Gray Cory Care Guide - Aquarium Setup, Diet & Breeding

The Gray Cory, Corydoras griseus, is a small, appealing armoured catfish with a predominantly silvery-grey body and subtle darker markings. Like other Corydoras, it has rows of bony plates along its flanks and a pair of sensitive barbels around the mouth for locating food across the substrate.

This species is peaceful and sociable, spending much of its time exploring the bottom but regularly darting to the surface to gulp air. Its ability to take occasional atmospheric oxygen is a natural adaptation rather than a substitute for clean, well-oxygenated water.

Gray Corydoras are active, curious fish that become more confident when kept in a proper group. They often rest together among plants or beneath shaded cover, then fan across the bottom in search of small edible items.

In the wild, they inhabit quiet or gently flowing forest waters where sand, fine sediment, leaf litter and submerged roots create a complex mosaic of feeding and sheltering places. Their understated colouring helps them blend into this subdued environment.

Gray Corydoras come from northern Brazil in South America, where they are associated with the Rio Jari drainage in the eastern Amazon region. Their natural waters are typically warm, soft and lightly acidic, with sandy areas and organic debris from surrounding forest.

A group of Gray Corydoras should have at least 60 litres, with a footprint of approximately 60 by 30 cm; a longer aquarium is preferable because floor area matters more than height. Use smooth fine sand or another rounded, soft substrate to protect their delicate barbels, and provide shaded areas with plants, wood, leaf litter and smooth rock. Gentle water movement, good filtration and open areas for foraging are important, while a secure lid is useful because Corydoras may leap when startled.

Gray Corydoras reach a maximum of about 4 cm (1.6 inches) in standard length. Females are usually slightly larger and fuller-bodied than males, particularly when mature and carrying eggs.

Gray Corydoras are omnivorous foragers that need a varied diet rather than leftover flakes alone. Offer sinking, high-quality catfish pellets or wafers as a staple, supplemented with frozen or live foods such as bloodworm, daphnia, brine shrimp and finely chopped aquatic invertebrates. Blanched vegetables can occasionally be offered, but uneaten food should be removed promptly. Make sure food reaches the bottom so the catfish are not forced to compete with midwater fish.

Gray Corydoras are excellent community fish and can be kept with peaceful small tetras, rasboras, danios, pencilfish, peaceful livebearers and other gentle South American species. They also mix well with small, non-territorial dwarf cichlids and other peaceful Corydoras when space and groups are adequate. Avoid large or aggressive cichlids, fin-nipping species and boisterous bottom dwellers, as well as potentially predatory fish that may swallow them. Do not keep them with aquarium salt or copper-based treatments unless their safety has been carefully confirmed.

Gray Corydoras are egg-scattering spawners that can be encouraged to breed in a mature, well-maintained aquarium. Condition a group with plenty of high-quality foods, including live or frozen options, then stimulate spawning with a partial water change using slightly cooler water. The female carries a few adhesive eggs between her pelvic fins before placing them on plant leaves, aquarium glass or other smooth surfaces, while the male fertilises them. Parents may eat the eggs, so remove the adults or protect the eggs and raise the fry on tiny first foods such as powdered fry food and newly hatched brine shrimp.

Females are generally broader through the body and a little longer, while males are slimmer and more streamlined. The difference is most obvious when viewed from above, especially when a mature female is full of eggs.