Slender Corydoras Care Guide
Corydoras gracilis is a dwarf armoured catfish from the central Amazon basin of Brazil, suited to small soft-water aquaria.
Compiled by Aquairi from published sources · Published · Updated
Overview
Corydoras gracilis is a dwarf armoured catfish of the family Callichthyidae, described by Nijssen and Isbrucker in 1976 and currently placed by FishBase in the genus Gastrodermus. It occurs in the middle and lower Amazon basin and is one of the smallest members of the group, reaching a maximum standard length of only about 2.3 to 4 cm.
Taxonomy
- Family: Callichthyidae
- Genus: Corydoras
- Scientific name: Corydoras gracilis
- Authors: Nijssen & Isbrucker, 1976
- Current placement: Gastrodermus gracilis (FishBase)
Habitat
FishBase records the species from the middle and lower Amazon basin. Seriously Fish localises it to the central Amazon basin of north-western Brazil, with the type locality a tributary of the rio Aripuana in Amazonas. It is reported to favour minor tributaries with dense riparian vegetation, submerged leaves and branches, and acidic, tannin-stained water.
Tank requirements
- Minimum tank volume: 40 L
- Temperature: 22-26 °C (72-79 °F)
- pH: 6.0-7.5
- GH: 2-12 °dGH
- Substrate: soft sand
- School size: 6 or more individuals
- Lifespan: 5-10 years
Diet
The species is an omnivorous forager. Seriously Fish notes that it accepts sinking dried foods plus live and frozen items such as bloodworm and Tubifex, and that it requires varied feeding rather than relying on aquarium waste. Foods should be small enough for this diminutive fish.
Compatibility
Corydoras gracilis is a peaceful, gregarious bottom-dwelling species. Seriously Fish recommends maintaining it in groups of at least 4-6 individuals and notes that, despite its small size, it is a bottom-dweller rather than a mid-water schooler. Its small adult size makes it suitable for nano and dwarf-community aquaria with similarly peaceful tankmates.
Breeding
Seriously Fish suggests using two or more males per female and triggering spawning with large water changes (50-70%) using cooler water and increased oxygenation. Eggs incubate for roughly 3-4 days, and fry require small live foods and excellent water quality.
Conservation status
IUCN Red List: Least Concern (assessed 2018). FishBase rates the species as having high resilience.
Breeding Corydoras gracilis (Slender Cory)
Overview
Corydoras gracilis is a dwarf armoured catfish (family Callichthyidae) from the central Amazon basin in northwestern Brazil, reaching about 30–40 mm. It is an egg-depositor that spawns in the Corydoras T-position and can be bred in a tank with a base footprint from about 60 × 30 cm.
Sexing
Females tend to grow larger, and sexually mature individuals are noticeably broader and deeper-bodied than males, most obvious from above when females are full of eggs.
Conditioning
Condition adults on a varied diet of small live and frozen foods until the females are visibly full of eggs. Use a ratio of two or more males per female if possible.
Breeding Setup
- Temperature: 20–26 °C
- pH: 5.0–7.5
- Hardness: 36–215 ppm
- Provide glass, fine-leaved plants and/or sunken spawning mops; mops are recommended because they facilitate easy egg removal
Spawning Behavior & Trigger
When the females are visibly full of eggs, perform a large (50–70%) water change with cooler water and increase oxygenation and flow in the tank. Repeat daily until the fish spawn. The female cups the sticky eggs between her pelvic fins, fertilises them in the T-position, and deposits them on glass, fine-leaved vegetation or a mop.
Egg & Fry Care
Incubation is normally 3–4 days. Once the fry have fully absorbed their yolk sacs they accept small live foods such as microworm and Artemia nauplii. They are not the easiest to raise, requiring excellent water quality, but seem less susceptible to ailments when maintained over a thin layer of sand rather than in a bare arrangement.
Common Challenges
Fungus prevention involves adding a few drops of methylene blue or an alder cone or two to the egg container.