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Cladonema radiatum
Image courtesy of the collection Georges Declercq, licensed under a CC BY-NC-SA 3.0 license.
Cladonema radiatum
Taxonomic Group: Cnidarians-Hydrozoans


The hydrozoan Cladonema radiatum has a conspicuous planktonic medusa stage and a small, creeping hydroid stage. It is native to European waters where it can be found from Norway to the Mediterranean and Black Seas. It has been reported from Bermuda, Florida, the Bahamas, Puerto Rico, Belize, and Brazil, but we consider it as being cryptogenic in the tropical Western Atlantic. Introduced populations have been reported from Padilla Bay, Washington; Oahu, Hawaii; and Wellington, New Zealand. It commonly settles on algae or seagrasses, such as the Mediterranean Posidonia oceanica or the temperate eelgrass Zostera marina. No impacts have been reported for this species.

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Fofonoff PW, Ruiz GM, Steves B, Simkanin C, & Carlton JT (2018)
National Exotic Marine and Estuarine Species Information System.
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