Occulina diffusa generally forms dense colonies
up to 12 inches in diameter on short, crooked branches. Color is often a
yellow-brown, but this feature can be obscured by other organisms which encrust
the coral. This species prefers shallow areas high in sedimentation, to
depths of 3 - 75 feet, though it rarely occurs below 40 feet.
II. HABITAT AND
Oculina diffusa occurs in
Florida, Bermuda, the Bahamas and the West Indies.
While it does occur within the Indian River Lagoon, O. diffusa is
found primarily on nearshore reefs off east central Florida.
III. LIFE HISTORY AND POPULATION BIOLOGY
Age, Size, Lifespan:
Colonies grow to approximately 1 foot in diameter, with branches generally
less than 1/2 inch in diameter.
Oculina diffusa is common in nearshore reefs off Florida, though it
can be found within the Indian River Lagoon, especially around inlet areas.
Single polyps which have been sexually produced settle and attach to a
substratum where they bud asexually to give rise to entire colonies.
IV. PHYSICAL TOLERANCES
Reef temperatures recorded for Oculina diffusa off Fort Pierce, Florida
ranged from 13 - 31 °C and averaged 24.6 °C.
Salinities recorded for Oculina diffusa off Ft. Pierce, Florida
ranged from 26 - 36.4 ppt. In the Indian River Lagoon, salinities for O.
diffusa may be as low as 15 ppt.
V. COMMUNITY ECOLOGY
O. diffusa feeds on plankton and tiny fish; it may also
suspension feed to a smaller extent using mucous films to trap fine particles.
Oculina diffusa can be found on nearshore limestone ledges of 0.5 -
2.0 m relief. It is also found in the Indian River Lagoon and the
Intracoastal Waterway, Typically, it is found at depths of 2 - 3 meters,
up to 10 - 20 meters.
VI. SPECIAL STATUS
Notes on Special Status:
O. diffusa colonies provide habitat for a variety of invertebrates
and fish species.
Benefit in the IRL:
Oculina diffusa has a positive economic impact in the Indian River
Lagoon by providing habitat for commercially and recreationally important fish
and crustaceans, as well as some mollusks and annelids.
Report by: J. Dineen,
Smithsonian Marine Station
with thanks to J. Reed, HBOI
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Page last updated: July 25, 2001