Endangered Staghorn and Elkhorn Corals
Genus Acropora contains three Atlantic/Caribbean species, all currently listed as threatened under the Endangered Species Act. Acropora is found in the Florida Keys, Bahamas, Caribbean and the western portion of the Gulf of Mexico. The northern limit for Staghorn coral is around Boca Raton in Palm Beach County, and for Elkhorn coral, Biscayne Bay in Broward County.
Acropora is a relatively fast growing coral (2-4 inches annually) but is highly susceptible to damage caused by storm and surge activity. Once the dominant form of coral throughout Florida and the Caribbean, Acropora has declined in most areas by as much as 90-95%. The primary cause for this loss has been disease outbreaks, hurricanes, predation, bleaching, temperatures increases and sedimentation.
The numerous interlaced branching growth patterns of Acropora historically formed large reef structures which protected the high energy ocean side or "front" of reef zones and provided critical habitat for fish and invertebrates. Most Acropora reefs have now been reduced to barren rubble fields with a corresponding loss in habitat for other species.
Staghorn coral
Acropora cervicornis
Staghorn corals, as with all members of the subclass Zoantharia, have tentacles in multiples of three. During daylight hours the coral animal lies dormant and retracted into its stony coral caylyx. At night the fingerlike tentacles pump themselves up with water and pop out across the entire coral structure to feed. Staghorn corals use stinging nematocysts located on their tentacles to subdue and capture prey.
Staghorn corals derive their name from their appearance which is reminiscent of the multiple pointed antlers of male deer, or stag.
Elkhorn Coral
Acropora palmata
Elkhorn corals have a relatively more massive structure than Staghorn corals but are also susceptible to the same threats. The growth pattern is similar in appearance to antlers of elk. Often, Elkhorn coral will have a yellow to yellowish-brown coloration due to the presence of a symbiotic zooanthellae which lives within the cells of the coral animal. Elkhorn coral grows in the heavy surf areas of reef structures usually in 20 feet of water or less and may form dense "thickets" of structures which provide habitat for fish and invertebrates.
Report sightings of staghorn and elkhorn corals in Broward and Palm Beach County to the FAU DSO via email ehs@fau.edu or fax 561-297-2210, or directly to interested agencies by following the links below.
