Corydoras Catfish

Corydoras is a large genus of small armoured catfish from South America, with dozens of species in the hobby such as the bronze, peppered and panda cory. They are covered in bony plates rather than scales and have sensitive whisker-like barbels they use to sift the substrate for food.

Tank & water. Most common corydoras reach 5–7 cm (2–3 in) and suit a 57–75 litre (15–20 US gallon) tank in a group. They tolerate a broad range but generally prefer pH 6.5–7.5 and temperatures of 22–26 °C (72–79 °F); a few species have narrower needs, so check the specific type. A soft sand or smooth-gravel substrate is important — sharp gravel wears down and infects their barbels.

Temperament. Corydoras are gentle, social bottom-dwellers that should be kept in a shoal of at least six; in larger groups they are far more active and confident. They coexist peacefully with small and mid-sized community fish and are a natural companion to tetras and other peaceful mid-water species.

Diet & care. They are omnivorous scavengers but must not be left to "clean up" the leftovers of other fish — they need their own sinking food, such as catfish pellets or wafers, plus occasional frozen foods like bloodworm; food that reaches the bottom is what they actually eat. They dash to the surface to gulp a bubble of air from time to time, which is normal intestinal air-breathing and not a sign of poor water. Corydoras also have mildly venomous defensive spines in their fins, so handle them with care and net them gently. A well-fed cory group is a hardy, long-lived and endearing addition to a community tank, and many species live well beyond five years in good conditions.