Hoplisoma loxozonum

The False Bandit Cory, also known as the Slant-bar Corydoras, is a charming and peaceful bottom-dwelling fish perfect for many community aquariums. Originating from South America, this small catfish is easily recognized by the distinct, dark diagonal stripe that runs from the back of its dorsal fin down towards its tail, giving it a 'masked' appearance. They are very social creatures and feel most comfortable in a group, so you should always keep them with several of their own kind. A small, lonely cory will often be shy and stressed.

In your aquarium, these fish will spend most of their time exploring the bottom, sifting through the substrate for bits of food with their sensitive whisker-like barbels. Because of this, it's essential to provide them with a soft, sandy bottom to prevent injury. Sharp gravel can damage their barbels, leading to infection.

They are not picky eaters and will happily accept a variety of sinking foods, such as pellets and wafers, as well as frozen or live treats. Just make sure the food reaches them at the bottom! For tank mates, choose other small, peaceful fish. Very large or overly active fish can intimidate them, causing stress and making it hard for them to compete for food. A unique trait is their ability to occasionally dart to the surface for a gulp of air, which is completely normal. They are a delightful, moderately active addition that brings life to the lower levels of your tank.

Hoplisoma loxozonum, commonly sold as the False Bandit Cory, is a sought-after species among hobbyists for its peaceful demeanor and distinct markings. The specific name loxozonum derives from Greek, meaning 'slanting-banded,' which accurately describes the diagonal black bar that serves as its key identifying feature. This marking distinguishes it from the true Bandit Cory, Corydoras metae, whose stripe follows the upper contour of its body. Native to slow-moving tributaries and floodplain waters in South America, this species is adapted to environments with soft, sandy substrates, abundant leaf litter, and low water flow. Replicating this biotope is the key to their long-term health.

A dedicated setup should feature a fine sand substrate to protect their delicate oral barbels, which are vital for foraging and are prone to erosion and infection on coarse gravel. Dim lighting, along with driftwood branches and dried botanicals like catappa leaves, will not only provide necessary cover but also encourage the growth of biofilm, which these fish graze upon as a supplemental food source. While adaptable to a range of pH and hardness, they thrive in stable, clean water with low nitrate levels, reflecting their low bioload but sensitivity to organic waste. Filtration should be gentle; using a spray bar to diffuse the outflow is highly recommended to avoid creating strong currents they are not built for.

Socially, their shoaling instinct is strong. A group of five is the absolute minimum, but a larger shoal of eight or more will result in more confident, active, and natural behavior. They are excellent community fish but are easily stressed by boisterous tank mates that outcompete them for food. Ideal companions include small tetras, rasboras, and other dwarf cichlids. A varied, omnivorous diet is crucial. High-quality sinking pellets and wafers should be the staple, supplemented regularly with frozen or live foods like bloodworms, daphnia, and brine shrimp to ensure optimal nutrition and conditioning. A fascinating physiological trait is their ability to utilize atmospheric air for respiration via a modified intestine. While an occasional dash to the surface is normal, frequent air-gulping can be an indicator of low dissolved oxygen or poor water quality. Breeding is moderately difficult but achievable, typically triggered by a large, cool water change simulating seasonal rainfall, which encourages them to lay their adhesive eggs on tank glass and decor.

Hoplisoma loxozonum is a species of armored catfish belonging to the family Callichthyidae and the subfamily Corydoradinae. Described by Nijssen & Isbrücker in 1983, it was recently reclassified from the genus Corydoras to Hoplisoma following extensive phylogenetic revision of the subfamily. This species is native to the upper Meta River basin, a tributary of the Orinoco in Colombia, where it inhabits lentic environments such as floodplain lakes and slow-moving, typically clear or blackwater, forest streams (igarapés).

The primary diagnostic feature distinguishing H. loxozonum is the prominent, oblique, dark dermal stripe extending from the posterior insertion of the dorsal fin ventrocaudally toward the lower part of the caudal peduncle. Morphologically, it possesses a fusiform body shape typical of the genus, armored with two rows of overlapping bony plates. Its ventral mouth is equipped with sensitive barbels used for chemoreception to locate food within benthic substrates. Ecologically, it functions as a micro-predator and detritivore, consuming small invertebrates, crustaceans, and aufwuchs (biofilm).

Physiologically, H. loxozonum exhibits several key adaptations. It is a facultative air-breather, capable of utilizing atmospheric oxygen through a highly vascularized posterior intestine. This adaptation allows it to thrive in hypoxic conditions that may seasonally occur in its natural habitat. Its metabolism and corresponding oxygen consumption are low. The species is strictly freshwater (stenohaline) and has evolved to tolerate the ion-poor, acidic to neutral waters of its native range, though it demonstrates a degree of plasticity in aquarium settings. The bioload factor is relatively low, reflecting modest waste production.

Reproductive behavior is characteristic of the Corydoradinae group, involving the well-documented 'T-position' during fertilization. They are non-guarding, egg-scattering spawners that deposit adhesive eggs onto various surfaces. Spawning events in situ are likely triggered by environmental cues such as changes in water temperature and chemistry associated with the onset of the rainy season. The current IUCN Red List status for H. loxozonum is 'Data Deficient' (DD), indicating that insufficient population and distribution data exist to accurately assess its extinction risk, highlighting a need for further field research.