Hydractinia altispina
{{Short description|Species of cnidarian}}
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| image = commensal hydroid7.jpg
| taxon = Hydractinia altispina
| authority = Millard, 1955
}}
Hydractinia altispina, or high-spined commensal hydroid, is a small colonial hydroid in the family Hydractiniidae.{{Cite web|title=WoRMS - World Register of Marine Species - Hydractinia altispina Millard, 1955|url=http://marinespecies.org/aphia.php?p=taxdetails&id=284838|access-date=2021-01-18|website=marinespecies.org}}
Description
High-spined commensal hydroids grow as a fuzzy-looking orange coat usually on the shell of a marine snail, the scaly dogwhelk Nucella squamosa. Individual polyps grow to 0.4 cm in total height. The polyps are naked and cluster on the shell surface, interspersed with defensive spines and tiny ball-like reproductive structures.Millard, N.A.H. 1975. Monograph on the Hydroida of Southern Africa. Ann. S. Afr. Mus. 68:1-513
Distribution
References
{{Commons category|Hydractinia altispina}}
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Category:Animals described in 1955
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