Chromis viridis – Blue Green Damselfish
Green Chromis Damselfish (Chromis viridis) belong to the family Pomacentridae. This family is comprised of approximately 360 individual species in 28 genera. It includes all clownfish and damselfish. Chromis is but a single genus within this family. The collective name damselfish describes a group of fish that spans more than one genus. However, most damselfish fall within the genus chromis.
This species was first described in 1830 by Cuvier.
Green chromis are indigenous to the coral reef systems of the Indo-Pacific. Although they are a marine species, they often inhabit the brackish water from lagoons and inshore reefs. Several closely related and remarkably similar looking species can be found in the Caribbean Sea and among the Florida Keys.
This species has slender elongated, oval bodies with an iridescent sheen. Not all green chromis are actually green. There are three color variations; pale green, apple green, and pale blue. Regardless of color, they all have a mesmerizing shimmer to them as they swim about under aquarium lighting. This fish is commonly sold by the aquarium industry under the titles blue green chromis, green apple chromis and green chromis damselfish. They can grow to a maximum length of 4.5 inches. In an aquarium they rarely exceed 2-2.5 inches.
Many damselfish species take territorialism to the extreme. The green chromis is not among them. Neither does it become more aggressive as it matures. This is one of the mellowest, most peace loving fish of its entire family.
In the wild they live in schools amidst branchy stony corals such as acropora coral at depths of no more than 12-15 feet. This innate schooling instinct remains intact in the confines of an aquarium. They do not quarrel amongst themselves but rather feel more secure with like numbers in new surroundings. They will not tend to be as shy or skittish if kept in groups of no less than three. And a school of them looks exquisite in a well lit aquarium.
The Chromis viridis Aquarium
Green chromis make excellent additions to a community tank provided their tank mates are of smaller varieties and equally docile. They are very hardy and easy to maintain. Green chromis are excellent choices for amateur aquarists. This species works equally well in marine reef tanks as it does in fish-only aquariums. A school of three or four can be kept in as little as 10 gallons of water. Of course in a multi-species environment you will require a larger tank. In their natural environment they will retreat back into the protection of the coral branches they inhabit at the first sign of danger. They sleep under the shelter of these branches at night. In an aquarium they will require plenty of hiding places. They are quite active swimmers and will spend most of their time in the upper to mid-levels of an aquarium during the day.
These fish are planktonic omnivores. They are not picky eaters in captivity. You should not meet with any resistance getting them to feed. A good assortment of live rock will make them feel right at home. In nature, they often maintain algae farms by ridding rock formations of undesirable algae species. If they do not readily accept non-living offerings brine shrimp should entice them to begin eating. This can be mixed with larger and larger proportions of flake or freeze dried food until they become accustomed to aquarium fare. Their diet should contain protein, plant and algae matter. A good brand of fish food formulated for omnivores may very well be all that they need. Naturally, a supplement of dried algae sheets and fresh chopped sea food will help insure a well balanced diet. Under proper living conditions this species may live in excess of 15 years.
John de Lange