Length - 10 centimeters
Diet - The Blue Chromis feeds on many small organisms present in the water that include phytoplankton, zooplankton, algae, and copepods (group of small crustaceans found in the seas and nearly every freshwater habitat).
Habitat - Blue Chromis are found in tropical water. They range from the East Indian Ocean to the Western Pacific, as well as the seas surrounding Malaysia and Indonesia, and thrive the most in waters that have a temperature between 72 and 78 degrees fahrenheit. They live in an average depth of 10-12 meters or 33-39 feet.
Dangers/Defense - This fish does have predators in the wild, and should never be put into a tank with Groupers, Lionfish, and eels. These are all natural predators and pose a danger. In the wild Blue Chromis stay in large schools in order to confuse predators, and are small enough to hide in coral in order to escape. On the other hand the Blue Chromis gets along well with any other tank mate that is peaceful or semi-aggressive.
Lifespan - Blue/Green Chromis can live anywhere between 8 - 15 years.
Reproduction - The male prepares the nest which is shared with several females. The nest is located on sand or rubble. During spawning, the male turns more yellowish in color. The large number of eggs will hatch in 2-3 days. The male guards the nest and ventilates it with its fins and feeding on those eggs that do not hatch in order to prevent them from being breeding grounds of microorganisms which risk the lives of the young.
Behavior/Temperament - Blue/Green Chromis are very territorial, live in schools from a about 7 to almost 100, but are fairly peaceful compared to other damselfish that defend their homes and food sources fiercely. However, it does not lack competitiveness in a self-created hierarchy within the school. This hierarchy is created by males, who are competing for females to mate with during the breeding season.
Symbiotic Relationships - Blue Chromis have a relationship with Acropora coral. The fish rids the coral of a variety of pests, and the coral provides a home and protection from predators.
A Closer Look At Growth and Development
- Unlike most damselfish, Blue/Green Chromis larvae are underdeveloped when they hatch. They lack pigmented eyes, and a functional mouth and gut. The larvae are about 2 mm long when they hatch, and subsist on protein and lipid rich yolk reserves.
- The larvae are ready to feed 2 days after hatching, and must be supplied with copepod larvae in order to survive. Chromis larvae may be highly selective in choosing their zooplankton prey, and because of this, this stage has the highest level of mortality.
- Between days 10 - 15, the larvae require constantly larger copepod prey. At this stage, the larvae undergo dramatic changes in the reorganization of the gut.
- Metamorphosis continues at a slower pace from this point. By day 35 the tiny juveniles measure 10 - 12mm, and display schooling behavior. The characteristic blue-green range of color in all members of the species is evident by day 40.
Blue Chromis are not endangered, do not pose a threat to humans, and are very common throughout their geographical range, however, there is a high mortality rate in moving the fish from the wild into aquariums and stores, because the fish do not adjust well to long periods of transportation. This is a very popular fish to have since it is very active, and therefore it is constantly in demand.
The Blue/Green Chromis has a unique bodily function that allows it to secrete a type of mucus, or slime, from their skin. This slime provides protection against parasites and infections and helps the fish move through the water faster and easier in order to outmaneuver predators.