Green chromis

The green chromis (Chromis viridis), also known as the blue-green chromis, is a small schooling fish that grows up to 10 cm in length. It has an oval-shaped body and a forked caudal fin. Its coloration ranges from bluish-green to bright green, shifting depending on the lighting conditions. These fish are well known for their iridescent hues, making them popular among aquarists.

In the wild, green chromis primarily feed on various types of plankton, including crustaceans (such as copepods and amphipods), shrimp larvae, fish eggs, and polychaetes. During the summer, their diet becomes more diverse, incorporating filamentous algae, phytoplankton, and zooplankton.

During the breeding season, males prepare a nest on sandy bottoms or among coral rubble, attracting multiple females. At this time, their coloration takes on a more yellowish hue. After spawning, the male guards the eggs, fanning them with his fins to improve aeration. He also consumes unfertilized eggs to prevent microbial growth that could harm the viable ones. In 2–3 days, the larvae hatch from the eggs.

These fish are widely distributed throughout the Indo-Pacific region, including the Red Sea. They inhabit coral reefs and lagoons at depths of 1 to 12 meters, forming large schools that can number in the hundreds. Green chromis prefer sublittoral lagoons and reef flats, often congregating above branching corals of the Acropora genus, which provide shelter and resting places at night.