E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Halosydna brevisetosa Kinberg, 1855
Eighteen-Scaled Worm
Family: Polynoidae

Photo of species

© Derek Holzapfel  Email the photographer   (Photo ID #15654)

E-Fauna BC Static Map
Distribution of Halosydna brevisetosa in British Columbia
Details about map content are available here.


The scaleworm Halosydna brevisetosa is mostly free-living, although it is occasionally found with other invertebrates, such as within the tubes of tubeworms. The elytra in this species are diagnostic, that is, they are 18 in number, and always 18. The elytra are modified scales and may function in protection, or in providing a space within which seawater moves for gas exchange. Seawater is apparently driven through the space between the elytra and the dorsal skin by beating of cilia on the skin. There is an opinion that the fluid within the large body spaces of the worm moves in a counter-current direction to the seawater flow, thus creating optimal exchange of respiratory gases (oxygen and carbon dioxide). Halosydna has large jaws and is a predator on other bottom-dwelling invertebrates such as small crustaceans and worms. More on elytra function in Halosydna can be found in A SNAIL'S ODYSSEY: LEARN ABOUT SANDWORMS & RELATIVES: PHYSIOLOGICAL ECOLOGY

Note Author: Tom Carefoot, Department of Zoology, University of British Columbia.

Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Additional Photo Sources

General References

Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2024-05-23 3:52:09 PM]
Disclaimer: The information contained in an E-Fauna BC atlas pages is derived from expert sources as cited (with permission) in each section. This information is scientifically based.  E-Fauna BC also acts as a portal to other sites via deep links.  As always, users should refer to the original sources for complete information.  E-Fauna BC is not responsible for the accuracy or completeness of the original information.

© E-Fauna BC 2021: An initiative of the Spatial Data Lab, Department of Geography, UBC