TankBud

Dwarf cory

Gastrodermus hastatus

Also known as Corydoras hastatus, Black Diamond Cory

FreshwaterFish

Dwarf cory (Gastrodermus hastatus)
AquariaNR · CC BY-SA 3.0 de

Care at a glance

Temperature
68–79°F
20–26°C
pH
6.0–7.5
Adult size
1.3 in
3.2 cm
Minimum tank
10 gal
38 L
Temperament
Peaceful
Social behavior
Schooling
Swim level
Bottom
Difficulty
Easy
Breeding
Egg scatterer · Hard
Rarity
Rare
Family
Callichthyidae
Origin
Bolivia, Argentina, Paraguay

Overview

The dwarf cory is one of the smallest corys, a peaceful schooling fish for a planted community tank. It is easy to keep.

Did you know

Dwarf cories often shoal alongside other small fish such as tetras, joining a mixed group for safety rather than sticking to their own kind. In the wild they have been seen mixed in with much larger schools, using numbers as cover.

Caring for the dwarf cory

Keep dwarf cories in a group of at least six, and more is better, since they school tightly. A tank of 10 gal (38 L) or larger works. Plant it well but leave open swimming room, because this species spends more time off the bottom than most cories.

Use sand or fine, smooth gravel. They dig and sift with their barbels, and sharp grit wears those down. They prefer cooler water, at 68 to 79°F (20 to 26°C), with a pH of 6.0 to 7.5.

Feed sinking pellets and wafers, with the occasional frozen or live brine shrimp and bloodworms. Unlike typical bottom-sitting cories, they often hover and swim in midwater like tiny tetras.

Dwarf cories are peaceful and small, so pair them only with calm, similarly tiny tank mates. They scatter their eggs onto plants and surfaces, and breeding them in a home tank is tricky.

Good to know

The dwarf cory is an armored catfish in the family Callichthyidae, with bony plates covering its body instead of scales. It is listed as Gastrodermus hastatus and also known as Corydoras hastatus.

In the wild

Dwarf corys live in slow, shallow waters across Bolivia, Argentina and Paraguay. They favor spots thick with plants, over soft, sandy or silty bottoms.

Weekly picks

Tank mates

The dwarf cory is a peaceful, schooling 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 dwarf cory need?

A dwarf cory needs at least 10 gal (38 L). It spends most of its time in the bottom.

What temperature and pH does a dwarf cory need?

A dwarf cory is comfortable at 68–79°F (20–26°C) with a pH of 6.0–7.5.

What does a dwarf cory eat?

A dwarf cory eats sinking pellets and wafers, with the occasional frozen or live brine shrimp and bloodworms.

How big does a dwarf cory get?

An adult dwarf cory reaches about 1.3 in (3.2 cm).

Does a dwarf cory need a group?

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

How does a dwarf cory breed?

Dwarf cories scatter their eggs onto plants and other surfaces. Breeding them in a home tank is tricky.

Related species