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The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: white pulse coral

Synonyms and Other Names: pulse coral, pom pom Xenia

Identification: Xenia umbellata is a soft octocoral, which means that each individual polyp has eight tentacles (Fabricius and Alderslade 2001). Each polyp has 2–3 rows of feather-like pinnules giving the coral its pom pom-like appearance. The amount of pinnules in each row can vary from 16 to 27 (Halász et al. 2019). The stalks of this species can be both branched and unbranched (Reinicke 1997). The color of X. umbellata polyps is white to beige with the base of the colony being darker in color (Reinicke 1997; Halász et al. 2019). This species exhibits the distinctive pulsing behavior where the tentacles of the polyps expand and contract (Reinicke 1997; Halász et al. 2019).

Size: Individual polyps can reach up to 24 mm. The polyps bear tentacles that are 7–8 mm in length. Mature colonies can reach 90 mm in height (Reinicke 1997).

Native Range: Xenia umbellata is native to the Indo-Pacific region where it was first described from the Red Sea (Reinicke 1997).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology: Xenia umbellata is highly adaptable with the ability to colonize a variety of soft and hard substrates including rock, sand, scleractinian corals, sponges, and macroalgae (Hill et al. 2023; Toledo-Rodriguez et al. 2025). This species inhabits shallow water ranging from under 1 meter to 25 meters in depth (Hill et al. 2023). Xenia umbellata utilizes a mixotrophic feeding strategy where it can produce its energy photosynthetically or through suspension feeding. Unlike many other soft octocorals, this species can fulfill its energy needs through autotrophy alone (Mezger et al. 2022). In the absence of food, this species pulsates at a much lower rate than when food is present in the water column (Hill et al. 2023). This mixotrophic feeding strategy allows X. umbellata to persist in phosphate-enriched environments, in contrast to many stony coral species that typically decline under eutrophic or phosphate-enriched conditions (Vollstedt et al. 2020; Mezger et al. 2022). Additionally, X. umbellata has shown resistance to warming water temperatures—a major stressor to many stony coral species (Vollstedt et al. 2020; Mezger et al. 2022; Thobor et al. 2022).

Xenia umbellata can reproduce both sexually and asexually. In sexually reproductive colonies, fertilized eggs mature to their larval stage, known as planulae, inside a brood chamber located in the coenchyme structure between polyps (Benayahu 1991). While brooding, the planulae acquire algae symbionts from the parents before they are expelled from the brood pouch during spawning (Benayahu et al. 1988). The planulae can initiate metamorphosis one to two days after spawning but have a long competence period of up to 76 days during which metamorphosis remains possible. Xenia umbellata planulae exhibit remarkable longevity, surviving up to 155 days, and can persist even when displaying abnormal morphologies that develop during metamorphosis (Ben-David-Zaslow and Benayahu 1998). Xenia umbellata is capable of asexual reproduction through fragmentation and regeneration, whereby detached portions of the colony can settle, attach to substrate, and regenerate themselves (Kim et al. 2022; Nadir et al. 2023).

Means of Introduction: The exact means of introduction of this species is unknown. Plausible pathways for this species include the release of aquaria from captivity as this species is common in the aquarium trade and ballast water discharge due to its proximity to Port of Ponce, Puerto Rico (Toledo-Rodriguez et al. 2025).

Status: This species is currently established along the southwestern coast of Puerto Rico (Toledo-Rodriguez et al. 2025).

Impact of Introduction: In Puerto Rico, X. umbellata has been observed to overgrow on many other benthic organisms including macroalgae, stony corals such as Pseudodiploria strigosa and Colpophyllia natans, and sponges such as Xestospongia muta. This species has been observed to alter the benthic landscape composition by growing indiscriminately on a variety of substrates in the shallow reef systems that are not normally dominated by soft octocorals (Toledo-Rodriguez et al. 2025).

Remarks: Xenia umbellata has been suggested as a model soft coral for studying regeneration (Kim et al. 2022). Due to the ability to fragment and regenerate, hand removal could facilitate the spread of this species (Toledo-Rodriguez et al. 2025).

