Blue Chromis

Geographic Origin and Biotope: Endemic to the tropical Western Atlantic, common throughout the Caribbean, Florida, Bahamas, and the Gulf of Mexico. Hover in large schools above coral heads at depths of 3 to 60 meters.

Taxonomy and Morphology: Member of the Pomacentridae family. Features a compressed oval body and a deeply forked tail. Reaches a maximum size of 12 cm (4.7 inches).

Social Behavior: Active schooling fish. Should be kept in groups of 6 or more to encourage schooling behavior and prevent single individuals from becoming overly territorial or stressed.

Coloration and Sexual Dimorphism: Body is a solid, brilliant electric blue, with a dark black border outlining the dorsal ridge and the fork of the tail. No visible sexual dimorphism.

Aquarium Setup: Needs a tank of at least 150 liters with plenty of open swimming room and strong water movement to mimic reef conditions. Include live rock for nocturnal shelter.

Diet and Feeding: Planktivore/Omnivore. In captivity, feed a varied diet of frozen mysis, brine shrimp, high-quality flakes, and small pellets several times daily.

Water Quality: Prefers highly oxygenated water with good flow: temperature 24-27°C (75-81°F), pH 8.1-8.4, specific gravity 1.022-1.025, GH 15-25, and KH 8-12.

Compatibility and Tankmates: 100% reef-safe. Peaceful with other peaceful species. Avoid keeping with large predators or aggressive damselfish.

Aquarium Reproduction: Possible. Males clean a nesting site on rocks or sand and court females. The male guards the adhesive eggs until they hatch. Rearing fry is highly complex.

Risks and Diseases: Susceptible to the parasite Uronema marinum, which is common in chromis. Quarantine new arrivals carefully.