Taxonomic revision of the Southeast Asian brook barb genus Poropuntius Smith, 1931 (Teleostei, Cyprinidae) with description of a new species from Vietnam.

Molecular data from samples encompassing 22 nominal species of Poropuntius indicate that the species-level diversity in the genus has been vastly overestimated, likely due to inadequate taxon and geographic sampling and reliance on morphological characters that vary intra-specifically. The latter includes discrete mouth morphologies related to alternate feeding strategies (ecomorphs) within populations. One new species is described, Poropuntiusanlaoensis Hoàng, Phạm & Trần, sp. nov. , and 17 synonyms of six valid species names of Poropuntius , P.krempfi , P.alloiopleurus , P.huangchuchieni , P.laoensis , P.kontumensis , and P.deauratus , are recognised. Additional taxonomic changes in this widespread and generally poorly known genus are likely as more molecular and morphological data become available.