Back to 
Cnidaria 
Back to 
Animals
Back to Alphabetized Species List

Back to Completed Reports List

 

Species Name:    Oculina varicosa
Common Name:            (Ivory Tree Coral)

 

I.  TAXONOMY

Kingdom Phylum/Division: Class: Order: Family: Genus:
Animalia Cnidaria Anthozoa Scleractinia Oculinidae Oculina
  

Colony of Oculina varicosa.  Photo courtesy of:  J. Reed, Harbor Branch Oceanographic Institution.

Species Name: 
Oculina varicosa Lesueur, 1821

Common Name:
Ivory Tree Coral

 

 

 


Species Description:

In shallow waters (2 - 40 m), Oculina varicosa often occurs as a semi-isolated, low-growing colony, patchily distributed on coquinoid reef.  However, in deeper water (70 -100 m) it can occur as a massive, coalescing aggregate having substantial topographical relief.  Colors range from yellow-brown to lavender.  

Potentially Misidentified Species:
Oculina diffusa, Oculina arbuscula, Oculina valenciennesi


II.  HABITAT AND DISTRIBUTION 

Regional Occurrence:
Oculina varicosa occurs from the east Florida coast to North Carolina, Bermuda and the West Indies (Reed et al 1982).

IRL Distribution:
Oculina varicosa occurs sparsely in the Indian River Lagoon and on ledges in intracoastal waterways. O. varicosa occurs abundantly on shallow (6 m) near-shore reefs and on shelf edge banks (80 m) off east central Florida.


III. LIFE HISTORY AND POPULATION BIOLOGY

Age, Size, Lifespan:
Size range in Oculina varicosa found in shallow water is from 10 -  25 cm, with an average size of 15 cm.  Deep water specimens can range from 25 - 150 cm; with a typical size of 100 cm.  

Growth rates are apparently somewhat higher in deeper water than in shallow water.  Growth for this species at 6 m depth was 11.3 mm per year;  however, at 80 m depth, growth rate of Oculina varicosa was 16.1 mm per year.  Based on growth rates of 16 mm/yr, large colonies of Oculina varicosa could exceed 100 years of age.

Embryology:
Egg development time of Oculina varicosa in the laboratory is approximately 12 hours. The planula larva is most likely lecithotrophic and takes 18 - 22 days for development at 16 C, in the laboratory.


IV.  PHYSICAL TOLERANCES

Temperature:
Reef temperatures recorded for Oculina varicosa off Fort Pierce, Florida  ranged from 7 - 31 C and averaged 15 - 25 C. 

Salinity:
In the Indian River Lagoon, recorded salinities ranged from 15 - 36.5 ppt.  Off Fort Pierce, Florida, reef salinities for this species ranged from 28 - 36.4 ppt.


V.  COMMUNITY ECOLOGY

Trophic Mode:
O. varicosa feeds on plankton and tiny fish.  It may also suspension feed using mucous strands.

Habitat:
Oculina varicosa grows on low and medium relief limestone ledges (0.5 - 3.0 m) and on high relief shelf edge pinnacles (25 m relief). Benthic depth range for O. varicosa is 3.0 - 150.0 meters. Oculina varicosa can withstand moderate wave exposure on near-shore reefs (3.0 - 5.0 m deep). 


VI. SPECIAL STATUS

Special Status:
Habitat Structure

Benefit in the IRL:
Oculina varicosa provides habitat for a high diversity of invertebrates including crustaceans (Reed et al 1982) , mollusks (Reed & Mikkelsen 1987), fish, annelids and sipunculan worms.

Economic Importance:
Oculina varicosa provides nursery and habitat for commercially and recreationally important fish including grouper and snapper.

 

Report by:  J. Dineen, Smithsonian Marine Station
with thanks to J. Reed, HBOI
Submit additional information, photos or comments to:
irl_webmaster@si.edu
Page last updated: July 25,  2001