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.
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.
Herdmania is a genus of ascidian tunicates in the family Pyuridae.
Ciona intestinalis is an ascidian, a tunicate with very soft tunic. Its Latin name literally means "pillar of intestines", referring to the fact that its body is a soft, translucent column-like structure, resembling a mass of intestines sprouting from a rock. It is a globally distributed cosmopolitan species. Since Linnaeus described the species, Ciona intestinalis has been used as a model invertebrate chordate in developmental biology and genomics. Studies conducted between 2005 and 2010 have shown that there are at least two, possibly four, sister species. More recently it has been shown that one of these species has already been described as Ciona robusta. By anthropogenic means, the species has invaded various parts of the world and is known as an invasive species.
Out-crossing or out-breeding is the technique of crossing between different breeds. This is the practice of introducing distantly related genetic material into a breeding line, thereby increasing genetic diversity.
Botryllus schlosseri is a colonial ascidian tunicate. It is commonly known as the star tunicate, but it also has several other common names, including star ascidian and golden star tunicate. Colonies grow on slow-moving, submerged objects, plants, and animals in nearshore saltwater environments.
The mangrove rivulus or mangrove killifish, Kryptolebias marmoratus, is a species of killifish in the family Rivulidae. It lives in brackish and marine waters along the coasts of Florida, through the Antilles, and along the eastern and northern Atlantic coasts of Mexico, Central America and South America. It has a very wide tolerance of both salinity and temperature, can survive for about two months on land, and mostly breeds by self-fertilization. It is typically found in areas with red mangrove and sometimes lives in burrows of Cardisoma guanhumi crabs.
Corella willmeriana is a solitary tunicate in the family Corellidae. It is native to the eastern Pacific Ocean where it lives on the seabed at depths down to about 75 m (250 ft) between Alaska and California.
Gynodioecy is a rare breeding system that is found in certain flowering plant species in which female and hermaphroditic plants coexist within a population. Gynodioecy is the evolutionary intermediate between hermaphroditism and dioecy.
Sperm chemotaxis is a form of sperm guidance, in which sperm cells (spermatozoa) follow a concentration gradient of a chemoattractant secreted from the oocyte and thereby reach the oocyte.
Clavelina picta, common name the painted tunicate, is a species of tunicate, in the genus Clavelina. These animals, like all ascidians, are sessile filter feeders.
Ascidiella aspersa, the European sea squirt, is a species of solitary sea squirts native to the northeastern Atlantic, from the Mediterranean Sea to Norway. They possess oval bodies up to 50 to 130 mm in length. Their branchial siphons are conical and positioned at the top of the body. They possess six to eight lobes. The atrial siphons are located at the upper third of the side of the body and possess six lobes. The body is covered by a firm transparent test that is greyish to brown in color. The test often snag detritus that remain loosely attached to the animal. When expanded, at most 40 tentacles can be observed on the inside surface of the branchial wall. Both the openings of the branchial and atrial siphons possess lighter colored ridges on their rims. They may also be frilled at times. A. aspersa are attached to the substrates by the left side of their bodies. They can be found in dense groups of unfused individuals on hard surfaces like rocks. at depths of up to 90 m (300 ft).
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.
Ciona savignyi is a marine animal sometimes known as the Pacific transparent sea squirt or solitary sea squirt. It is a species of tunicates in the family Cionidae. It is found in shallow waters around Japan and has spread to the west coast of North America where it is regarded as an invasive species.
Styela angularis is a solitary, hermaphroditic ascidian tunicate that is found along the coast of Southern Africa from Lüderitz Bay in Namibia to the Eastern Cape.
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).
Ciona robusta is a species of marine invertebrate in the genus Ciona of the family Cionidae. The holotype was collected on the northeastern coast of Honshu Island, Japan. Populations of Ciona intestinalis known as Ciona intestinalis type A found in the Mediterranean Sea, the Pacific Ocean, east coast of North America, and the Atlantic coasts of South Africa have been shown to be Ciona robusta.
Cnemidocarpa finmarkiensis is a species of solitary ascidian tunicate in the family Styelidae. Common names include broad base sea squirt, orange sea squirt, red sea squirt, shiny orange sea squirt, shiny red tunicate and Finmark's tunicate. It is native to shallow waters in the northern and northeastern Pacific Ocean.
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.
