There are two types of barnacles. The first are those with their shells cemented directly to the substrate, such as the acorn barnacle I described in yesterday’s post (“Acorn Barnacle” on 12-07-2019). The second has a stalk between the substrate and the shell. Gooseneck barnacles (Pollicipes polymerus) are an example of stalked barnacles. Both types were growing in the tidepools at Endert’s Beach south of Crescent City CA (Del Norte County).
Like acorn barnacles, gooseneck barnacles are cemented to rocky and solid surfaces or into crevices of the intertidal zone along the Northeastern Pacific from Alaska to Baja. The attachment is via their antennae. Unlike acorn barnacles, gooseneck barnacles have a strong, rubbery stalk (the peduncle) between the point of attachment and the remainder of their body parts and shell (called the capitulum). The capitulum has five main calciferous plates or valves. Further centers of calcification on the capitulum produce additional small scales. The stalk retracts when the barnacle is touched or disturbed providing protection from predators.
Filter feeders, gooseneck barnacles grow outward and extend their cirri in a fan oriented perpendicular to the backwash of waves. Since gooseneck barnacles depend on water movement, not the movement of their cirri, for feeding, this orientation assists in food capture.
Also growing in crowded colonies, gooseneck barnacle reproduction is similar to that of acorn barnacles.
There are many myths to explain the common name. One is that Medieval naturalists, before they understood bird migration and realized that some birds nest elsewhere, thought stalked barnacles resembled goose eggs. They believed that goslings formed in the “goose egg”. When ready to hatch, the barnacle fell into the ocean and the fully formed goslings arose from the sea. The barnacle goose that nests in Arctic regions from Greenland to Siberia was one of the birds thought to form in barnacle “goose eggs”, hence the common name. Another myth states that the curved stalk looks like a goose’s neck and the capitulum resembles the goose’s head. So, early naturalists had vivid imaginations.
This crustacean is considered an edible delicacy. When cooked, the capitulum is held, the stalk sheath removed and then the stalk is dipped in butter and eaten. The stalks are also made into chowders and soups or incorporated into other dishes. Supposedly gooseneck barnacles taste like lobster or crab. I would like to try them some day.