TankBud

Rust cory

Osteogaster rabauti

Also known as Corydoras rabauti, Rusty cory, Rabaut's cory

FreshwaterFish

Rust cory (Osteogaster rabauti)
The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature
72–79°F
22–26°C
pH
5.5–7.2
Adult size
2.4 in
6 cm
Minimum tank
20 gal
75 L
Temperament
Peaceful
Social behavior
Shoaling
Swim level
Bottom
Difficulty
Easy
Breeding
Medium
Rarity
Common
Family
Callichthyidae
Origin
Upper Amazon basin in western Brazil and Peru.

Overview

The rust cory is a peaceful, shoaling fish for the bottom of a calm community tank. It is easy to keep.

Did you know

Young rust cories look nothing like the adults. Juveniles wear a stark black stripe on a pale body, and the pattern fades into coppery rust as they grow. They look so different that they were once taken for another species.

Caring for the rust cory

Keep rust cories in a group of six or more, in a tank of 20 gal (75 L) or larger. Give them smooth sand, which protects their barbels while they forage.

Keep the water soft to medium, at 72 to 79°F (22 to 26°C) with a pH of 5.5 to 7.2. Feed sinking pellets, frozen bloodworm and other small foods that reach the bottom.

Rust cories are peaceful, so pair them with calm tank mates. Breeding them is moderately difficult.

Good to know

The rust cory belongs to the family Callichthyidae. The 2024 revision of the group moved it to the resurrected genus Osteogaster, so scientific writing now calls it Osteogaster rabauti. The trade still sells it as Corydoras rabauti. A dark band running onto the lower part of the tail base separates it from the near-identical black band cory.

In the wild

Rust cories live in shallow, slow stretches and flooded margins of small tributaries across the upper Amazon, in western Brazil and Peru. The water is warm, soft and slightly acidic, and it runs over sand and leaf litter. Adults sift the top layer of sand for food during the day and gather in loose groups near cover.

Weekly picks

Tank mates

The rust cory is a peaceful, shoaling species that keeps to the bottom. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a rust cory need?

A rust cory needs at least 20 gal (75 L). It spends most of its time in the bottom.

What temperature and pH does a rust cory need?

A rust cory is comfortable at 72–79°F (22–26°C) with a pH of 5.5–7.2.

What does a rust cory eat?

A rust cory eats sinking pellets, frozen bloodworm and other small foods. Make sure the food reaches the bottom, where it forages.

How big does a rust cory get?

An adult rust cory reaches about 2.4 in (6 cm).

Does a rust cory need a group?

Yes. A rust cory is a shoaling species and should be kept in a group, not singly.

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