Gooseneck barnacles

Description:

Goose barnacles, also called stalked barnacles or gooseneck barnacles, are filter-feeding crustaceans that live attached to hard surfaces of rocks and flotsam in the ocean intertidal zone.

Habitat:

Cabrillo National Monument The park offers a superb view of San Diegos harbor and skyline. At the highest point of the park stands the Old Point Loma Lighthouse, which has been a San Diego icon since 1854. A statue and museum in the Visitor Center commemorate Juan Rodrguez Cabrillo's exploration of the coast of California. In a former army building an exhibit tells the story of the coast artillery on Point Loma. In the winter, migrating gray whales can be seen off the coast. The two-mile Bayside Trail affords spectacular views of San Diego Bay and the city beyond, and takes you through one of the last remaining remnants of coastal sage scrub habitat in the world. The rocky intertidal area is one of the best protected examples of these unique ecosystems in Southern California.

Notes:

Goose barnacles are marine crustaceans but, unlike many other members of their class, they are hermaphrodites, meaning that the animal has both male and female sexual organs. Their eggs hatch into free-swimming larvae, which drift with the ocean currents as one of the immense number of animals that comprise zooplankton. As they develop, the larvae attach themselves to an object by way of a strong stalk or 'peduncle'. Once they have attached themselves to an object, they do not move again unless torn off by accident. As they grow they develop a feathery feeding apparatus, which filters particles of food from the water as the current passes over it. This filter can be speedily withdrawn inside the hard capitulum when the barnacle feels threatened.