Xenia umbellata, taken by Diego Delso.
Be on the lookout! Invasive soft coral species found in the Caribbean
Multiple species of soft corals native to the Indo-Pacific have been found in Venezuela, Puerto Rico, and Cuba. Florida is on the alert in case these invasive species invade our waters. If seen, DO NOT TOUCH - these species are easily spread. Report all sightings to the USGS Nonindigenous Aquatic Species Sighting Report Form and read below to learn more.
Regulatory Status
Although not yet found in Florida, invasive soft corals are octocorals, and as such are not allowed to be removed without a permit. All octocorals, or soft corals, are protected in Florida following Marine Life Rule 68B-42.009. Careful consideration will be taken on how to best remove and responsibly authorize invasive soft coral removal without incidentally spreading them further.
Description
Unomia stolonifera in Cuba, taken by Jose Espinosa.
The invasive soft corals that have been found recently in the Caribbean are pulse corals. Multiple species have been documented, including Unomia stolonifera and Xenia umbellata. In general, pulse corals are:
- Stalked with branches ending in polyps
- Polyps have eight tentacles and very long
- Often have polyps growing directly out of stalk as well as from branches
- Greyish, greenish, and brownish in color, usually with paler stalks
- Polyps cannot retract - are always out and opening and closing, or "pulsing"
- Spicules are round or oval in shape
Individual pulse corals can be 2-10 inches tall. However, their ability to take over means "fields" of pulse corals can grow and cover acres of bottom habitat.
Pulse corals are benthic animals, meaning they attach themselves to the bottom of aquatic habitats and cannot move. They are found on coral reefs, hardbottom habitats, and seagrass beds. Their polyps constantly open and close to catch small plankton.
Pulse corals can reproduce both sexually and asexually through fragmentation. Their ability to grow and spread through fragmentation make it especially easy for them to take over an area. It also makes them difficult to safely remove without accidentally spreading them further. If seen, please DO NOT TOUCH for this reason.
Similar Species
Erythropodium caribaeorum, the encrusting gorgonian, is a native species that may be confused with invasive soft corals. However, the native encrusting gorgonian does not "pulse", the polyp tentacles are not feathery in appearance, and it is not stalked.
Florida has many native octocoral species, including branching octocorals like sea rods, sea plumes, sea fans, and encrusting octocorals. Branching octocoral species are erect, similar to pulse corals, and have main "stalks". However, native octocoral species have much narrower main stalks than pulse corals and have a harder texture. Native species also have a different branching structure than pulse corals, and much smaller polyps.
When invasive soft corals take over an area and grow in dense populations side by side, they can look similar to native encrusting octocorals like Briareum asbestinum or Erythropodium caribaeorum. Native encrusting octocorals do not have stalks, but in dense infestations of invasive soft corals the stalks can be hard to see. Native encrusting octocorals can retract their polyps, unlike the invasive pulse corals whose polyps are always out. Invasive soft coral polyps are also much larger and longer than native encrusting octocorals.
Diet
Pulse corals, like all other soft corals, are filter feeders. They catch small plankton and other marine life with their feathery tentacles.
Native Range
These invasive soft corals are native to Indo-Pacific waters. They have been verified as invasives in Venezuela, Puerto Rico, Cuba, and Hawaii. These invasive soft corals have not yet been observed in Florida waters.
Florida Distribution
Invasive soft corals have not yet been documented in Florida, but they have been seen in nearby waters and are common aquarium species. They are also referred to as "pulse corals", "pulsing Xenia", Xenia, or Unomia.
They were first reported as invasive species in the Caribbean in the early 2000's off the coast of Venezuela, where it is believed they were released intentionally for illegal aquaculture activities. They have since been documented in Hawaii in 2020, Cuba in February 2023, and Puerto Rico in October 2023.
Potential Impacts
Invasive soft corals grow rapidly and compete for space with native stony corals, octocorals, seagrasses, and other non-motile organisms that live on the seafloor. Spreading rapidly, they have even been documented to overtake and kill native stony corals.
Additional Information
Invasive pulse corals in Puerto Rico. Photo by Pichón Duarte.
Learn more about these invasive soft corals at The Unomia Learning Exchange.
Have you seen invasive soft corals in Florida? You can help by submitting reports of this invasive species. Your observations are important to help increase our understanding of these species and to promptly respond to an infestation. Please take photographs and record the latitude and longitude of your sighting.
Remember, invasive soft corals can spread through fragmentation. If you see one in Florida, please DO NOT TOUCH! It is easy to accidentally spread them if pieces break off the main colony.