The Neotropical realm is one of the eight biogeographic realms constituting the Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone.
In geography, the temperate or tepid climates of Earth occur in the middle latitudes, which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout the year and more distinct seasonal changes compared to tropical climates, where such variations are often small. They typically feature four distinct seasons, Summer the warmest, Autumn the transitioning season to Winter, the colder season, and Spring the transitioning season from winter back into summer. On the northern hemisphere the year starts with winter, transitions in the first halfyear through spring into summer which is in mid-year, then at the second halfyear through autumn into winter at year-end. On the southern hemisphere seasons are swapped with summer in between years and winter in mid-year.
The Indomalayan realm is one of the eight biogeographic realms. It extends across most of South and Southeast Asia and into the southern parts of East Asia.
A tunicate is a marine invertebrate animal, a member of the subphylum Tunicata. It 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.
Ciona intestinalis is an ascidian, a tunicate with very soft tunic. Its Latin name means, literally, "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 its 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.
The Aliwal Shoal is a rocky reef which is the remains of an ancient sand dune approximately 5 kilometres (3.1 mi) off the coast of KwaZulu-Natal, South Africa. The reef is inhabited by many kinds of hard and soft corals and a variety of tropical and subtropical fish species. Aliwal Shoal was named after the near-sinking of the 3 Masted vessel "Aliwal", captained by James Anderson, in 1849. There are two wrecks near the reef that are popular recreational dive sites. The Norwegian bulk carrier, the MV Produce which sank in 1974, and the SS Nebo which sank in 1884. Aliwal Shoal has diverse marine life including large predators and is popular as a recreational scuba diving destination. The Shoal is known especially for its abundance of Grey nurse sharks between July and November when the sharks congregate there to mate.
Didemnum is a genus of colonial tunicates in the family Didemnidae. It is the most speciose genus in the didemnid family. Species in this genus often have small calcareous spicules embedded in the tunic and form irregular or lobed colonies. Some Didemnum species, including Didemnum vexillum and Didemnum perlucidem are considered invasive species. In early 2006, Didemnum vexillum was found covering a 230 km2 area of cobble habitat in Georges Bank off the coast of New England, and is classified as an invasive species of greatest concern in coastal areas throughout Europe, New Zealand, and North America. Didemnum sp. invasions have also been recorded in Canada, the Mediterranean, and the Netherlands.
Clavelina robusta is a species of tunicate, in the genus Clavelina. Like all ascidians, these sessile animals are filter feeders.
Pycnoclavella diminuta, known as the white-spotted sea squirt, white-spot ascidian, and white-spotted ascidian, is a species of tunicate, in the genus Pycnoclavella. Like all ascidians, these sessile animals are filter feeders.
Ecteinascidia turbinata, the mangrove tunicate, is a sea squirt species in the genus Ecteinascidia, which was described to science in 1880 by William Abbott Herdman. The cancer drug trabectedin is isolated from E. turbinata.
Polycarpa aurata, also known as the ox heart ascidian, the gold-mouth sea squirt or the ink-spot sea squirt, is a species of tunicate in the family Styelidae.
Didemnum vexillum, the carpet sea squirt, is a species of colonial tunicate in the family Didemnidae. Thought to be native to Japan, 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.
The angular sea squirt, 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.
Pyura haustor is a species of sessile ascidian, or sea squirt, that lives in coastal waters in the northeastern 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.