References: (click for full references)

Benayahu, Y., Y. Achituv, and T. Berner. 1988. Embryogenesis and acquisition of algal symbionts by planulae of Xenia umbellata (Octocorallia: Alcyonacea). Marine Biology 100: 93–101. https://doi.org/10.1007/BF00392959.
Benayahu, Y. 1991. Reprodution and developmental pathways of Red Sea Xeniidae (Octocorallia, Alcyonacea). Hydrobiologia 216: 125–130. https://doi.org/10.1007/BF00026452.
Ben-David-Zaslow, R. and Y. Benayahu. 1998. Competence and longevity in planulae of several species of soft corals. Marine Ecology Progress Series 163: 235–243. https://doi.org/10.3354/meps.
Fabricius, K. and P. Alderslade. 2001. Soft Corals and Sea Fans: A comprehensive guide to the tropical shallow-water genera of the Central-West Pacific, the Indian Ocean, and the Red Sea. Australian Institute of Marine Science. Townsville MC, Queensland, Australia.
Halász, A., C.S. McFadden, R. Toonen, and Y. Benayahu. 2019. Re-description of type material of Xenia Lamarck, 1816 (Octocorallia: Xeniidae). Zootaxa 4652(2): 201–239. https://doi.org/10.11646/zootaxa.4652.2.1.
Hill, C.E.L., S.G. Abbass, G. Caporale, Y.C. El-Khaled, L. Kuhn, T. Schlenzig, C. Wild, and A. Tilstra. 2023. Physiology of the widespread pulsating soft coral Xenia umbellata is affected by food sources, but not by water flow. Ecology and Evolution 13(9): e10483. https://doi.org/10.1002/ece3.10483.
Kim, S., C. Wild, and A. Tilstra. 2022. Effective asexual reproduction of a widespread soft coral: comparative assessment of four different fragmentation methods. PeerJ 10: e12589. https://doi.org/10.7717/peerj.12589.
Mezger, S.D., A. Klinke, A. Tilstra, Y.C. El-Khaled, B. Thobar, and C. Wild. 2022. The widely distributed soft coral Xenia umbellata exhibits high resistance against phosphate enrichment and temperature increase. Scientific Reports 12(1): 22135. https://doi.org/10.1038/s41598-022-26325-5.
Nadir, E., T. Lotan, and Y. Benayahu. 2023. Xenia umbellata (Octocorallia): A novel model organism for studying octocoral regeneration ability. Frontiers in Marine Science 10: 1021679. https://doi.org/10.3389/fmars.2023.1021679.
Reinicke, G.B. 1997. Xeniidae (Coelenterata: Octocorallia) of the Red Sea, with descriptions of six new species of Xenia. Fauna of Saudi Arabia 16: 5–62.
Thobor, B., A. Tilstra, D.G. Bourne, K. Springer, S.D. Mezger, U. Struck, F. Bockelman, L. Zimmermann, A.B.Y. Suárez, A. Klinke, and C. Wild. 2022. The pulsating soft coral Xenia umbellata shows high resistance to warming when nitrate concentrations are low. Scientific Reports 12: 16788. https://doi.org/10.1038/s41598-022-21110-w.
Toledo-Rodriguez, D.A., A.J. Veglia, N.M. Jimenez Marrero, J.M. Gomez-Samot, C.S. McFadden, E. Weil, and N.V. Schizas. 2025. Shadows over Caribbean reefs: occurrence of a new invasive soft coral species, Xenia umbellata, in southwest Puerto Rico. Coral Reefs 44: 1439–1444. https://doi.org/10.1007/s00338-025-02670-5.
Vollstedt, S., N. Xiang, S.M. Simancas-Giraldo, and C. Wild. 2020. Organic eutrophication increases resistance of the pulsating soft coral Xenia umbellata to warming. Aquatic Biology 8: e9182. https://doi.org/10.7717/peerj.9182.

Author: Stratton, L.D.

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.