Azure Damselfish (Chrysiptera hemicyanea)

The Azure Damselfish, also known as the Half-Blue Damselfish or Azure Demoisselle, is one of the most popular and striking “starter” fish in the marine hobby. It features a brilliant, vibrant blue body with a contrasting bright yellow lower belly and tail. While many damselfish have a reputation for being overly aggressive, the Azure is considered one of the more “mellow” members of the family, making it a staple for both nano tanks and large reef displays.

Key Information

• Common Name: Azure Damselfish, Half-Blue Damselfish, Azure Demoisselle

• Scientific Name: Chrysiptera hemicyanea

• Origin: Indo-West Pacific (Indonesia to Australia)

• Max Size: 78 cm

• Lifespan: 510 years

• Temperament: Semi-aggressive (but peaceful for a damselfish)

• Diet: Omnivore accepts mysis shrimp, brine shrimp, algae, and high-quality flakes/pellets

• Care Level: Easy

Water Parameters

• Temperature: 2227C

• pH: 8.18.4

• Specific Gravity: 1.0201.025

• Minimum Tank Size: 75L (20 Gallons)

Behaviour & Tank Compatibility

The Azure Damselfish is prized for its hardiness and active swimming. It is a fantastic choice for cycling a tank (though fishless cycling is preferred) or adding movement to the rockwork.

• Aggression: Unlike the notorious Blue Devil Damselfish, the Azure is relatively peaceful. However, it is still territorial and will defend its favorite “home” cave from intruders.

• Social Structure: They can be kept singly or in small groups (3+) in larger tanks. In groups, they will establish a pecking order, which usually results in less aggression toward other species.

• Tank Mates: Compatible with a wide range of fish, including Tangs, Blennies, and larger Wrasses. Avoid keeping them with very timid species like Firefish unless the tank is large enough for everyone to have their own space.

• Reef Safe: 100% Reef Safe. They do not bother corals, clams, or invertebrates.

Ideal Tank Setup

• Rockwork: Provide plenty of live rock with small crevices and caves. This allows the fish to claim a territory, which significantly reduces its need to harass tank mates.

• Swimming Space: They are active and enjoy darting in and out of the water column, so ensure there is ample open space in the middle of the tank.

• Filtration: They are quite hardy, but like all marine fish, they thrive in well-oxygenated water with low nitrates.

Why Choose the Azure Damselfish?

The Azure Damselfish is the perfect “pop of color” for any reef. Its electric blue and yellow palette is one of the most iconic looks in the hobby. It is an exceptionally hardy and inexpensive fish, making it an ideal choice for beginners or for those looking to add a resilient, active inhabitant that won’t hide all day.