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Helicolenus Hilgendorfii
''Helicolenus hilgendorfii'', Hilgendorf's saucord, is a species of marine ray-finned fish belonging to the subfamily Sebastinae, part of the family Scorpaenidae. It is found in the northwestern Pacific Ocean. Taxonomy ''Helicolenus hilgendorfii'' was first formally described in 1884 as ''Sebastes hilgendorfii'' by the German zoologist Ludwig Heinrich Philipp Döderlein with the type locality given as Tokyo, although no types are known. Döderlein did not state who was honoured in the specific name but it is certainly the German zoologist and palaeontologist Franz Martin Hilgendorf whose work on Japanese fishes was often referred to by Döderlein. Description ''Helicolenus hilgendorfii'' attains a maximum standard length of . It has an elongated, compressed body with a large head which has weak spines. The orbit protrudes a little over the dorsal profile of the head. They do not have a swim bladder. There are no teeth in the front of the jaws. The preoperculum has 5 spines an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludwig Heinrich Philipp Döderlein
Ludwig Heinrich Philipp Döderlein (3 March 1855, Bad Bergzabern – 23 April 1936, Munich) was a German zoologist. He specialized in echinoderms, particularly sea stars, sea urchins, and crinoids. He was one of the first European zoologists to have the opportunity to do research work in Japan from 1879 to 1881. Today, he is considered one of the most important pioneers of marine biological research in Japan. He was the director and curator of the Musée zoologique de la ville de Strasbourg from 1882 to 1919. He headed the Zoologische Staatssammlung München from 1923 to 1927 and was Professor of Zoology in the Ludwig Maximilian University of Munich. Biography Ludwig Döderlein was born in Bad Bergzabern, then Kingdom of Bavaria, on March 3, 1855. He went to school in Bayreuth from 1864 to 1873. From 1873 to 1875 he studied natural sciences in the University of Erlangen, where he also worked as an assistant to the Zoologist Emil Selenka in the summer of 1875. From 1875 to 1876 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lateral Line
The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial cells, known as hair cells, which respond to displacement caused by motion and transduce these signals into electrical impulses via excitatory synapses. Lateral lines serve an important role in schooling behavior, predation, and orientation. Fish can use their lateral line system to follow the vortices produced by fleeing prey. Lateral lines are usually visible as faint lines of pores running lengthwise down each side, from the vicinity of the gill covers to the base of the tail. In some species, the receptive organs of the lateral line have been modified to function as electroreceptors, which are organs used to detect electrical impulses, and as such, these systems remain closely linked. Most amphibian larvae and some fully aquatic adult ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicolenus
''Helicolenus'' is a genus of marine ray-finned fishes belonging to the family Scorpaenidae where they are classified within the subfamily Sebastinae, the rockfishes. The species in this genus are found in the Indian, Atlantic and Pacific oceans. Taxonomy ''Helicolenus'' was described by a genus in 1896 by the American ichthyologists George Brown Goode & Tarleton Hoffman Bean using ''Scorpaena dactyloptera'' as its type species which had originally been described by the Genevan physician, naturalist, chemist, botanist and ichthyologist François Étienne Delaroche in 1809. The genus name is a compound of ''helikos'' which means "twisted" or "curved" but meaning "strong" according to Goode and Bean, possibly in error for ''hadros''; and ''oleni'' meaning "elbow" or "arm", an allusion to the “strong pectoral fins” of ''H. dactylopterus''. Species There are 9 recognised species: * '' Helicolenus avius'' T. Abe & Eschmeyer, 1972 * '' Helicolenus barathri'' (Hector, 1875) (big ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euphausia Pacifica
''Euphausia pacifica'', the North Pacific krill, is a euphausid that lives in the northern Pacific Ocean. In Japan, ''E. pacifica'' is called ''isada krill'' or ' (ツノナシオキアミ). It is found from Suruga Bay northwards, including all of the Sea of Japan and the south-western part of the Sea of Okhotsk. ''E. pacifica'' is fished from Cape Inubō north. The annual catch of krill in Japanese seas is limited to 70,000 metric tonnes by government regulations. ''E. pacifica'' is also fished, albeit on a smaller scale, in the waters of British Columbia, Canada. ''E. pacifica'' is a major food item for various fish, including Pacific cod, Alaska pollock, chub mackerel, sand lance, North Pacific hake, Pacific herring, dogfish, sablefish, Pacific halibut, chinook salmon and coho salmon The coho salmon (''Oncorhynchus kisutch;'' Karuk: achvuun) is a species of anadromous fish in the salmon family and one of the five Pacific salmon species. Coho salmon are also known as s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Krill
Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name "krill" comes from the Norwegian Norwegian, Norwayan, or Norsk may refer to: *Something of, from, or related to Norway, a country in northwestern Europe * Norwegians, both a nation and an ethnic group native to Norway * Demographics of Norway *The Norwegian language, including ... word ', meaning "small fry of fish", which is also often attributed to species of fish. Krill are considered an important trophic level connection – near the bottom of the food chain. They feed on phytoplankton and (to a lesser extent) zooplankton, yet also are the main source of food for many larger animals. In the Southern Ocean, one species, the Antarctic krill, ''Euphausia superba'', makes up an estimated biomass (ecology), biomass of around 379,000,000 tonnes, making it among the species with the largest total biomass. Over half of this biomass is eaten by whales, Pinniped, seals, pen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crangon Hakodatei
''Crangon'' is a genus of shrimp. Distribution ''Crangon'' species are found exclusively in the Northern Hemisphere, with most of the species occurring in the northern Pacific Ocean. '' C. septemspinosa'' is the only species in the genus to occur in the north-western Atlantic Ocean, while in the north-eastern Atlantic, '' C. crangon'' and '' C. allmani'' occur. With the exception of the important commercial species ''C. crangon'', however, the distributions of ''Crangon'' species are poorly characterised. The greater number of species in the Pacific Ocean is thought to indicate that the genus originated in the Pacific. Species ''Crangon'' contains the following extant species: *'' Crangon affinis'' De Haan, 1849 *'' Crangon alaskensis'' Lockington, 1877 *'' Crangon alba'' Holmes, 1900 *'' Crangon allmani'' Kinahan, 1860 *'' Crangon amurensis'' Bražnikov, 1907 *'' Crangon capensis'' Stimpson, 1860 *'' Crangon cassiope'' De Man, 1906 *''Crangon crangon'' (Lin ... [...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 oophagy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demersal Fish
Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They occupy the sea floors and lake beds, which usually consist of mud, sand, gravel or rocks. In coastal waters they are found on or near the continental shelf, and in deep waters they are found on or near the continental slope or along the continental rise. They are not generally found in the deepest waters, such as abyssal depths or on the abyssal plain, but they can be found around seamounts and islands. The word ''demersal'' comes from the Latin ''demergere'', which means ''to sink''. Demersal fish are bottom feeders. They can be contrasted with pelagic fish which live and feed away from the bottom in the open water column. Demersal fish fillets contain little fish oil (one to four percent), whereas pelagic fish can contain up to 30 percent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East China Sea
The East China Sea is an arm of the Western Pacific Ocean, located directly offshore from East China. It covers an area of roughly . The sea’s northern extension between mainland China and the Korean Peninsula is the Yellow Sea, separated by an imaginary line between the eastern tip of Qidong at the Yangtze River estuary and the southwestern tip of South Korea's Jeju Island. The East China Sea is bounded in the east and southeast by the middle portion of the first island chain off the eastern Eurasian continental mainland, including the Japanese island of Kyushu and the Ryukyu Islands, and in the south by the island of Taiwan. It connects with the Sea of Japan in the northeast through the Korea Strait, the South China Sea in the southwest via the Taiwan Strait, and the Philippine Sea in the southeast via gaps between the various Ryukyu Islands (e.g. Tokara Strait and Miyako Strait). Most of the East China Sea is shallow, with almost three-fourths of it being less than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Truncate
In mathematics and computer science, truncation is limiting the number of digits right of the decimal point. Truncation and floor function Truncation of positive real numbers can be done using the floor function. Given a number x \in \mathbb_+ to be truncated and n \in \mathbb_0, the number of elements to be kept behind the decimal point, the truncated value of x is :\operatorname(x,n) = \frac. However, for negative numbers truncation does not round in the same direction as the floor function: truncation always rounds toward zero, the floor function rounds towards negative infinity. For a given number x \in \mathbb_-, the function ceil is used instead. :\operatorname(x,n) = \frac In some cases is written as . See Notation of floor and ceiling functions. Causes of truncation With computers, truncation can occur when a decimal number is typecast as an integer; it is truncated to zero decimal digits because integers cannot store non-integer real numbers. In algebra An ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to lu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelvic Fin
Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two endochondrally-derived bony girdles attached to bony radials. Dermal fin rays (lepidotrichia) are positioned distally from the radials. There are three pairs of muscles each on the dorsal and ventral side of the pelvic fin girdle that abduct and adduct the fin from the body. Pelvic fin structures can be extremely specialized in actinopterygians. Gobiids and lumpsuckers modify their pelvic fins into a sucker disk that allow them to adhere to the substrate or climb structures, such as waterfalls. In priapiumfish, males have modified their pelvic structures into a spiny copulatory device that grasps the female during mating. File:Pelvic fin skeleton.png, Pelvic fin skeleton for ''Danio rerio'', zebrafish. File:Zuignap waarmee de zwartbekgrond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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