Dosima fascicularis, A Pelagic Barnacle, Builds its Own Float

My first in-person encounter with buoy barnacles, Dosima fascicularis, came just a few days ago on March 26, 2016. People call them buoy barnacles or own-float goose barnacles. The names make sense because D. fascicularis can produce a foamy gas-filled float, alleviating the need to hitch-hike. The color, according to photos I’ve seen, varies from creamy pale blue to the impressive blue you see here.


This one washed ashore on a small piece of plastic. The float is a foamy cream-colored globe. The brown encrusting organisms are small Lepus, another pelagic barnacle.

Consulting California Academy of Sciences (CAS-INVERT), I found records from northern  California, southern and northern Oregon, and the central Washington coast. Like a lot of ocean floaters, they have a worldwide tropical and temperate distribution.

There isn’t much natural history information available about Dosima fascicularis, but if you want to learn a more, I enjoyed reading Jackie Sones’ post on buoy barnacles. Jackie’s got a great blog, The Natural History of Bodega Head. It is a pure wealth of natural history and photography. I’ve learned a lot from those pages.

I was lucky to find my blue goose (yet another common name) because it was cast ashore amidst a mass stranding of Velella velella, which are also blue.

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Buoy amid a stranding of tiny by-the-wind sailors, Velella velella (March 26, 2016)

Ocean floaters are frequently blue and the similarity of these two is remarkable.

March 26, 2016 also saw lots of human-made floats wash ashore, including some blue buoys!

One of the more common blue floats found on Oregon beaches

If you want to see the variety of floats I discovered, click on my Wrack Line 2016 page.


Gonzalez, S., F. Scarabino, L. Ortega, A. Martinez, G. Fabiano, M. Abreu, P. Miller, A. Le Bas, R. Gonzalez de Baccino, M. Demicheli, and F. B. Pitombo. 2014. Dosima fascicularis (Cirripedia: Lepadidae) in Uruguayan waters: the southernmost western Atlantic presence of the ‘blue goose barnacle’. Marine Biodiversity Records, vol. 7; e99: 1-8

Kozloff, E. N. 1993. Seashore Life of the Northern Pacific Coast. 3rd ed. University of Washington Press.

Lamb, A. and B. P. Hanby. 2005. Marine Life of the Pacific Northwest. Harbour Publishing.

Light, S. F. 2007. The Light & Smith Manual: Intertidal Invertebrates from Central California to Oregon. 4th ed., edited by J. T. Carlton. University of California Press.


    1. That’s a beautiful Janthina photo June. A predator floating on the high seas’ surface film! Thank you for sharing it with me. March is here; I’ll be on the lookout! Thanks for the kind words.

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