Galapagos Species Database
The Galapagos Species Database shares the information about the species from our Natural History Collections.
Halopteris alternata
Hydroide, Hydroids
Domain
Eukaryota
Kingdom
Animalia
Phylum
Cnidaria
Class
Hydrozoa
Order
Leptothecata
Suborder
Conica
Family
Halopterididae
Genus
Halopteris
Species
alternata
Taxon category: Accepted
Syn.: Plumularia alternata Nutting, 1900 (Horton et al., 2021).
Origin: Introduced - established
Year of first record: 2016
Mode of introduction: Accidental
Introduction Pathway: Stowaway
Subpathway: Ship hull
Introduced status: Naturalized
Invasive status: Under watch
Map of specimen collection localities or observation records for this species in our collections database.
Distribution: (P. alternata Nutting, 1900) Mexico (Isabel I), Colombia, Panama and Ecuador in Santa Elena Bay and Galapagos Islands in Wolf I, Floreana (Black beach) (Calder et al., 2003; Fraser, 1938) Western Atlantic, eastern Atlantic, eastern Pacific, Tropical Eastern Pacific, Ecuador: Salinas, Galapagos Islands: Santa Cruz (Calder et al., 2021).
- Calder, D.R. Carlton, J. T., Keith, I., Larson, K., McCann, L., Geller, J., Wheelock, M., Choong, H. H. C., & Ruiz, G. M. (2021) Additions to the hydroids (Cnidaria, hydrozoa) of marine fouling communities on the mainland of ecuador and in the galapagos islands Aquatic Invasions, 16(2), 208–252. https://doi.org/10.3391/ai.2021.16.2.02
- Calder, D.R. Carlton, J. T., Larson, K., Mallinson, J. J., Choong, H. H. C., Keith, I., & Ruiz, G. M (2019) Hydroids (Cnidaria, Hydrozoa) from marine fouling assemblages in the Galápagos Islands, Ecuador Aquatic Invasions (2019) Volume 14, Issue 1: 21–58
- Calder, D.R. Mallinson, J.J., Collins, K. & Hickman, C.P. (2003) Additions to the Hydroids (Cnidaria) of the Galapagos, with a List of Species Reported from the Islands. J. Nat. Hist. 37:1173-1218.
- Carlton, J. T. Keith, I., & Ruiz, G. M. (2019) Assessing marine bioinvasions in the Galápagos islands: Implications for conservation biology and marine protected areas. Aquatic Invasions, 14(1), 1–20. https://doi.org/10.3391/ai.2019.14.1.01
- Fraser, C.M. (1939) Distribution of the hydroids in the collections of the Allan Hancock Expeditions. Fraser, M. (1939). Distribution of the hydroids in the collections of the Allan Hancock Expeditions. In Allan Hancock Pacific Expeditions. (Vol. 4, pp. 155–178).
- Horton, T. Horton, T., Kroh, A., Ahyong, S., Bailly, N., Boyko, C. B., Brandão, S. N., Gofas, S., Hooper, J. N. A., Hernandez, F., Holovachov, O., Mees, J., Molodtsova, T. N., Paulay, G., Decock, W., Dekeyzer, S., Poffyn, G., Vandepitte, L., Vanhoorne, B., Adlard, R., ... Zhao, Z. (2021) World Register of Marine Species. Available from https://www.marinespecies.org at VLIZ.
You are welcome to download and use the information found in this page, acknowledging its source.
This page should be cited as follows:
"Galapagos Species Database, Halopteris alternata", dataZone. Charles Darwin Foundation, https://datazone.darwinfoundation.org/en/checklist/?species=18866. Accessed 30 October 2026.