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Polycarpa Pomaria
''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 . Description ''Polycarpa pomaria'' is a solitary tunicate with a conical, ovoid or globular form, growing to a length of about . The buccal siphon at the apex has four lobes and is surrounded by about 56 tentacles of various sizes. The atrial siphon is on the side and also has four lobes. The test or tunic is brown, wrinkled and leathery, with many fleshy papillae. Internally the body wall has numerous drop-shaped gonads (called polycarps) and the pharynx wall is perforated with many bands of stigmata (slits). Distribution and habitat ''Polycarpa pomaria'' is found in the northeastern Atlantic Ocean and the North Sea. Its range extends from Norway and Spitsbergen southwards to the Mediterranean Sea. It occurs on rocks and other hard surfaces and its depth range is from the subtidal zone down to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can reproduction, produce Fertility, fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a binomial nomenclature, two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunicate
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 (including vertebrates). 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'. Some tunicates live as solitary individuals, but others replicate by budding and become colonies, each unit being known as a zooid. They are marine filter feeders with a water-filled, sac-like body structure and two tubular openings, known as siphons, through which they draw in and expel water. During their respiration and feeding, they take in water through the incurrent (or inhalant) siphon and expel the filtered water through the excurrent (or exhalant) siphon. Most adult tunicates are sessile, immobile an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Styelidae
Styelidae is a family of ascidian tunicates.Lambert, G.; Gittenberger, A.; Sanamyan, K. (2015)Styelidae Sluiter, 1895.In: Shenkar, N.; Gittenberger, A.; Lambert, G.; Rius, M.; Moreira Da Rocha, R.; Swalla, B.J.; Turon, X. (2015) Ascidiacea World Database. Accessed through: World Register of Marine Species on 2015-12-23 Genera *''Alloeocarpa'' Michaelsen, 1900 *''Arnbackia'' Brewin, 1950 *''Asterocarpa'' Brewin, 1946 *''Bathyoncus'' Herdman, 1882 *''Bathystyeloides'' Seeliger, 1907 *''Berillia'' Brewin, 1952 *''Botryllocarpa'' Hartmeyer, 1909 *''Botrylloides'' Milne-Edwards, 1841 *''Botryllus'' Gaertner, 1774 *'' Chorizocarpa'' Michaelsen, 1904 * ''Chorizocormus'' Herdman, 1886 *'' Cnemidocarpa'' Huntsman, 1913 *'' Dendrodoa'' MacLeay, 1824 *'' Dextrocarpa'' Millar, 1955 *'' Diandrocarpa'' Van Name, 1902 *'' Dicarpa'' Millar, 1955 *''Distomus'' Gaertner, 1774 *''Eusynstyela'' Michaelsen, 1904 *'' Gynandrocarpa'' Michaelsen, 1900 *'' Kukenthalia'' Hartmeyer, 1903 *''Metandrocarpa'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Test (biology)
In biology, a test is the hard shell of some spherical marine animals and protists, notably sea urchins and microorganisms such as testate foraminiferans, radiolarians, and testate amoebae. The term is also applied to the covering of scale insects. The related Latin term testa is used for the hard seed coat of plant seeds. Etymology The anatomical term "test" derives from the Latin ''testa'' (which means a rounded bowl, amphora or bottle). Structure The test is a skeletal structure, made of hard material such as calcium carbonate, silica, chitin or composite materials. As such, it allows the protection of the internal organs and the attachment of soft flesh. In sea urchins The test of sea urchins is made of calcium carbonate, strengthened by a framework of calcite monocrystals, in a characteristic "stereomic" structure. These two ingredients provide sea urchins with a great solidity and a moderate weight, as well as the capacity to regenerate the mesh from the cuti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Sea
The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Sea in the north. It is more than long and wide, covering . It hosts key north European shipping lanes and is a major fishery. The coast is a popular destination for recreation and tourism in bordering countries, and a rich source of energy resources, including wind and wave power. The North Sea has featured prominently in geopolitical and military affairs, particularly in Northern Europe, from the Middle Ages to the modern era. It was also important globally through the power northern Europeans projected worldwide during much of the Middle Ages and into the modern era. The North Sea was the centre of the Vikings' rise. The Hanseatic League, the Dutch Republic, and the British each sought to gain command of the North Sea and access ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spitsbergen
