The dusky damselfish (scientific name: Stegastes adustus) is a member of the damselfish family (Family Pomacentridae) that lives on coral reefs in the Western Atlantic Ocean and the Caribbean Sea.

Dusky damselfish. Source: Florent Charpin/www.reefguide.org

Scientific Classification Kingdom: Animalia (Animals) Phylum:--- Chordata Class:------ Osteichthyes (Bony Fishes) Order:-------- Perciformes Family:-------- Pomacentridaedae (Damselfishes) Genus:----------Stegastes Species:--------- Stegastes adustus (Troschel, 1865)

Physical Description

Adult dusky damselfish are small (7.5 to 15.0 centimeters) oval fishes with dark coloration and rounded tails and dorsal fins. Juveniles are dark colored with a flash of bright orange from the head to the midpoint of their dorsal fin.

Distribution

The species is found in the Western Central Atlantic including Florida, the Bahamas, the Gulf of Mexico, the Caribbean Sea,  and along the coast of Central America to Panama and Venezuela.

Habitat

They live associated with coral reefs at depths ranging from one to 33 meters. They prefer to live in areas covered with rubble and are especially common inside thickets of Elkhorn coral.

Feeding Behavior

 Dusky damselfish are herbivores that feed on algae growing in their territories.

Behavior

Males and females defend small feeding territories.

Reproduction

Spawning occurs year round and females may spawn several times each month. At dawn, females go to nest sites inside a male’s territory where she will lay her eggs. A single nest may contain up to four clutches of eggs that are cared for and defended by the male.  Eggs hatch at sunset four days later and the larvae enter the pelagic stage where they remain for about three weeks.

Associations

Yellowtail damselfish commonly live in stands of elkbhorn coral along with dusky damselfish. Because yellowtail damselfish are so much larger, dusky damselfish usually come out on the losing end of competitive interactions between these two species.

Conservation Status

This species is not considered to be a species at risk.

References and Further Reading

• Encyclopedia of Life. 2011. Stegastes adustus (Troschel, 1865)
• Dusky damselfish Stegastes adustus  http://www.dosits.org/gallery/fishnbay/12.htm
• P.Humann and N.Deloach (Editors), 1994. Reef Fish Identification: Florida, Caribbean, Bahamas. New World Publications, Inc. Jacksonville, FL. ISBN: 1878348078
• N.Deloach. 1999. Reef Fish Behavior, Florida, Caribbean, Bahamas. New World Publications, Inc. Jacksonville, FL. ISBN: 1878348280