Acrossocheilus paradoxus

Acrossocheilus: from the Greek a- (Gr. ἀ-), meaning 'without', krossós (Gr. κροσσός), meaning 'fringe, tassel', and cheílos (Gr. χείλος), meaning 'lip', in reference to the smooth upper lip in members of this genus.

paradoxus: Latin term meaning 'strange, contrary to expectation', in reference to a “very singular variation” in the type series because one individual had a “considerably produced” snout compared with the others.

Native to Taiwan, where it occurs throughout western and northeastern river drainages, plus Fujian and Zhejiang provinces, mainland China. No specific type locality is provided in Günther's description.

Inhabits subtropical streams and small-to-medium sized rivers at medium to relatively high altitudes.

An aquarium with base dimensions of 180 ∗ 45 cm72 ∗ 18 in or equivalent should be the smallest considered for long-term maintenance.

Likely to prefer a set-up designed to resemble a flowing river with a substrate of variably-sized rocks and gravel and some large water-worn boulders. This can be further furnished with driftwood roots and branches arranged to form some shaded spots.

While the vast majority of plant species will fail to thrive in such surroundings hardy types such as Microsorum, Bolbitis or Anubias can be grown attached to the décor and bright lighting will promote the growth of aufwuchs upon which the fish will graze.

Like many fishes that naturally inhabit running water it is intolerant to the accumulation of organic wastes and requires spotless conditions in order to thrive, meaning weekly water changes of 30-50% tank volume should be considered routine. Though torrent-like conditions are unnecessary it also does best if there is a high level of dissolved oxygen and moderate water movement.

Since it doesn't cope well with fluctuating water conditions try to acclimatise it to the aquarium over a couple of hours if possible, and it should never be introduced to a biologically immature system.

Wild fish are known to feed on small, benthic invertebrates and graze biofilm from rocks and other solid surfaces.

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.

Members of the genus are characterised by possessing a particular number of dark vertical bar on each flank, and A. paradoxus belongs to a group of species with five or six such bars, each of which is two scales in width. Congeners sharing this pattern include A. fasciatus, A. hemispinus (in juveniles only), A. jishouensis, A. kreyenbergii, A. parallens, A. spinifer, A. wenchowensis, and A. wuyiensis.

The nominal species A. labiatus is currently considered synonymous with A. paradoxus according to some sources although this appears to be in question.