Spitsbergen (; formerly known as West Spitsbergen; Norwegian: ''Vest Spitsbergen'' or ''Vestspitsbergen'' , also sometimes spelled Spitzbergen) is the largest and the only permanently populated island of the Svalbard archipelago in northern Norway. Constituting the westernmost bulk of the archipelago, it borders the Arctic Ocean, the Norwegian Sea, and the Greenland Sea. Spitsbergen covers an area of , making it the largest island in Norway and the 36th-largest in the world. The administrative centre is Longyearbyen. Other settlements, in addition to research outposts, are the Russian mining community of Barentsburg, the research community of Ny-Ålesund, and the mining outpost of Sveagruva. Spitsbergen was covered in of ice in 1999, which was approximately 58.5% of the island's total area. The island was first used as a whaling base in the 17th and 18th centuries, after which it was abandoned. Coal mining started at the end of the 19th century, and several permanent com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the east by the Levant. The Sea has played a central role in the history of Western civilization. Geological evidence indicates that around 5.9 million years ago, the Mediterranean was cut off from the Atlantic and was partly or completely desiccated over a period of some 600,000 years during the Messinian salinity crisis before being refilled by the Zanclean flood about 5.3 million years ago. The Mediterranean Sea covers an area of about , representing 0.7% of the global ocean surface, but its connection to the Atlantic via the Strait of Gibraltar—the narrow strait that connects the Atlantic Ocean to the Mediterranean Sea and separates the Iberian Peninsula in Europe from Morocco in Africa—is only wide. The Mediterranean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neritic Zone
The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth. From the point of view of marine biology it forms a relatively stable and well-illuminated environment for marine life, from plankton up to large fish and corals, while physical oceanography sees it as where the oceanic system interacts with the coast. Definition (marine biology), context, extra terminology In marine biology, the neritic zone, also called coastal waters, the coastal ocean or the sublittoral zone, refers to that zone of the ocean where sunlight reaches the ocean floor, that is, where the water is never so deep as to take it out of the photic zone. It extends from the low tide mark to the edge of the continental shelf, with a relatively shallow depth extending to about 200 meters (660 feet). Above the neritic zone lie the intertidal (or eulittoral) and supralittoral zones; below it the continental slope be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plankton
Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish and whales. Marine plankton include bacteria, archaea, algae, protozoa and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in the freshwaters of lakes and rivers. Plankton are usually thought of as inhabiting water, but there are also airborne versions, the aeroplankton, that live part of their lives drifting in the atmosphere. These include plant spores, pollen and wind-scattered seeds, as well as microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air by sea spray. Though m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viviparous
Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the mother. The term 'viviparity' and its adjective form 'viviparous' derive from the Latin ''vivus'' meaning "living" and ''pario'' meaning "give birth to". Reproductive mode Five modes of reproduction have been differentiated in animals based on relations between zygote and parents. The five include two nonviviparous modes: ovuliparity, with external fertilisation, and oviparity, with internal fertilisation. In the latter, the female lays zygotes as eggs with a large yolk; this occurs in all birds, most reptiles, and some fishes. These modes are distinguished from viviparity, which covers all the modes that result in live birth: *Histotrophic viviparity: the zygotes develop in the female's oviducts, but find their nutrients by oopha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insects, fish, amphibians, mollusks, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis, which is often accompanied by a change of nutrition source or behavior. Animals can be divided into species that undergo complete metamorphosis (" holometaboly"), incomplete metamorphosis (" hemimetaboly"), or no metamorphosis (" ametaboly"). Scientific usage of the term is technically precise, and it is not applied to general aspects of cell growth, including rapid growth spurts. Generally organisms with a larva stage undergo metamorphosis, and during metamorphosis the organism loses larval characteristics. References to "metamorphosis" in mammals are imprecise and only colloquial, but historically idealist ideas of transf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
