Reynolds's Cory
Corydoras reynoldsi
A charming Colombian jewel easily identified by three bold blackish spots along its golden-hued flanks. It depends on impalpable sand and amber waters to remain healthy and vibrant.
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: Colombian endemism, limited to the Caquetá river basin. The colonies of C. reynoldsi reside within forest peat bogs, igarapés, and slow channels, dominated by dense carpets of aquatic plants and a thick sandy/muddy bottom.
Taxonomy and Morphology: Graceful Corydoras with a compact and rounded cephalic profile ("short-snouted"). Given its limited size (rarely above 4.5 cm / 1.8 inches), it falls fully into the "dwarf" corys. Stocky profile but very elegant in swimming.
Social Behavior: Calm and insecure nature. It becomes confident and extroverted only if surrounded by at least 8-10 conspecifics. Patrols the ground in sync with the school; social breakdown due to small numbers will cause them to fade away apathetically.
Coloration and Sexual Dimorphism: Often confused with C. weitzmani or tukano, it boasts three imposing and large irregular blackish patches/saddles: an eye mask, a huge spot covering the dorsal and half belly, and a bar on the tail. Pure pink body background. Mature females have massive flanks and a round build.
Care, breeding and tankmates
Aquarium Setup: Impalpable and inert sand is a fixed law to avoid infections to the small and delicate whiskers. They love intricate mazes of bog wood covered with ferns or Anubias and well-amber waters due to the extract of oak or catappa leaves.
Diet and Feeding: Micro-carnivore. Flakes and granules must be crushed to accommodate its tiny mouth. Feed them vigorously alternating crumbled wafers with full-bodied bi-weekly injections of live and frozen food: microworms, small daphnia, cyclops, and brine shrimp.
Water Quality: Classic temperatures 22-26°C (72-79°F). The pH, tendentially acidic, must stay between 6.0 and 7.2. Limited hardness (GH 2-12) is indispensable. Suffers terribly, like all dwarfs, from excesses of nitrogenous compounds, demanding constant small partial changes.
Compatibility and Cohabitation: Splendid gem for peaceful communities. Companions must not exceed 5-6 centimeters and must possess a quiet nature (Ember Tetras, Boraras, Corydoras pygmaeus, small Loricariids). Active or burrowing fish stress it mortally.
Aquarium Breeding: Rare event, triggered by conspicuous water changes with very cold RO water. In T-position, females distribute very few (but large) eggs among fine-leaved plants. Parents disown the eggs and willingly feed on them if not separated.
Risks and Diseases: Sharp gravels crack the delicate sensory barbels, condemning it to bacteriosis. Like many "scaleless" fish, it is atrociously susceptible and intolerant to standard concentrations of Copper, Salt, and Formalin used for common diseases.
Geographic Origin and Distribution
Colombian endemism, limited to the Caquetá river basin. The colonies of C. reynoldsi reside within forest peat bogs, igarapés, and slow channels, dominated by dense carpets of aquatic plants and a thick sandy/muddy bottom.
Origin
Extra-Amazon South America
Fish profile
- Temperament
- Semi-aggressive
- The temperament of Corydoras reynoldsi 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 reynoldsi 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
- 3-5 years
- Due to its small size and delicate nature, Reynolds's Corydoras has an average lifespan of 3 to 5 years in captivity, though it can reach up to 7 years with expert care. This species is highly sensitive to the accumulation of nitrogenous waste and sudden changes in water chemistry. A mature and efficient biological filtration system is essential to ensure their long-term survival. Additionally, a substrate of very fine, smooth sand is mandatory to prevent bacterial infections of their delicate barbels.
- 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 3.15 cm for this species, recorded as standard length (SL). The taxonomic record consulted is Corydoras reynoldsi (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 reynoldsi, 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 reynoldsi 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 reynoldsi 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 various South American river 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 reynoldsi 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 reynoldsi 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 reynoldsi 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
- 3 ± 0.4 se
- Resilience
- High (less than 15 months)
- 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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Recommendations grouped by close relatives, companion choices, and similar care.
