Chromis viridis(CUVIER 1830)
Type Locality: Red Sea: Massawa, Eritrea
Range: Widespread in the Indo-Pacific, Red Sea to the Line, Marquesan, and Tuamotu Islands, north to the Ryukyu Islands, south to New Caledonia
Taxonomic Troubles: Originally described as Pomacentrus viridis. You may also find it listed erroneously as Chromis caerulea, Dascyllus cyanurus, Glyphisodon bandanensis, Heliases frenatus, and Heliases lepisurus.
Size: 8 cm (a bit over 3 inches).
Preferred Water Chemistry: Tropical and subtropical marine.
Difficulty: An extremely hardy species and an extremely peaceful damsel. Excellent for beginners and experts alike. Reef-safe and safe to keep as multiple specimens in one aquarium.
Tank Setup: In the wild, large schools of this fish stay close to Acropora coral colonies. Although they will spend most of their time swimming out in the open, they appreciate a warren of hiding places in live rock. Combine with similarly peaceful fishes.
Feeding: Feeds on phytoplankton in the wild, but accepts all foods in captivity. Make sure to feed a diet high in algae products. Like all planktonivores, this species thrives when provided many small feedings throughout the day.
Breeding: This fish spawns in nests on the substrate. Several females may deposit eggs in a single male’s nest. The nesting male turns yellow and fans the eggs with his tail until they hatch. Larvae are planktonic.
Description: The panoply of common names for this fish that contain “blue” and/or “green” attests to its beautiful, changeable iridescent color, which flashes from light green to light blue as it moves, catching the light at slightly different angles.
Notes: Beautiful, hardy, fairly small, widely available, and inexpensive…what more can you ask for in a reef fish? This species easily answers that question with its peaceful, schooling nature. Unlike most feisty-to-murderous damselfishes, and unlike many reef fish that form huge aggregations in the wild but absolutely will not tolerate conspecifics in the aquarium, this damsel can be kept in small or large schools; however, in extremely small (nano) setups a single chromis only is recommended. This fish is peaceful with almost any tankmate. The accompanying photo of a group of these curious and playful fish that will encircle a friendly visiting diver was taken off Heron Island, Australia.