Common name: Blue Devil

General Information

The Blue Devil (Chrysiptera cyanea) is a vibrant and popular choice among marine aquarium enthusiasts. Known for its striking electric blue coloration, which varies depending on sex and maturity. Juveniles and females typically have an orange tail, while mature males have a blue tail that matches their body color. This small fish adds a splash of color to any aquarium setup. Despite its small size, the Blue Devil is known for its bold personality, often displaying territorial behavior, especially in smaller tanks.

In the wild, these fish are found in the Indo-Pacific region, inhabiting coral reefs and lagoons. They are often seen darting in and out of coral crevices, where they find shelter and food. Their energetic nature and dazzling appearance have made them a staple in the aquarium trade.

Care

Blue Devils are relatively easy to care for, making them suitable for both beginner and experienced aquarists. They thrive in well-established marine aquariums with plenty of live rock and hiding places. While they are hardy fish, maintaining stable water parameters is crucial for their health.

These fish do well in tanks with a minimum volume of 100 liters (about 26 gallons), but larger tanks are preferable as they provide more space for swimming and reduce territorial aggression. A tank with a variety of rock formations and coral structures will help mimic their natural habitat and provide them with necessary hiding spots.

Diet and Feeding

In the wild, Blue Devils feed on zooplankton and small invertebrates. In captivity, they should be offered a varied diet that includes high-quality marine flakes, pellets, and frozen foods such as brine shrimp and mysis shrimp. Feeding them small portions twice a day is recommended to keep them healthy and vibrant.

Behavior and Compatibility

Blue Devils are known for their semi-aggressive nature, particularly towards their own kind and other small fish. They establish territories and may become aggressive if they feel their space is threatened. However, in larger tanks with plenty of hiding spots, their aggression can be minimized.

They are generally compatible with other peaceful fish species but should be monitored when introduced to a community tank. Avoid housing them with overly aggressive or much larger fish that might intimidate them.

Reproduction

Breeding Blue Devils in captivity can be challenging but is possible. They are egg layers, and the male typically guards the eggs until they hatch. Providing flat surfaces in the tank can encourage spawning behavior. The fry are delicate and require special care, including feeding on rotifers and newly hatched brine shrimp.

Health and Common Issues

Blue Devils are hardy fish but can be susceptible to common marine diseases such as ich and marine velvet. Ensuring a clean tank environment and a balanced diet helps prevent these issues. Quarantine new additions to the tank to avoid introducing diseases.

Habitat

Blue Devils are native to the Indo-Pacific region, including the Great Barrier Reef, the Philippines, and Indonesia. They prefer warm, shallow reef environments with plenty of coral and rock structures to explore and establish territories.