The genus Acrossocheilus is restricted to southern China, northern Vietnam and northern Laos. It can be distinguished from related genera by the following combination of characters: rostral fold present; lips fleshy and continuous around corners of mouth; lower lip with a median interruption; mouth inferior; horny sheath on lower jaw; two pairs of barbels; last simple ray of dorsal fin osseous with a serrated or smooth posterior margin.

Originally known only from Johor and Pahang states, Peninsular Malaysia but since recorded from the Batang Hari river drainage, Sumatra and the Kapuas system, Kalimantan Barat (West Kalimantan) province, Indonesian Borneo. Type locality is ‘Tahan River, Pahang, Malaysia’.

The water at the type locality is described as ‘clear and fast-flowing over a rocky substratum’. H. parclitella was observed in shallow water among the rocks, and sympatric species included Garra cambodgiensis, Neolissochilus soroides, Poropuntius smedleyi, ‘Puntius‘ binotatus, Homaloptera nebulosa and Amblyceps mangois.

This species is occasionally marketed as ‘Burmese Rainbow Barb’ in the ornamental trade. others may have been exported in small numbers or as bycatch among shipments of other species.

It was referred to as Mystacoleucus marginatus for decades, but that name is a simultaneous subjective synonym of M. obtusirostris following Kottelat (2013).