The rock beauty (scientific name: Holacanthus tricolor) is a member of the angelfish family (Family Pomacanthidae) that lives among coral reefs in the tropical Western Atlantic Ocean and the Caribbean Sea.

Rock beauty. Source: ''Reef Fish Identification'', New World Publications © 1994.

Scientific Classification Kingdom: Animalia (Animals) Phylum:--- Chordata Class:------ Osteichthyes (Bony Fishes) Order:-------- Perciformes Family:-------- Pomacanthidae (Angelfishes) Genus:----------Holacanthus Species:----------- Holacanthus tricolor (Bloch, 1795)

Physical Description

Adult rock beauties range from 12.5 to 35.0 centimeters in length.  Their flattened, oval bodies have yellow on the front and the tail with black on their midbody.  Juveniles are bright yellow with a black spot ringed in blue.

Distribution

This species a tropical distribution (36°N - 7°S; 86°W - 34°W).  In the Western Atlantic they are found from Georgia (USA), Bermuda, and northern Gulf of Mexico to Santa Catarina, Brazil as well as in the Caribbean Sea.

Habitat

They live on coral reefs at depth ranging from three to 92 meters, but are most commonly found between three and 35 meters.  Juveniles often live with fire corals. 

Feeding Behavior

Rock beauties feed on sponges (about 95% of their diet) and algae (about four percent of their diet), as well as small invertebrates and eggs. Angelfishes have adaptations to allow them to feed on sponges.  Their strong mouths allow them to tear off pieces of sponges and they secrete mucous around their food to protect their stomachs from the spiny spicules of sponges.

Behavior

Males defend large territories (approximately 100 square meters) that contain the territories of several females. The males move through their territories throughout the day and they may occasionally feed with a female. They spend much of their day hiding in protected sites.

Reproduction

Rock beauties are protogynous hermaphrodites, so they change sex from female to male.  They start to reproduce as females when they are about nine centimeters in size and they change sex to when they reach about 12.5 centimeters.  Males mate with three or four females living in his harem.  Spawning occurs just before sunset in established spawning sites near coral mounds or gorgonians.  Spawning occurs in the water column and males often can mate with several female each night.  After the eggs hatch less than one day later for, the larvae enter the pelagic stage for three to four weeks until they settle.  The juveniles are very territorial but they do not set up cleaning stations but instead feed on planktonic animals and minute invertebrates.

Conservation Status

The rock beauty is considered to be a species at risk.

References and Further Reading

• Holacanthus tricolor (Bloch, 1795)
• Rock Beauty, Florida Museum of Natural History, University of Florida
  
• Humann, P. and N. Deloach (Editor), 1994. Reef Fish Identification: Florida, Caribbean, Bahamas. New World Publications, Inc. Jacksonville, FL. ISBN: 1878348078
• Deloach, N. 1999. Reef Fish Behavior, Florida, Caribbean, Bahamas. New World Publications, Inc. Jacksonville, FL. ISBN: 1878348280