aquarium trade is a major concern. These introduced species, such as various Redtail catfish, Tilapia and Suckermouth catfish, threaten to disrupt the delicate balance of native aquatic ecosystems through competition and predation. Furthermore, a significant number of native species are categorized under threatened conservation statuses (Vulnerable, Endangered, or Critically Endangered), emphasising the urgent need for concerted conservation efforts. Future research must integrate field surveys, molecular analyses, and a focus on endemic or at-risk species to ensure the preservation of Peninsular Malaysia’s extraordinary freshwater fish heritage.
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ASSOC. PROF. DR. AMIRRUDIN AHMAD

Institute of Tropical Biodiversity and Sustainable Development, Universiti Malaysia Terengganu

Associate Professor Dr. Amirrudin Ahmad’s research is mainly focus on measuring biodiversity of a diverse groups of fauna in Peninsular Malaysia. His interest including ecology of aquatic and terrestrial animals, and taxonomy and systematics of various groups of fauna, especially the freshwater fishes. His current research focuses on the inland waters and terrestrial ecosystems aim to documenting the diversity of fishes, amphibians, and reptiles in the Terengganu River basin, and Peninsular Malaysia as well as studying the insular fauna of the South China Sea, in general. He has authored and co-authored several scientific papers and involved in describing several animals in the recent years. He has more than 20 years of teaching and research experiences and has supervised postgraduate and undergraduate students. He is currently the Director at the Institute of Tropical Biodiversity and Sustainable Development, UMT and also a Regional Co-chair for the Mainland and Peninsular Southeast Asia region for IUCN SSC/WI Freshwater Fish Specialist Group.