Brochis multiradiatus

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Brochis multiradiatus is a large armored catfish from South America, valued for its sturdy shape and peaceful behavior. Long associated with the genus Corydoras, it is now generally placed in the genus Brochis. This species is distinguished by its **many dorsal-fin rays**, a feature reflected in its scientific name. Sociable by nature, it should be kept in a group and provided with a spacious aquarium containing a **soft, non-abrasive substrate**. Aquarium specimens may be **wild-collected**, making gradual acclimation and well-oxygenated water especially important. Its commercial rarity is low to moderate: it is less common than many small Corydoras, but it is not exceptionally rare.

General species description

Brochis multiradiatus is a large benthic callichthyid adapted to life on the bottom of Amazonian waterways. Its body is protected by two rows of bony plates, as in other members of the family Callichthyidae. It often moves in groups, searches the substrate with its barbels and regularly rises to the surface to gulp atmospheric air, a normal behavior in several Corydoradinae. Despite its substantial size, it has a **peaceful temperament** and suits a community aquarium containing calm fish. A group of at least six individuals encourages more natural behavior. Sufficient bottom area, effective filtration and regular water changes are important. The species is hardy when water conditions remain stable, but it does not tolerate accumulated organic waste or neglected maintenance.

Geographic origin and biotope

Brochis multiradiatus comes from the **upper Amazon Basin**, mainly around the río Napo in Ecuador, with a regional distribution that may reach the northwestern Amazon. Its natural environment consists of warm tropical freshwater, usually soft and slightly acidic to near neutral. Habitats include calm margins, secondary channels and floodplain areas where fine sand, leaves and plant debris collect. Riparian vegetation provides shade and contributes organic matter to the habitat. In aquaria, well-filtered water, **soft to moderately mineralized conditions**, good oxygenation and moderate circulation reproduce the most important features of this biotope. Because the species is regularly offered as a **wild-collected fish**, transport and acclimation should be handled carefully to reduce stress.

Precise location and local name

The reference locality generally associated with Brochis multiradiatus is the **río Napo** in Ecuador, an important Amazon tributary flowing through a humid tropical forest region. Its habitats include stream margins, side channels and slow-flowing areas where the bottom allows fish to forage. In the aquarium trade, it is mainly known as the **giant cory**, “many-rayed cory” or giant Corydoras. These common names refer to its larger size compared with many Corydoras and its particularly well-developed dorsal fin. Trade names should not replace scientific identification, since several large Corydoradinae can be confused when young or poorly photographed.

Appearance and physical characteristics

Brochis multiradiatus has a stout, deep and heavily armored body, with a broad head and an inferior mouth bearing sensory barbels. Its general coloration ranges from beige to grayish brown, usually with darker markings across the body and fins. Its most distinctive feature is the **dorsal fin with numerous rays**, giving it a noticeably taller profile than many related fish. The pectoral and dorsal fins contain locking spines, so it should be handled with a suitable net and without forcing the fins. Its large adult size calls for an aquarium with a **generous bottom area**, rather than a layout focused only on height.

General diet

Brochis multiradiatus is a benthic omnivore that searches for small prey, larvae, worms, tiny crustaceans and organic matter in the substrate. In aquaria, its diet should be based on **quality sinking tablets**, supplemented with frozen or live foods such as bloodworms, brine shrimp and mosquito larvae. Food must reach the bottom so every fish can feed properly; competition from surface-dwelling species should not deprive it of meals. Wild specimens may need several days to adjust before accepting prepared foods. A varied diet offered in small portions helps maintain body condition without overloading the water. It should not be treated as a simple cleaner fish: its nutritional requirements must be planned.

Essential data

• Native river: río Napo
• Local name used: Giant cory; many-rayed cory; giant Corydoras
• Scientific-name origin: The specific name describes the high number of rays in the dorsal fin.
• Full-name etymology: Brochis is a genus name of Greek origin; multiradiatus comes from the Latin multi, several, and radiatus, rayed or provided with rays.
• Common/vernacular names: Giant cory, many-rayed cory, giant Corydoras
• Family: Callichthyidae
• Subfamily: Corydoradinae
• Name pronunciation: bro-kiss mul-tee-ray-dee-AH-tus
• Discovery: Víctor Manuel Orcés V., 1960
• Maximum adult size: About 10 cm
• Water temperature and pH: 22 to 27 °C; pH 6.0 to 7.5
• Stream appearance and surrounding vegetation: Soft tropical water, wooded banks, shaded areas and abundant riparian vegetation.
• Typical tankmates: Pterophyllum scalare, Geophagus altifrons
• Temperament and behavior: Peaceful, social and active near the bottom; occasionally rises to the surface to breathe air.
• Water depth: —
• Sexual dimorphism: Mature females are generally broader and more robust than males, especially when viewed from above.
• Bottom structure and flow: Fine sand, leaves and plant debris; low to moderate current depending on the sector.

In your aquarium

To keep Brochis multiradiatus successfully, provide a group, a mature aquarium and a **fine sand substrate** that protects the barbels. Stable, well-oxygenated water with low organic waste is essential, particularly for wild specimens. Include open areas for foraging, a few shelters and moderate water movement. Feed varied sinking foods rather than relying on leftovers in the tank. Its **social behavior** and adult size should guide the selection of tankmates and aquarium volume.