The Indian Damsel fish lives in the coral reefs of the Indo-Pacific from the surface to a depth of 15 meters. These fish live in groups that can even be numerous; they lead a mainly diurnal life and are quite easy to approach by snorkeling (as you can see from the video). They are territorial and very aggressive. The coloration of Pomacentrus indicus is typically dark and like all damselfish fish it belongs to the Pomacentridae family. Pomacentridae is a family of ray-finned fish, comprising the damselfishes and clownfishes. This family were formerly placed in the order Perciformes. They are primarily marine. Around 385 species are classified in this family, in about 31genera. The name of the family is derived from the Greek words; poma roughly translates to the English “cover”, referring to the fishes’ opercola, and kentron is Greek for sting. The name refers to the serrations found along the margins of the opercular bones in many members of this family. damigella indiana
Pomacentrids are found primarily in tropical seas, with a few species occurring in subtropical waters (e.g.Hypsypops rubicundus). Most species are found on or near coral reefs in the Indo-West Pacific (from East Africa to Polynesia). The area from the Philippines to Australia hosts the greatest concentration of species. The remaining species are found in the Atlantic or eastern Pacific. Some species are native to freshwater or brackish estuarine environments. Most members of the family live in shallow water, from 2 to 15 m. in depth, although some species (e.g.Chromis abyssus) are found below 100 m. Most species are specialists, living in specific parts of the reef, such as sandy lagoons, steep reef slopes, or areas exposed to strong wave action. In general, the coral is used as shelter, and many species can only survive in its presence. Pomacentrids have an orbiculate to elongated body shape, which is often laterally compressed. They have interrupted or incomplete lateral lines and they usually have a single nostril on each side (some species of Chromis and Dascyllus have two on each side. They have small- to medium-sized ctenoid scales. They have one or two rows of teeth, which may be conical or spatulate.
They display a wide range of colors, predominantly bright shades of yellow, red, orange, and blue, although some are a relatively drab brown, black, or grey. The young are often a different, brighter color than adults. Pomacentrids are omnivorous or herbivorous, feeding on algae, plankton, and small bottom-dwelling crustaceans, depending on their precise habitats. Only a small number of genera, such as Cheiloprion, eat the coral where they live. Before breeding, the males clear an area of algae and invertebrates to create a nest. The male swims behind the female as she lays the eggs, and fertilises them externally. Varying by species, brood sizes range from 50 to 1000 eggs.
The male guards the nest for the two to seven days needed for the eggs to hatch. The transparent larvae are 2 to 4 mm. long. They go through a pelagic stage, which depending on the species, can last as little as a week or more than a month. When they arrive at a suitable environment, the young settle and adopt their juvenile colors. In captivity, pomacentrids live up to 18 years, but they probably do not live longer than 10 to 12 years in the wild.
(extract from Wikipedia)