title: DNA Barcoding Reveals High Cryptic Diversity of the Freshwater Halfbeak Genus Hemirhamphodon from Sundaland.
abstract: DNA barcoding of the cytochrome oxidase subunit I (COI) gene was utilized to assess the species diversity of the freshwater halfbeak genus Hemirhamphodon. A total of 201 individuals from 46 locations in Peninsular Malaysia, north Borneo (Sarawak) and Sumatra were successfully amplified for 616 base pairs of the COI gene revealing 231 variable and 213 parsimony informative sites. COI gene trees showed that most recognized species form monophyletic clades with high bootstrap support. Pairwise within species comparisons exhibited a wide range of intraspecific diversity from 0.0% to 14.8%, suggesting presence of cryptic diversity. This finding was further supported by barcode gap analysis, ABGD and the constructed COI gene trees. In particular, H. pogonognathus from Kelantan (northeast Peninsular Malaysia) diverged from the other H. pogonognathus groups with distances ranging from 7.8 to 11.8%, exceeding the nearest neighbor taxon. High intraspecific diversity was also observed in H. byssus and H. kuekanthali, but of a lower magnitude. This study also provides insights into endemism and phylogeographic structuring, and limited support for the Paleo-drainage divergence hypothesis as a driver of speciation in the genus Hemirhamphodon.
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia.|School of Biological Sciences, Faculty of Integrative Sciences and Technology, Quest International University Perak, Ipoh, Perak, Malaysia.
authors.forename: HongChiun
authors.initials: H
authors.lastname: Lim
authors.affiliation: Department of Aquaculture, Faculty of Marine and Fisheries, Syiah Kuala University, Banda Aceh, Indonesia.
authors.forename: Muchlisin
authors.initials: M
authors.lastname: Zainal Abidin
authors.affiliation: Department of Aquatic Resources Management, Faculty of Fisheries and Marine Science, Riau University, Pekanbaru, Indonesia.
authors.forename: Chaidir Parlindungan
authors.initials: CP
authors.lastname: Pulungan
authors.affiliation: School of Biological Sciences, Bangor University, Bangor, United Kingdom.|School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia.
authors.forename: Mark
authors.initials: M
authors.lastname: de Bruyn
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia.|Centre for Marine and Coastal Studies, Universiti Sains Malaysia, Penang, Malaysia.
authors.forename: Siti Azizah
authors.initials: SA
authors.lastname: Mohd Nor