Almost alien-looking, Stalked Tunicates (sometimes known as Sea Squirts) are often mistaken for a plant rather than an animal. They are somewhat difficult to classify biologically, because although considered an invertebrate they do possess a rudimentary dorsal nerve chord similar to a backbone in vertebrates. Two distinct parts of the tunicate can be easily identified: a cylindrical body and a thin trunk which anchors the animal to the rocks in subtidal areas. Tunicates have a leathery skin and can range in color from dark brown to bright orange.
At first glance, the animal may appear too fragile for an environment characterized by strong currents and pounding surf, but it is this constant flow of water which allows the animal to thrive. Sometimes referred to as “suspension feeders,” tunicates filter water through siphons at the end of their bodies and extract suspended particles of food.
Their natural predators include flatworms, sea stars, crabs, birds, fish, and sea otters. They are also eaten by humans in many parts of the world, including Asia, Europe and South America.
Tunicates can be found along the West Coast of North America from British Columbia to Baja California. They prefer rocky shores or substrate where there are powerful currents or wave action.