Blue Reef Chromis

Blue Reef Chromis

The Blue Reef Chromis (Azurina cyanea, formerly Chromis cyanea) is one of the Caribbean's most dazzling small fish — an electric, almost luminous blue body, often edged in black along the back and fins. Active and hardy, it hovers in the open water above the reef and brings an intense flash of colour to a marine aquarium, especially when several are kept together.

A peaceful, undemanding planktivore, it is a fine choice for a community reef and a good introduction to keeping Atlantic species.

Natural Habitat & Origin

Azurina cyanea is found in the western Atlantic, around Bermuda, southern Florida and throughout the Caribbean Sea. It lives on coral reefs, hovering in loose groups in the water column above the reef to feed on plankton, and staying close to the structure into which it darts when threatened. It is most common in shallow reef zones but ranges deeper.

In the aquarium it appreciates open swimming space above the rockwork, with crevices and branching structure for shelter.

Care Requirements

Maintain stable marine conditions: salinity around 1.024–1.026, pH 8.1–8.4, and a temperature of about 24–26°C (75–79°F). Reaching about 13 cm (5 inches) and best kept singly or in a small group, it suits a tank of around 115 litres (30 US gallons) or more with open water to swim. It is hardy and adaptable, tolerating typical reef conditions well.

Diet & Feeding

The Blue Reef Chromis is an omnivore that feeds primarily on zooplankton in the wild, with some algae. It readily accepts aquarium foods: offer frozen mysis and brine shrimp, quality marine flakes and small pellets, and foods with marine algae content. Feed small amounts a couple of times a day; it is an eager, easy feeder.

Behavior & Temperament

This is a peaceful, somewhat loosely social fish — seen alone or in small groups in the wild rather than tight shoals. Kept in a small group it spreads out any minor squabbling and looks its best. It poses no threat to other tankmates and spends its time feeding in open water and sheltering near the reef.

Tank Mates

Good companions are other peaceful reef fish — clownfish, other chromis, gobies, smaller wrasses, cardinalfish and anthias. Avoid large aggressive species. It is fully reef-safe, leaving corals and invertebrates alone, making it an attractive, easy addition to a peaceful community reef.

Breeding

Like other damselfish, A. cyanea lays demersal eggs guarded by the male, but rearing the pelagic larvae is rarely accomplished in the home aquarium. Trade specimens are wild-collected.

Common Health Issues

The Blue Reef Chromis is hardy but, like all marine fish, can be affected by marine ich (Cryptocaryon irritans) and marine velvet (Amyloodinium ocellatum) under stress. Quarantine new arrivals, keep water quality stable, and provide shelter and open swimming space. Given those basics it is a brilliantly coloured, beginner-friendly and dependable addition to a peaceful reef.