Hoplisoma concolor

Corydoras: from the Ancient Greek κόρυς (korus), meaning 'helmet', and δορά (dora), meaning 'skin, hide of an animal', in allusion to the rows of bony plates on the flanks of genus members.

concolor: from the Latin concolor, meaning 'of uniform colour'.

Restricted to parts of the Orinoco river system in western Venezuela.

Type locality is 'Las Mangas, in a tributary of Río Parguaza, western Bolivar State, Venezuela, 6°20'N, 67°10'W.'

Minimum base dimensions of 80 ∗ 30 cm31 ∗ 12 in or equivalent are recommended for long-term care.

Ideally use a substrate of fine sand, although rounded gravel is an acceptable alternative provided it's kept scrupulously clean.

Other décor is largely down to personal choice, but some cover should be provided to give the fish security.

Corydoras spp. are foraging omnivores and will accept most sinking dried foods, as well as small live and frozen varieties such as bloodworm, Tubifex, etc.

Feeding a varied diet will ensure the fish are in optimum condition.

Under no circumstances should they be expected to survive on 'left-overs' from other inhabitants of the aquarium or relied on to 'clean' the aquarium.

Peaceful and gregarious. Should be maintained in a group of at least 4-6 individuals.

Mature males develop an extended dorsal fin. Females tend to grow larger, and sexually mature individuals are noticeably rounder and broader-bodied than males, especially when gravid.

Eggs are normally deposited on the aquarium glass, or among fine-leaved vegetation.

Once spawning is complete the eggs can be left alone or removed. Under the latter cicrcumstances the new container should contain the same water as the spawning tank and be similarly well-oxygenated. Most breeders add a few drops of methylene blue, or an alder cone or two at this point in order to prevent the eggs developing fungus.

Incubation is normally 3-4 days and once the fry have fully-absorbed their yolk sacs they are able to accept small live foods such as microworm, Artemia nauplii, etc.

They seem less susceptible to ailments when maintained over a thin layer of sand rather than in a bare-bottomed arrangement.

This species can be told apart from congeners by its uniformly greyish colour pattern, deep body (fitting 2.1-2.4 times in standard length), large eye (3.2-4.0 times in head length), having the pectoral fins completely surrounded by the coracoid, and relatively long dorsal-fin spine (1.1-1.2 times in head length).

Until 2024 this species was placed in Corydoras, then among the largest catfish genera with over 150 valid species. Dias et al. (2024) divided it into five genera and moved this species to Hoplisoma.

It is included in the family Callichthyidae, of which members are often referred to collectively as 'armoured' or 'mailed' catfishes group due to the presence of bony plates in place of scales on the body.

Their taxonomy can be confusing, and numerous undescribed species are also thought to exist.

Fish of unconfirmed identification entering the aquarium hobby are therefore typically assigned a 'C' or 'CW' number for purposes of reference and organisation.

They are facultative air breathers and possess a modified, highly vascularised intestine which has evolved to facilitate uptake of atmospheric oxygen and aid survival in oxygen-deprived environments. In the aquarium you'll occasionally see them rising to the surface to take in gulps of air.

The stiffened pectoral-fin spines are capable of piercing human skin and a 'sting' can be very painful indeed, so care should be exercised when handling them.

It is thought that secretions from the axillary glands at the base of each spine may even be mildly toxic or venomous.