Gooseneck Barnacle
Pollicipes polymerus
Physical Description
- Crustacean with long, fleshy, flexible stalk permanently attached to hard surface.
- Stalk, or neck, ranges from reddish-brown to brownish-black in coloration.
- Many hard, pearlescent plates at top, protecting the body and internal organs.
- Tiny feathery feet, called cirri, project from plates, and are used to both feed and breathe.
- As they grow, they produce more plates.
Range
- From southern Alaska to Baja California, Mexico.
Habitat
- Found on rocky cliffs in the splash zone.
- Often in high-energy, high wave environments because their fleshy necks can survive it well.
- Often in crevices to avoid direct sunlight and limit drying out.
- Often in colonies of other gooseneck barnacles.
- Also found floating on marine debris in the open ocean.
Reproduction
- Gooseneck barnacles reach maturity around age 5.
- Although almost all other crustaceans have separate sexes, barnacles are hermaphrodites (each has both male and female organs).
- Will only self-fertilize if no other gooseneck barnacle within 8 inches.
- Since they are stationary, they have a very long, extendable penis (about seven times as long as their body diameter).
- Eggs are brooded in the mantle cavity.
- Newborn barnacles extend as one-eyed larvae that feed on plankton and molt several times until they look like miniature shrimp.
- When the planktonic larva settles out of the plankton, it crawls around to find other gooseneck barnacles before permanently settling. They must be near other barnacles for future reproduction.
Diet
- Filter-feeders.
- Eat plankton, cypris larvae, small clams, hydroids, and amphipods.
Predators
- Glaucous-winged gulls, sea stars, whelks.
- Humans eat as a delicacy.
Interesting Facts
- These are such a delicacy in Spain and Portugal, where they are often steamed and then dipped in hot, melted butter, that they can go for 100 Euros per plate!
- Though their long stalk looks like a goose’s neck, their name actually comes from a medieval belief that this is where baby geese actually hatched from!
- One of the most common organisms found on floating marine debris, their length can be used to give a minimum amount of time the item has been floating out at sea, as their length is proportional to their age.
Sources: AtlasObscura; Cabrillo Marine Aquarium; AnimalDiversity.org; animals.net
Photo: Kevin Lee