Thursday, February 5, 2009
Acorn Barnacle (Balanus)
Barnacles are common along the shores of British Columbia, encrusting intertidal rocks, pilings, wharves, ships, animals, and any other hard surface along the coast.
There are approximately twenty-one species of barnacles living on the coasts of British Columbia, of which there are two very different forms. There is the acorn barnacle, which has a hard, grey cone-shaped shell that is attached directly to a solid structure. These barnacles are well-known to anyone who has attempted to cross a rocky beach in bare feet. Acorn barnacles are able to close their shell, which protects them against drying out when the tide recedes.
The other form is the Gooseneck barnacle, whose shell-encased body is located at the end of a flexible stalk, which is attached to rocks or other solid structures. Barnacles play an important role in the marine environment as part of the food web, and empty barnacle shells provide shelter for other intertidal organisms.
Photo by Scott Stevenson. We have more information on Scott's photography on our web site >