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Spotless Smooth-hound
The spotless smooth-hound (''Mustelus griseus'') is a species of houndshark, in the family (biology), family Houndshark, Triakidae, found on the continental shelves of the northwest Pacific, between latitudes 40th parallel north, 40° N and 11th parallel north, 11° N, from the surface to a depth of 300 m. It can grow to a length of up to . Description Male spotless smooth-hounds grow to a length of about with females growing to around . The head is short with a fairly long, bluntly pointed snout and the body is slender. The eyes are small and close together. The mouth is long and the lower lip groove is usually longer than the upper one. The teeth are molar-like with low cusps. Both the dorsal fins have a curved trailing edge and the distance separating them occupies about 20% of the total length of the fish. The dorsal surface and flanks are grey or greyish-brown and the ventral surface is paler. The colour is uniform and there are no spots or bands of darker or lighter colour ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viktor Pietschmann
Viktor Pietschmann (27 October 1881 – 11 November 1956) was an Austrian ichthyologist at the Naturhistorisches Museum, Vienna Museum of Natural History. He was the curator of the fish collection from 1919 to 1946 and made collecting trips to the Barents Sea, Greenland, Mesopotamia, Armenia, Hawaii, Romania, and Poland. Pietschmann described many new fish, including several species of shark, and had more than 50 publications over his career. He served in the Austrian army in World War I, during which he was stationed in the Ottoman Empire. While there, Pietschmann Witnesses and testimonies of the Armenian genocide, witnessed the Armenian genocide and took many photographs of the deportees. He joined the National Socialist German Workers' Party (NSDAP) in 1932 and remained a member until the end of World War II. His zoological author abbreviation is Pietschmann. See also :Taxa named by Viktor Pietschmann, taxa named by Viktor Pietschmann, anthis query Early life Viktor Pietschm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viviparity
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 vitellus, 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 b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Described In 1908
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Fauna Of East Asia
Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (other) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * Marines, a naval-based infantry force ** United States Marine Corps ** Royal Marines of the UK ** Brazilian Marine Corps ** Spanish Marine Infantry ** Fusiliers marins (France) ** Indonesian Marine Corps ** Republic of China Marine Corps ** Republic of Korea Marine Corps ** Royal Thai Marine Corps *"Marine" also means "navy" in several languages: ** Austro-Hungarian Navy () ** Belgian Navy (, , ) ** Royal Canadian Navy () *** Provincial Marine (1796–1910), a predecessor to the Royal Canadian Navy ** Navy of the Democratic Republic of the Congo () ** Royal Danish Navy () ** Finnish Navy (, ) ** French Navy () ** Gabonese Navy () ** German Navy () ** Royal Moroccan Navy () ** Royal Netherlands Navy () ** Swedish Navy () Places * Marin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mustelus
''Mustelus'', also known as the smooth-hounds, is a genus of sharks in the family Triakidae. The name of the genus comes from the Latin word ''mustela'', meaning weasel. It should not be confused with the genus name ''Mustela'', which is used for weasels. A smooth-hound can grow to 159 cm (5 ft. 3 in.) long and weigh more than 13 kg (29 lb). Species Currently, 28 recognized species are placed in this genus: * ''Mustelus albipinnis'' Castro-Aguirre, Antuna-Mendiola, González-Acosta & De La Cruz-Agüero, 2005 (white-margin fin houndshark) * '' Mustelus andamanensis'' White, Arunrugstichai & Naylorn, 2021 (Andaman smooth-hound) * ''Mustelus antarcticus'' Günther, 1870 (gummy shark) * ''Mustelus asterias'' Cloquet, 1821 (starry smooth-hound) * ''Mustelus californicus'' T. N. Gill, 1864 (gray smooth-hound) * ''Mustelus canis'' Mitchill, 1815 ** '' M. c. canis'' Mitchill, 1815 (dusky smooth-hound) ** '' M. c. insularis'' Heemstra, 1997 (Caribbean smoo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partnerships. The organization is best known to the wider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juveniles of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting. Non- marine species (freshwater fish not saltwater fish) that are caught (either intentionally or unintentionally) but regarded as generally "undesirable" are referred to as "rough fish" (mainly US) and " coarse fish" (mainly UK). In 1997, the Organisation for Economic Co-operation and Development (OECD) defined bycatch as "total fishing mortality, excluding that accounted directly by the retained catch of target species". Bycatch contributes to fishery decline and is a mechanism of overfishing for unintentional catch. The average annual bycatch rate of pinnipeds and cetaceans in the US from 199 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longline Fishing
Longline fishing, or longlining, is a commercial fishing angling technique that uses a long ''main line'' with baited hooks attached at intervals via short branch lines called ''snoods'' or ''gangions''.Method and Apparatus for Long Line and Recreational Bait Fishing Patent application 20080202013. 28 August 2008. A snood is attached to the main line using a clip or swivel, with the hook at the other end. Longlines are classified mainly by where they are placed in the . This can be at the surface or at the bottom. Lines can also be set by means of an anchor, or left to drift. Hundreds or even thousands of baited hooks can hang from a single line. This can l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trawling
Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different species of fishes or sometimes targeted species. Trawls are often called towed gear or dragged gear. The boats that are used for trawling are called trawlers or draggers. Trawlers vary in size from small open boats with as little as 30 hp (22 kW) engines to large factory trawlers with over 10,000 hp (7.5 MW). Trawling can be carried out by one trawler or by two trawlers fishing cooperatively (pair trawling). Trawling can be contrasted with trolling. While trawling involves a net and is typically done for commercial usage, trolling instead involves a reed, rod and a bait or a lure and is typically done for recreational purposes. Trawling is also commonly used as a scientific sampling, or survey, method. Bottom vs. midwater trawling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gillnet
Gillnetting is a fishing method that uses gillnets: vertical panels of netting that hang from a line with regularly spaced floaters that hold the line on the surface of the water. The floats are sometimes called "corks" and the line with corks is generally referred to as a "cork line." The line along the bottom of the panels is generally weighted. Traditionally this line has been weighted with lead and may be referred to as "lead line." A gillnet is normally set in a straight line. Gillnets can be characterized by mesh size, as well as colour and type of filament from which they are made. Fish may be caught by gillnets in three ways: # Wedged – held by the mesh around the body. # Gilled – held by mesh slipping behind the opercula. # Tangled – held by teeth, spines, maxillaries, or other protrusions without the body penetrating the mesh. Most often fish are gilled. A fish swims into a net and passes only part way through the mesh. When it struggles to free ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yolk Sac
The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac'' is far more widely used. In humans, the yolk sac is important in early embryonic blood supply, and much of it is incorporated into the primordial gut during the fourth week of embryonic development. In humans The yolk sac is the first element seen within the gestational sac during pregnancy, usually at 3 days gestation. The yolk sac is situated on the front (ventral) part of the embryo; it is lined by extra-embryonic endoderm, outside of which is a layer of extra-embryonic mesenchyme, derived from the epiblast. Blood is conveyed to the wall of the yolk sac by the primitive aorta and after circulating through a wide-meshed capillary plexus, is returned by the vitelline veins to the tubular heart of the embryo. This constitutes the vitell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthos
Benthos (), also known as benthon, is the community of organisms that live on, in, or near the bottom of a sea, river, lake, or stream, also known as the benthic zone.Benthos from the Census of Antarctic Marine Life website This community lives in or near marine or freshwater sedimentary environments, from s along the , out to the , and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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