Native to continental China, the Korean peninsula, and southern Japan. Type locality is given only as ‘Lakes and rivers, northern China’, with the type series possibly originating from the Pai-ho River near Beijing.

It has been widely introduced and is considered invasive elsewhere, including the Mekong river basin (records from Laos and Thailand), Salween river (Myanmar), northern Japan, Taiwan, Turkmeni…

The genus Sundasalanx is distributed throughout much of Southeast Asia and currently comprises seven species which have primarily been distinguished on the basis of oral and dental morphology, gill rakers and eye size. S. microps possesses 0-3 small conical teeth on ceratobranchial 5, 0-2 minute gill rakers on the first arch and a small eye measuring less…

Occurs naturally in Brazil, Paraguay, Uruguay and Argentina with feral populations in Australia, New Zealand, Ethiopia and Malawi which were purportedly introduced for purposes of mosquito control but are now considered invasive.

Following Lucinda (2008) its natural range comprises the Lagoa dos Patos system, lower rio Uruguai, rio Tramandaí, and rio Mampituba in Rio Grande do Sul st…

This species is also referred to as ‘clown knifefish’ in the aquarium trade. It arguably has no place in the ornamental hobby given its adult size and specialised requirements but remains inexplicably popular and an albino form has even been line-bred for the purpose.

It can be distinguished from all congeners by presence of one or more rows of large ocellated spots above the base of the anal-fin, but…

This species is not collected for the aquarium trade at time of writing.

In contrast to other members of the genus older juvenile and adult individuals lack dark markings on the body while the jaw is more pronounced.

This species’ distribution is unclear although individuals from the aquarium trade are said to have been collected in the Tenasserim river basin in Tananthayi Region, southern Myanmar.

Type locality is ‘supposedly from Tananthayi district, Tananthayi River basin, obtained dead from aquarium fish vendor at Meik’.

Endemic to the Río Atrato drainage in Choco and Antioquia departments, northwestern Colombia, where the full extent of its range is somewhat unclear.

Type locality is ‘Río Truandó, a tributary of Lower Río Atrato, Colombia’, and it may be restricted to that system.

This species is exceptionally rare in the aquarium hobby.

Among congeners it is most similar to C. lacrimostigmata but can be distinguished by…

Although described as a member of Corydoras this species was later moved into the genus Osteogaster by Cope (1894), but this was later synonymised with Corydoras by Gosline (1940).

It is sometimes confused with C. venezuelanus, while two similar-looking, unidentified fishes from Peru have been assigned the codes CW007 and CW043, respectively.

This small species can be told apart from the similar-looking congener C. habrosus by possession of 4-5 (vs. 2-3) dark markings along the side of the body.