A chordate is a deuterostomic bilaterial animal belonging to the phylum Chordata. All chordates possess, at some point during their larval or adult stages, five distinctive physical characteristics (synapomorphies) that distinguish them from other taxa. These five synapomorphies are a notochord, a hollow dorsal nerve cord, an endostyle or thyroid, pharyngeal slits, and a post-anal tail.
Marine biology is the scientific study of the biology of marine life, organisms that inhabit the sea. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather than on taxonomy.
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.
Thaliacea is a class of marine chordates within the subphylum Tunicata, comprising the salps, pyrosomes and doliolids. Unlike their benthic relatives the ascidians, from which they are believed to have emerged, thaliaceans are free-floating (pelagic) for their entire lifespan. The group includes species with complex life cycles, with both solitary and colonial forms.
Larvaceans or appendicularians, class Appendicularia, are solitary, free-swimming tunicates found throughout the world's oceans. While larvaceans are filter feeders like most other tunicates, they keep their tadpole-like shape as adults, with the notochord running through the tail. They can be found in the pelagic zone, specifically in the photic zone, or sometimes deeper. They are transparent planktonic animals, usually ranging from 2 mm (0.079 in) to 8 mm (0.31 in) in body length including the tail, although giant larvaceans can reach up to 10 cm (3.9 in) in length.
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.
Zoogeography is the branch of the science of biogeography that is concerned with geographic distribution of animal species.
Pyrosomes are free-floating colonial tunicates in family Pyrosomatidae. There are three genera, Pyrosoma, Pyrosomella and Pyrostremma, and eight species. They usually live in the upper layers of the open ocean in warm seas, although some may be found at greater depths.
Pelagic fish live in the pelagic zone of ocean or lake waters—being neither close to the bottom nor near the shore—in contrast with demersal fish that live on or near the bottom, and reef fish that are associated with coral reefs.
The grey-headed albatross also known as the gray-headed mollymawk, is a large seabird from the albatross family. It has a circumpolar distribution, nesting on isolated islands in the Southern Ocean and feeding at high latitudes, further south than any of the other mollymawks. Its name derives from its ashy-gray head, throat and upper neck.
Thorson's rule is an ecogeographical rule which states that benthic marine invertebrates at low latitudes tend to produce large numbers of eggs developing to pelagic and widely dispersing larvae, whereas at high latitudes such organisms tend to produce fewer and larger lecithotrophic (yolk-feeding) eggs and larger offspring, often by viviparity or ovoviviparity, which are often brooded.
Oikopleura is a genus of tunicates in the class Appendicularia (larvaceans). It forms a mucus house every four hours at 20 degrees Celsius. This house has a coarse mesh to keep out big particles, and a fine mesh that collects the small particles, down to the nanoplankton that includes (pelagic) bacteria.
Styela clava is a solitary, subtidal ascidian tunicate. It has a variety of common names such as the stalked sea squirt, clubbed tunicate, Asian tunicate, leathery sea squirt, or rough sea squirt. As its common names suggest, S. clava is club-shaped with an elongated oval body and a long peduncle for attaching to a substrate. Although native to the northwestern waters of the Pacific Ocean, since the 1900s, S. clava has become an increasingly successful invasive species outside of its native range. It is edible.
CalCOFI is a multi-agency partnership formed in 1949 to investigate the collapse of the sardine population off California. The organization's members are from NOAA Fisheries Service, Scripps Institution of Oceanography, and California Department of Fish and Wildlife. The scope of this research has evolved into the study of marine ecosystems off California and the management of its fisheries resources. In 2004, the CalCOFI survey area became one of 26 Long Term Ecological Research Network (LTER) research sites. This time-series of oceanographic and fisheries data allows scientists to assess the human impact and effects of climate change on the coastal ocean ecosystem. CalCOFI hydrographic and biological data, publications, and web information are distributed for use without restriction under the terms of the GNU Free Documentation License.
Quentin Bone FRS was a British marine biologist. In 1971, he pioneered the application of electron microscopy to marine life.
Martin David Burkenroad was an American marine biologist. He specialized in decapod crustaceans and fisheries science.
Oikopleura cophocerca is a species of small pelagic tunicate found in the surface waters of most of the world's oceans. It superficially resembles a tadpole and is surrounded by a transparent mucus net known as a "house".
Polyandrocarpa is a genus of ascidian tunicates within the family Styelidae.
Bathochordaeus, the giant larvaceans, is a genus of larvacean tunicates in the family Oikopleuridae. They are free-swimming filter-feeding marine animals that build mucus bubbles. They eat tiny particles of dead or drifting organic material that float through the water column, which contribute to the oceanic carbon cycle and the accelerated transfer of carbon to the deep sea.
Kowalevskia is a genus of larvacean tunicates, the only one in the family Kowalevskiidae.
