What is it?
Coral reef scientists in the Caribbean recently released a paper cataloging the spread of a new invader in Venezuelan coral reefs: an Indo-Pacific gorgonian or octocoral. This species, categorized as Unomia stolonifera is within the family Xeniidae and is dominating coral reef habitats off the Venezuelan coast. Species within the Xeniidae family are known as “pulse corals,” known for their “pumping” movement in the water. These include the pom-pom variety (Xenia umbellata), a brown variety (Xenia elongata), and Silver-tip Xenia. This beauty and hardiness make them a popular aquarium species. In the wild, they require shallow water, lots of sunlight and wave action, and can even withstand nutrient-laden water.
Where has it been spotted?
Unomia stolonifera was introduced in Venezuela in the early 2000’s via illegal aquarium trade. These species can reproduce both sexually as well as asexually (or fragment), meaning that even small pieces can regenerate growth. A 2021 study indicates that in Venezuela, Unomia has spread from the East to the West of the country and in the Mochima National Park. This soft coral occupies approximately 50% of the native reefs, with coverage of up to 100% of the space in some areas. Since Venezuela is just to our south, there is certainly the potential for this species to make its way into our waters via currents or other transport mechanisms.
Why is this significant?
Members of the Xeniidae species dominate hard substrate, including stony corals and can even colonize on seagrass, including species that we have here in Florida (Turtle grass, Thalassia testinidum). In Venezuela, the Unomia species was observed overgrowing Thalassia, potentially limiting the seagrass’ ability to photosynthesize (Ruiz-Allais et al. 2021), as well as limiting native species’ ability to colonize and compete for food.
Similar to other exotic species, Xeniidae can take over in an aquarium. Unfortunately, species within this family are very hardy, making them difficult to remove from an aquarium environment. Therefore, implications of their spread within the ocean are quite serious, as colonization of these organisms could outcompete our native stony corals, soft corals, and seagrasses.
What can you do?
Do not release any aquarium species, exotic or invasive pets. Contact FWC’s Pet Amnesty Program to surrender or rehome your exotic pet.
If you are out snorkeling or diving and observe members of the invasive Xeniidae family on Florida reefs, early reporting is critical. If spotted, try to capture GPS coordinates and photographs and file a report at http://seafan.net.
Ruiz-Allais, J., Benayau, Y., Lasso-Alcalá, O. 2021. The invasive octocoral Unomia stolonifera (Alcyonacea, Xeniidae) is dominating the benthos in the Southeastern Caribbean Sea. Memoria de la Fundación La Salle de Ciencias Naturales. 79 (187): 63-80.