Taxonomic revisions of Altigena laticeps and A. lippa (Cyprinidae: Labeoninae) from the Mekong River Basin.

ABSTRACT

Altigena laticeps, previously considered a junior synonym of A. lippa, is revalidated and re-described based on morphological examinations of type and non-type material. This species, found in the Upper Mekong River basin in China, can be distinguished from A. lippa based on higher numbers of lateral-line scales (40-42 vs. 34-39), predorsal scales (14-16 vs. 9-12), and circumpeduncular scales (20 vs. 16). Altigena lippa, from the Lower Mekong River basin in Lao PDR, Myanmar, Thailand, and Vietnam is also re-described. Four species of Altigena are herein recognized in the Mekong River basin A. elegans, A. laticeps, A. lippa, and A. yunnanensis.