Chrysiptera hemicyanea (Azure Damselfish / Azure Demoiselle / Half-Blue Damselfish)
• Small fish safe: ✅ Yes
• Small invert safe: ✅ Yes
• Coral safe: ✅ Yes
• Minimum tank size: 100L+ (preferably larger for multiple individuals)
• Adult size: ~7 cm (2.8 inches)
• Diet: Omnivorous (marine pellets, frozen mysis/brine shrimp, algae-based foods)
• Be aware of: Can become territorial and moderately aggressive, especially as they mature. Best kept singly or in small groups in larger tanks with ample hiding spots to disperse aggression. Juveniles are less aggressive, but adults may become dominant over other fish.
Azure Damselfish (Chrysiptera hemicyanea) – A Vibrant and Hardy Reef Fish
The Azure Damselfish, also known as the Azure Demoiselle or Half-Blue Damselfish, is a strikingly colored and resilient species popular among marine aquarists. Its brilliant blue and yellow coloration, coupled with its hardy nature, makes it an excellent choice for both beginners and experienced hobbyists.
Appearance and Coloration
The Azure Damselfish is characterized by:
• A vibrant blue upper body, extending from the head to the midsection.
• A bright yellow lower body and tail, creating a sharp contrast with the blue.
• A compact, oval-shaped body with rounded fins, contributing to its agile swimming style.
• A maximum length of approximately 7 cm (2.8 inches), making it suitable for a variety of tank sizes.
This striking coloration remains vivid throughout its life, adding a dynamic visual appeal to marine aquariums.
Natural Habitat and Behavior
Native to the eastern Indian Ocean and western Pacific, including regions such as Indonesia, the Philippines, and the Great Barrier Reef, Azure Damselfish are typically found in:
• Shallow lagoons and nearshore reefs, often associated with branching corals like Acropora.
• Depths ranging from 1 to 38 meters, though they are most commonly observed in shallower waters.
• Small groups or solitary, establishing territories within coral structures.
In the wild, they are known to be reef-dependent, relying on coral formations for shelter and protection.
Tank Requirements and Water Parameters
To ensure the well-being of Azure Damselfish in captivity:
• Minimum tank size: 100 liters (26 gallons) for a single specimen; larger tanks are recommended for multiple individuals to mitigate territorial behavior.
• Aquascape: Provide ample live rock formations to create hiding spots and establish territories, which can help reduce aggression.
• Water parameters:
• Temperature: 24–27°C (75–81°F)
• pH: 8.1–8.4
• Salinity: Specific gravity of 1.020–1.025
Maintaining stable water conditions with regular monitoring is essential for their health.
Diet and Feeding
Azure Damselfish are omnivorous and have a versatile diet:
• In the wild: They primarily feed on plankton and small invertebrates.
• In captivity: They readily accept a variety of foods, including:
• High-quality marine flakes and pellets (preferably vitamin-enriched)
• Frozen or live foods such as mysis shrimp and brine shrimp
• Algae-based foods to supplement their diet
Feeding once or twice daily with a varied diet will help maintain their vibrant coloration and overall health.
Compatibility and Tank Mates
While Azure Damselfish are generally less aggressive than some other damselfish species, they can still exhibit territorial behavior:
• Suitable tank mates: Other semi-aggressive species such as certain clownfish, wrasses, and tangs.
• Invertebrates: They are reef-safe and do not pose a threat to corals or most invertebrates.
Avoid housing with:
• Very passive or timid fish, which may be intimidated by the damselfish’s territorial nature.
• Other aggressive damselfish species, unless the tank is sufficiently large with plenty of hiding spots.
If keeping multiple Azure Damselfish, it’s advisable to introduce them simultaneously to minimize territorial disputes.
Breeding and Reproduction
Breeding Azure Damselfish in captivity is possible:
• Spawning: They are egg layers, with females depositing adhesive eggs onto substrates such as rocks or aquarium glass.
• Parental care: Males typically guard and aerate the eggs until they hatch.
Providing flat surfaces and maintaining excellent water quality can encourage breeding behavior.
Health and Disease Considerations
Azure Damselfish are hardy and resilient, but they can be susceptible to common marine diseases if stressed:
• Marine Ich (Cryptocaryon irritans): Can occur under poor water conditions or high stress