Re-description of the holotype of Lefua sayu (Teleostei: Nemacheilidae), and comments on its generic attribution

Lefua sayu (Herre and Lin 1936) was originally described from the upper Tsien Tang River, Chekiang Province, China, and the holotype remains the only known specimen. This study re-describes the holotype of Lefua sayu. The species shares certain characteristics with members of the genus Lefua, including the presence of tube-like anterior nostrils, separated anterior and posterior nostrils, a rounded caudal fin, and the absence of an epural. However, other features, such as the presence of dusky cross bars on the dorsal area of the body, a dusky bar beside the dorsal fin base, lateral line pores, cephalic lateral line pores, a relatively short nasal barbel, an anterior nostril positioned approximately midway between the base and tip of the nasal barbel, and a completely inferior mouth, differ significantly from other species of the genus Lefua. This study tentatively classifies the species within the genus Lefua, but further study is required to confirm its generic assignment.