A tunicate is an exclusively marine invertebrate animal, a member of the subphylum Tunicata. This grouping is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords. The subphylum was at one time called Urochordata, and the term urochordates is still sometimes used for these animals. They are the only chordates that have lost their myomeric segmentation, with the possible exception of the seriation of the gill slits. However, doliolids still display segmentation of the muscle bands.
Membranipora membranacea is a very widely distributed species of marine bryozoan known from the Atlantic and Pacific Oceans, usually in temperate zone environments. This bryozoan is a colonial organism characterized by a thin, mat-like encrustation, white to gray in color. It may be known colloquially as the coffin box, sea-mat or lacy crust bryozoan and is often abundantly found encrusting seaweeds, particularly kelps.
Ascidiacea, commonly known as the ascidians or sea squirts, is a paraphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer "tunic" made of a polysaccharide.
Botrylloides leachii is a colonial tunicate of the family Styelidae. Its unique methods of propagation and regeneration make it an ideal model organism for use in biological study of development, immunology, stem cells, and regeneration.
Ecteinascidia turbinata, commonly known as the mangrove tunicate, is a species of tunicate in the family Perophoridae. It was described to science in 1880 by William Abbott Herdman. The cancer drug trabectedin can be isolated from this species.
Didemnum molle is a species of colonial tunicate in the family Didemnidae. It is commonly known as the tall urn ascidian, the green barrel sea squirt or the green reef sea-squirt. It is native to the Red Sea and the tropical waters of the Indo-Pacific region.
Didemnum vexillum is a species of colonial tunicate in the family Didemnidae. It is commonly called sea vomit, marine vomit, pancake batter tunicate, or carpet sea squirt. It is thought to be native to Japan, but it has been reported as an invasive species in a number of places in Europe, North America and New Zealand. It is sometimes given the nickname "D. vex" because of the vexing way in which it dominates marine ecosystems when introduced into new locations; however, the species epithet vexillum actually derives from the Latin word for flag, and the species was so named because of the way colonies' long tendrils appear to wave in the water like a flag.
Perophora viridis, the honeysuckle tunicate, is a species of colonial sea squirt in the genus Perophora found in the tropical western Atlantic Ocean.
Perophora multiclathrata is a species of colonial sea squirt in the genus Perophora. It is native to the tropical Indo-Pacific and the western Atlantic Ocean.
Diazona violacea is a species of tunicate, an ascidian in the family Diazonidae. It is the type species of the genus Diazona.
Morchellium argus, the red-flake ascidian, is a species of colonial sea squirt, a tunicate in the family Polyclinidae. It is native to shallow water in the northeastern Atlantic Ocean, especially round the coasts of Britain.
Polyclinum aurantium is a species of colonial sea squirt, a tunicate in the family Polyclinidae. It is native to shallow water in the northeastern Atlantic Ocean and Mediterranean Sea.
Polycarpa pomaria is a species of tunicate or sea squirt in the family Styelidae. It is native to the northeastern Atlantic Ocean where it lives on the seabed at depths down to about 450 metres (1,500 ft).
Synoicum pulmonaria, the tennis ball ascidian or sea-fig, is a species of colonial sea squirt, a tunicate in the family Polyclinidae. It occurs in shallow water in the northeastern Atlantic Ocean, the North Sea and the English Channel, and also, to a lesser extent, in the northwestern Atlantic Ocean.
Distomus is a genus of ascidian tunicates in the family Styelidae.
Stolonica is a genus of ascidian tunicates in the family Styelidae.
Dendrodoa grossularia is a species of tunicate or sea squirt in the family Styelidae, commonly known as the baked bean ascidian. It is native to the northeastern Atlantic Ocean where it is common in shallow water and on the lower shore in exposed rocky sites.
Stolonica socialis is a species of tunicate or sea squirt in the family Styelidae, commonly known as orange sea grapes. It is native to the northeastern Atlantic Ocean, where it lives on the rocky seabed in shallow water.
Pyura haustor is a species of sessile ascidian, or sea squirt, that lives in coastal waters in the north-eastern Pacific Ocean, attached to rocks or artificial structures. Common names for this species include the wrinkled seapump, the wrinkled sea squirt and the warty tunicate.
Halocynthia igaboja, commonly known as sea hedgehog, bristly tunicate or spiny sea squirt, is a species of tunicate in the family Pyuridae. It is native to the northeastern Pacific Ocean. This species was first described in 1906 by the Japanese marine biologist Asajiro Oka, who gave it the name Cynthia ritteri. It was later transferred to the genus Halocynthia.
