Review of the spotted lizard loaches, Pseudohomaloptera (Cypriniformes: Balitoridae) with a re-description of Pseudohomaloptera sexmaculata and description of a new species from Sumatra.

A review of the six recognized species of Pseudohomaloptera is provided. Counts in the original description of Pseudohomaloptera sexmaculata Fowler (1934) were incorrect and led to confusion in identifying populations of Pseudohomaloptera in mainland Southeast Asia, and the species is re-described. The validity of Homaloptera septemmaculata Fowler (1934) is investigated and confirmed as a junior synonym of P. sexmaculata. P. sexmaculata and Pseudohomaloptera leonardi, similar morphologically and often misidentified, are widely distributed in mainland Southeast Asia, with P. sexmaculata in the Chao Phraya, Mae Klong and Pran Buri River basins, and P. leonardi in the Malay Peninsula and the Chao Phraya and Mekong River basins. Pseudohomaloptera yunnanensis and Pseudohomaloptera vulgaris have been reported from the Mekong basin of Thailand and Laos but appear to be restricted to Yunnan Province, China. A new species of Pseudohomaloptera is described from Sumatra. This is the southern-most species and first record for the genus from the Indonesian island. An identification key is provided for all species of the genus.