TankBud

Blue damsel

Chrysiptera cyanea

Also known as Blue Devil Damselfish, Blue Devil Damsel, Sapphire Devil

SaltwaterFish

Blue damsel (Chrysiptera cyanea)
Brian Gratwicke · CC BY 2.0

Care at a glance

Temperature
75–81°F
24–27°C
pH
8.1–8.4
Adult size
3.1 in
8 cm
Minimum tank
29 gal
110 L
Temperament
Aggressive
Social behavior
Social
Own kind
One male per tank
Tankmates
With caution
Swim level
Middle
Difficulty
Beginner
Breeding
Substrate spawner · Medium
Rarity
Very common
Reef safe
Reef safe
Family
Pomacentridae
Origin
Indo-Pacific

Overview

The blue damsel is extremely hardy and cheap, which is why it is everywhere in the hobby. It is easy to keep, but its temperament is a real problem.

Did you know

The blue damsel's toughness once made it the go-to fish for cycling new tanks. The practice is now discouraged, because the fish that survives the cycle is nearly impossible to catch out of the rockwork afterward.

Caring for the blue damsel

Give the blue damsel at least 29 gal (110 L) with plenty of rockwork and defined territories, so its aggression has somewhere to diffuse. Keep the water at 75 to 81°F (24 to 27°C) and a pH of 8.1 to 8.4. It accepts almost any prepared or frozen food. It is technically reef safe, since it ignores corals and inverts.

Males set up rigid territories and chase intruders relentlessly. Keep only one male per tank. A lone male will bully a peaceful community, so add it to the tank last. A group of five to seven in a tank of 55 gallons or more also spreads out the aggression.

Males and females differ in color, and males in many populations develop an orange tail and face. The blue damsel is a demersal spawner, and the male guards eggs laid on a cleaned rock surface. Breeding it is moderately hard.

Good to know

The blue damsel, Chrysiptera cyanea, is a damselfish in the family Pomacentridae. It is famous as one of the most aggressive small marine fish.

In the wild

The blue damsel is found across the tropical Indo-Pacific, over shallow lagoon and reef-flat habitats with plenty of rubble and coral. It sticks close to the bottom third of the reef, using cracks and coral heads as cover.

Common questions

What size tank does a blue damsel need?

A blue damsel needs at least 29 gal (110 L). It spends most of its time in the middle.

What temperature and pH does a blue damsel need?

A blue damsel is comfortable at 75–81°F (24–27°C) with a pH of 8.1–8.4.

What does a blue damsel eat?

A blue damsel accepts almost any prepared or frozen food.

How big does a blue damsel get?

An adult blue damsel reaches about 3.1 in (8 cm).

How can you tell a male blue damsel from a female?

Males and females differ in color. In many populations, males develop an orange tail and face.

How does a blue damsel breed?

Blue damsels are demersal spawners, and the male guards eggs laid on a cleaned rock surface. Breeding them is moderately hard.

Related species