Hoplisoma metae

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.

metae: named for its type locality, the Río Meta in Colombia.

Endemic to the Río Meta, a major tributary of the Río Orinoco in eastern Colombia. It is known from several tributaries within the upper basin including the ríos Humea, Ocoa, Guatiquía (including its two branches the ríos Negrito and Guayuriba), Manacacias, and Metica (the name given to the upper Río Meta above its confluence with the Río Humea). It appears to be absent from the lower Meta and has not been recorded in Venezuela.

Type locality is 'Barrigona, Rio Meta, Colombia', corresponding to Puerto Barrigon on the Río Humea.

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 is kept scrupulously clean.

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

Corydoras spp. are foraging omnivores and will accept most sinking dried foods, as well as small live and frozen varieties such as chironomid larvae (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.

Females tend to grow larger, and sexually mature individuals are noticeably rounder and broader-bodied than males, especially when gravid.

Can be bred in a similar fashion to many other Corydoras species.

Use a ratio of two males per female if possible. When the females are visibly full of eggs perform a large (50-70%) water change with cooler water, and increase oxygenation and flow in the tank. Repeat this daily until the fish spawn.

Eggs are normally deposited on the aquarium glass, but it is recommended to provide alternatives in the form of fine-leaved vegetation or fine spawning mops.

Once spawning is complete either adults or eggs should be removed; the latter can usually be rolled gently up the glass with a finger. 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 require excellent water quality, but seem less susceptible to ailments when maintained over a thin layer of sand rather than in a bare-bottomed arrangement.

This species is also referred to as 'masked' or 'Meta' cory in the aquarium hobby. It can be distinguished from similar-looking congeners by the form of the oblique dark bar on the posterior portion of the body, which terminates at the caudal-fin base and does not extend onto the fin itself or split into two on the caudal peduncle. There are no additional dark markings on the body.

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 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.