Urucu Cory
Corydoras urucu
Small and rare species discovered in the Rio Urucu. It has an unusual pale olive-gray body, without the classic evident bands, but with very light brown speckling and a compact silhouette.
Water Temperature
22 - 26 °C
pH Value
6 - 7.2
Water type
Freshwater
Tank level
Bottom
Adult size
4.5 cm
Minimum tank volume
>= 80 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 Urucu River basin in the state of Amazonas, Brazil. Inhabits small slow-flowing forest streams and oxbow lakes (Igarapés) with mixed bottoms of sand, mud, and abundant decaying plant material.
Taxonomy and Morphology: Urucu Corydoras (Corydoras urucu). Belonging to the short-snouted Corydoras group. The specific name derives from the river of origin. Possesses the typical armor of two rows of overlapping bony plates on the flanks and double sensory barbels.
Social Behavior: Highly gregarious and peaceful. Forms cohesive groups that spend the day scouring the bottom. Keep in schools of at least 6-8 specimens to avoid severe stress and fearful behavior.
Coloration and Sexual Dimorphism: Light cream-white body, characterized by a thick dark mask (blindfold) covering the eye, a dark spot at the base of the dorsal fin, and speckles along the flanks. Females noticeably rounder when viewed from above.
Care, breeding and tankmates
Aquarium Setup: Minimum 60-80 cm (24-32 inches) aquarium. A very fine, non-sharp sand bottom is essential to preserve the barbels. Roots, branches, and a layer of dried oak or catappa leaves will recreate the ideal environment.
Diet and Feeding: Benthic micro-predator. Not a waste cleaner. Offer daily protein sinking granules, live/frozen bloodworms, tubifex, and brine shrimp. A varied diet prevents malnutrition diseases.
Water Quality: Requires soft (GH 2-12) and slightly acidic to neutral waters (pH 6.0-7.2). Extremely intolerant towards nitrate accumulation and dirty bottoms, which cause immediate bacterial infections to the barbels.
Compatibility and Cohabitation: Ideal fish for quiet South American community aquariums. Excellent companions include small Tetras, Nannostomus, peaceful Loricariids, and docile dwarf Cichlids. Avoid keeping with large or aggressive Cichlids.
Aquarium Breeding: Difficult. Stimulated by temperature drops through cool water changes and abundant live food. The female lays a few adhesive eggs, usually hidden among broad leaves or moss filaments. Parents prey on the eggs.
Risks and Diseases: Barbel erosion on rough or sharp gravel is the most frequent cause of death, leading to septicemia. Totally intolerant to copper compounds and table salt.
Geographic Origin and Distribution
Endemic to the Urucu River basin in the state of Amazonas, Brazil. Inhabits small slow-flowing forest streams and oxbow lakes (Igarapés) with mixed bottoms of sand, mud, and abundant decaying plant material.
Origin
Tropical oceans and reefsAmazon, Orinoco, and Guianas
Fish profile
- Temperament
- Semi-aggressive
- This is an incredibly peaceful and timid species that thrives in the company of its own kind. Corydoras urucu should be kept in groups of at least six individuals to feel secure and display their natural, endearing behaviors. When kept alone or in too small a group, they can become highly stressed, lethargic, and prone to illness.
- Diet
- Omnivore
- As omnivorous bottom feeders, Corydoras urucu requires a varied diet that sinks to the substrate. High-quality sinking pellets or wafers should form the staple of their diet. Supplementing with live or frozen foods like bloodworms, brine shrimp, and daphnia will ensure optimal health and encourage natural foraging behaviors.
- Life expectancy
- 5-8 years
- The life expectancy of this species in the aquarium ranges from 5 to 8 years, provided the environment is kept clean and stable. It is essential to ensure a fine sandy substrate to protect the delicate barbels from infections that would compromise their survival. Periodic water changes and nitrate monitoring are the basis for keeping them in shape long term.
- Adult size
- 4.5 cm
- The catalog's scalar value is 4.5 cm. The FishBase SPECIES table (v25.04 snapshot) source reports a maximum adult measurement of 2.75 cm for this species, recorded as standard length (SL). The taxonomic record consulted is Corydoras urucu (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
- Specific M:F ratio
- A ratio of two or three males for every female is highly recommended, especially if breeding Corydoras urucu is the goal. Males are generally smaller and more slender than the plumper, rounder females. Maintaining a proper sex ratio ensures higher fertilization rates during the spawning process.
- Feeding frequency
- Twice daily
- Corydoras urucu should be fed small amounts once or twice a day, providing only what they can consume within a few minutes. Because they are nocturnal foragers by nature, dropping some food in just before the aquarium lights go out can be highly beneficial. Avoid overfeeding to maintain excellent water quality.
- Bioload
- This species produces a relatively small bioload, typical of most Corydoras urucu species. Their efficient scavenging behavior can actually help keep the substrate clean, reducing the overall accumulation of detritus. Regular water changes and a properly sized filter will easily manage the waste they produce.
- Flow
- Stagnant
- These catfish prefer moderate water flow that provides adequate oxygenation without creating overpowering currents. A setup that mimics a slow-moving South American stream is ideal for Corydoras urucu. Ensure there are calmer resting areas where they can settle on the substrate without expending too much energy.
- Reproduction
- Oviparous
- Breeding Corydoras urucu in captivity can be achieved by simulating the onset of the rainy season with cooler water changes. The female will carry a few eggs in a pouch formed by her pelvic fins and deposit them on broad leaves or the aquarium glass. The parents exhibit no parental care and will eagerly consume the eggs if not separated.
- Compatibility & tankmates
- Corydoras urucu is a peaceful and highly sociable schooling fish that makes an excellent addition to community aquariums. They do best when kept with other small, non-aggressive species such as tetras, rasboras, and dwarf cichlids. It is crucial to avoid housing them with large or aggressive bottom-dwellers that might outcompete them for food or stress them out.
- Tank level
- Bottom
- Like other Corydoras, Corydoras urucu are quintessential bottom dwellers, spending almost all of their time sifting through the substrate in search of food. They require a soft, sandy bottom to prevent damage to their sensitive barbels. Occasionally, they will make quick dashes to the surface to take in atmospheric air, a completely normal behavior.
Scientific Parameters & Models
FishBase
Window to the official scientific data of the species
Data synced on: 06/15/2026
- Trophic level
- 3 ± 0.4 se
- Phylogenetic uniqueness (PD50)
- 0.5
- Bayesian Length-Weight
- a = 0.01778, b = 3.02
- VulnerabilityLow vulnerability (10 / 100)
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
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