Chromis cyanea by Wikimedia Commons under CC 4.0

Geographic Location and Habitat

Chromis cyanea or Blue Chromis are located in the Western parts of the Atlantic Ocean including the Gulf of Mexico and the Caribbean Sea and are also found on the coast of Bermuda. They are most commonly seen swimming in reef habitats but can also be living in lagoons where food and shelter are prevalent. They are most commonly found swimming at depths of 10 meters to 20 meters. These fish rely greatly on the health of coral as they provide the Blue Chromis with a place to live, breed, feed and also protection from potential predators.


This oval-shaped reef fish is about 13 to 15cm in length once fully grown in their adult life stage. These fish get their name from their bright blue body color. They also have a black striped dorsal fin, anal fin, and caudal fin. One fun fact about Blue Chromis is that they have dark eyes which are a great way for people to distinguish this species among other similar ones.


These fish face several threats in their everyday life, some of which are not often touched upon by many people and they slide under the radar. One of the most serious threats is the Chromis trade. Large numbers of Blue Chromis are collected for use in aquaria. Damselfish or Blue Chromis make up a very large portion of the life we see in aquariums around the globe, almost half in most portions of the world. Another, possibly less serious threat is predation from lionfish which are growing in number every day. These invasive fish consume small damselfish and other reef fishes in the Caribbean and Atlantic oceans. Finally, another large and growing problem is the loss of coral which occurs in all oceans. The coral reefs are what provide the structure for the entire ecosystem which the Chromis thrive in and spend almost all of their lives.


The information in this chapter is thanks to content contributions from Devon Audibert


Icon for the Creative Commons Attribution-NonCommercial 4.0 International License

A Student's Guide to Tropical Marine Biology Copyright © by by Keene State College Students, BIO 381 Tropical Marine Biology is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.

Share This Book