Robust Cory
Corydoras robustus
The colossus of the family: an extraordinary 'long snout' that almost reaches 10 cm, with powerful armored scales, pale spotted livery and a very high sail dorsal fin in males.
Water Temperature
22 - 26 °C
pH Value
6 - 7.2
Water type
Freshwater
Tank level
Bottom
Adult size
8.5 cm
Minimum tank volume
>= 150 L
Minimum group
>= 6
GH
2 - 12 dGH
KH
2 - 10 dKH
TDS
50 - 280 ppm
Conductivity
78 - 438 uS/cm
Species description
Geographical Origin and Habitat: Endemic to the Rio Purus basin, a gigantic right tributary of the Amazon River in Brazil. The habitat is dominated by extensive lagoons, oxbow lakes, or very slow-flowing rivers, where the animal dominates sandy banks covered with mud and decaying plant remains.
Taxonomy and Morphology: As the specific epithet "robustus" suggests, it is among the absolute giants of the Callichthyidae family. Easily touches 8.5 - 9 cm (3.3-3.5 inches). In addition to the titanic body, it belongs to the long-snouted strain, boasting an elongated snout of a true excavator.
Social Behavior: Despite its grandeur, it is a very fearful fish and vulnerable to stress. Isolation or housing in pairs condemns it to grim apathy. It must strictly be inserted in large schools (6-10 specimens) to see it act with proud and calm determination.
Coloration and Sexual Dimorphism: Gray/pinkish body adorned with large broken blackish bars and a faded longitudinal band. Adult males develop a "banner" dorsal fin (disproportionate sail, high and slender), which makes them majestic and unmistakable compared to the huge rounded females.
Care, breeding and tankmates
Aquarium Setup: Huge tanks, given the size (minimum 120-150 liters for the school alone). High substrate and strictly in soft impalpable silica sand. Create vast shelters with Red Moor wood and shade abundantly to ward off exposure panic.
Diet and Feeding: Unstoppable "industrial" benthic carnivore. Demands proportionate volumes of food: highest quality bottom tablets, which must be vigorously alternated with massive doses of giant bloodworms, chopped krill, or large fresh earthworms.
Water Quality: Highly sensitive to pollutants despite its size. Neutral or weakly acidic pH (6.0 - 7.2), soft GH (2-12). The optimal temperature fluctuates between 22 and 26°C (72-79°F). The accumulation of bacterial debris consumes its barbels: conspicuous and regular water changes are necessary.
Compatibility and Cohabitation: Gentle giant. Suitable for large Amazonian biotopes with medium Tetras (Bleeding heart tetra, Congo), or peaceful Geophagus, provided they are not voracious predators that steal its vital feed.
Aquarium Breeding: Extremely rare in the aquarium; it is supposed to follow the monsoon dynamics of the genus (drastic changes with cold RO water). The egg release, following a T-position, produces limited clutches subject to very high parental cannibalism.
Risks and Diseases: Fungal necrosis of the barbels on unsuitable bottoms (sharp quartz) is an atrocious death sentence. High lethality found in the incorrect use or high doses of chemical curatives (Copper and Malachite green).
Geographic Origin and Distribution
Endemic to the Rio Purus basin, a gigantic right tributary of the Amazon River in Brazil. The habitat is dominated by extensive lagoons, oxbow lakes, or very slow-flowing rivers, where the animal dominates sandy banks covered with mud and decaying plant remains.
Origin
Amazon, Orinoco, and Guianas
Fish profile
- Temperament
- Semi-aggressive
- The temperament of Corydoras robustus is exceedingly peaceful and sociable, making them a favorite among community tank enthusiasts. They show absolutely no aggression towards other fish species and prefer to go about their daily foraging undisturbed. They are highly gregarious and derive comfort from the presence of their own kind, frequently resting and moving together as a unified group. Isolation can cause them immense stress, resulting in hiding and refusing to eat.
- Diet
- Omnivore
- Corydoras robustus are omnivorous bottom feeders that require a varied diet to thrive in captivity. A high-quality sinking pellet or wafer specifically formulated for bottom dwellers should form the staple of their daily meals. They also greatly benefit from regular offerings of live or frozen foods such as bloodworms, daphnia, and brine shrimp. It is important to ensure that food reaches the bottom before being consumed by mid-water fish so they do not go hungry.
