Bronze (Green) Corydoras

These small catfish are very popular occupants of community aquariums, agreeing well with other non-aggressive fish. They are very easy to look after, and may attempt to breed in the aquarium too, although if they are not removed, their eggs are likely to end up being eaten by the other tank occupants.

Bronze corydoras (Corydoras aeneus) grow to a maximum size of about 7.5cm (3in). Females tend to be larger than males but bear in mind when choosing a likely pair that a smaller fish could simply be younger. The natural colour of the bronze corydoras, as its name suggests, is reddish-brown, resembling bronze, often with a greenish sheen, but there is also now a very striking albino form with a pure white body and red eyes that has been developed by fish-keepers.

In the wild, these catfish are widely distributed across northern South America, from the Caribbean island of Trindad south to Brazil. There is some variation in their appearance through their massive range, with one of the best-known variants displaying golden streaks across the head. These are not especially active fish by nature, occupying the lower level of the aquarium. It is quite normal for them to rest here on pieces of bogwood and even directly on the aquarium gravel, rather than being a sign of illness. A water temperature of 25°C (77°F) suits them well.

Although bronze corydoras will eat food that other fish miss, which then drops to the floor of the tank, they should not be expected to thrive just on leftovers. They can be offered special catfish pellets and other items such as bloodworm, with small pieces of prawn being a particular favourite.

For breeding purposes, it is preferable to keep bronze corydoras in a tank on their own, in trios consisting of a male and two females. Lowering the water temperature slightly at night can act as a spawning trigger, with females swelling with eggs beforehand.