Sea squirt , also called ascidian , any member of the invertebrate class Ascidiacea subphylum Urochordata , also called Tunicata , marine animals with some primitive vertebrate features. Sea squirts are primarily sessile permanently fixed to a surface , potato-shaped organisms found in all seas, from the intertidal zone to the greatest depths. Some species live individually; others live in groups or colonies. The body has an outer protective covering, the tunic, which contains a cellulose -like substance. Sea squirts have two large pores, one to guide water into the body cavity the oral, or branchial, aperture , the other serving as an exit the atrial, or cloacal, aperture. Water is propelled through the animal by pharyngeal cilia.
Born looking similar to tadpoles with a backbone and muscular tail, the sea squirt is free to explore the ocean. The young sea squirt is tasked with finding a suitable place to live the rest of its life. It does this using its sucker located on its head. Once attached to the surface, whether that is the sea bed, bottom of a ship or back of a crab, the sea squirt no longer needs its brain. In fact, shortly after finding the surface to spend the rest of its life on, the sea squirt eats its own brain and its tail disappears.
The siphons are used primarily for feeding and reproduction. The test is a protective mechanism. However, they do tend to live in clusters composed of more Styela plicata, as well as countless other organisms. They are found throughout the warmer areas of the Atlantic, Pacific, and Indian oceans, as well as the Gulf of Mexico and the Caribbean.
Toggle navigation. Sea squirt Facts Sea squirts are immobile sessile marine creatures that belong to the group of tunicates. There are more than 3.