- Life expectancy
- 5-8 years
- As one of the largest species in the genus, the Robust Corydoras has an average lifespan of 5 to 8 years in captivity, potentially reaching 10 years under ideal conditions. Their substantial body size requires spacious aquariums and high-capacity filtration to manage the bioload. Maintaining stable water parameters and a clean substrate is essential to prevent infections and ensure long-term health. A soft, inert sandy substrate is mandatory to protect their large, sensitive sensory barbels.
- Adult size
- 8.5 cm
- The catalog's scalar value is 8.5 cm. The FishBase SPECIES table (v25.04 snapshot) source reports a maximum adult measurement of 7.12 cm for this species, recorded as standard length (SL). The taxonomic record consulted is Corydoras robustus (v25.04); male or unsexed record. These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
- Sex ratio
- School
- A recommended sex ratio for Corydoras robustus, especially if breeding is desired, is two or three males for every female. This mimics their natural breeding groups and increases the chances of successful fertilization of the eggs. In a standard display tank, exact ratios are less critical as long as they are kept in a sufficiently large shoal of six or more. Having more males ensures that the female is constantly courted during the breeding cycle.
- Feeding frequency
- Twice daily
- Feeding Corydoras robustus one or two times a day is generally sufficient to maintain their health and vitality. Care should be taken to provide only what they can actively consume within three to five minutes to prevent water fouling. If kept in a community setup with aggressive surface feeders, it may be beneficial to feed them after lights out. Observing their belly fullness can help determine if the feeding frequency and amounts are appropriate.
- Bioload
- Corydoras robustus produces a moderate bioload, making them excellent candidates for community tanks. Their efficient scavenging habits actually help maintain water quality by consuming uneaten food that would otherwise decay. Despite their modest size, a school of six or more does contribute somewhat to the tank's waste output. Regular water changes and adequate filtration are still necessary to keep the bioload manageable and nitrate levels low.
- Flow
- Stagnant
- This species prefers gentle to moderate water flow that mimics the slow-moving streams and tributaries of Amazon and Pantanal basins. Excessive flow can cause unnecessary stress and fatigue, as they are not built for constant swimming against strong currents. A well-placed sponge filter or a canister filter with a spray bar can provide the ideal balance of filtration and gentle water movement. Oxygenation remains important, so ensuring surface agitation without overpowering the bottom areas is key.
- Reproduction
- Oviparous
- Breeding Corydoras robustus can be achieved in a dedicated breeding setup with cool water changes used to trigger spawning behavior. The females are typically larger and more robust, scattering adhesive eggs onto broad-leaved plants, aquarium glass, or spawning mops. Once spawning is complete, the adult fish should be removed to prevent them from eating the eggs. The fry hatch after a few days and require very small live foods like microworms or freshly hatched brine shrimp.
- Compatibility & tankmates
- These peaceful catfish are highly compatible with a wide variety of community fish. They do exceptionally well with small tetras, rasboras, and dwarf cichlids that inhabit the middle and upper levels of the aquarium. Aggressive or large bottom-dwelling species should be avoided as they may bully the Corydoras robustus or outcompete them for food. Keeping them in groups of at least six of their own kind is vital for their sense of security.
- Tank level
- Bottom
- Corydoras robustus are strictly bottom dwellers, spending almost the entirety of their day sifting through the substrate in search of food. They require a soft, sandy substrate to prevent damage to their delicate barbels, which are essential for sensing their environment. While they occasionally dart to the surface to take in a breath of atmospheric air, they immediately return to the bottom. Decor elements like caves, driftwood, and low-lying plants provide them with much-needed resting spots.
Scientific Parameters & Models
FishBase
Window to the official scientific data of the species
Data synced on: 06/15/2026
- Trophic level
- 2.9 ± 0.3 se
- Resilience
- High (less than 15 months)
- Phylogenetic uniqueness (PD50)
- 0.5
- Bayesian Length-Weight
- a = 0.02455, b = 3
- VulnerabilityLow vulnerability (10 / 100)
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
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