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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] |
Antarctic Krill
Antarctic krill (''Euphausia superba'') is a species of krill found in the Antarctic waters of the Southern Ocean. It is a small, swimming crustacean that lives in large schools, called swarms, sometimes reaching densities of 10,000–30,000 individual animals per cubic metre. It feeds directly on minute phytoplankton, thereby using the primary production energy that the phytoplankton originally derived from the sun in order to sustain their pelagic (open ocean) life cycle. It grows to a length of , weighs up to , and can live for up to six years. It is a key species in the Antarctic ecosystem and in terms of biomass, is one of the most abundant animal species on the planet (approximately 500 million tons, corresponding to 300 to 400 trillion individuals). Life cycle The main spawning season of Antarctic krill is from January to March, both above the continental shelf and also in the upper region of deep sea oceanic areas. In the typical way of all krill, the male attaches a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustacean
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea. Some crustaceans (Remipedia, Cephalocarida, Branchiopoda) are more closely related to insects and the other hexapods than they are to certain other crustaceans. The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese spider crab with a leg span of up to and a mass of . Like other arthropods, crustaceans have an exoskeleton, which they moult to grow. They are distinguished from other groups of arthropods, such as insects, myriapods and chelicerates, by the possession of biramous (two-parted) limbs, and by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biomass (ecology)
The biomass is the mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to ''species biomass'', which is the mass of one or more species, or to ''community biomass'', which is the mass of all species in the community. It can include microorganisms, plants or animals. The mass can be expressed as the average mass per unit area, or as the total mass in the community. How biomass is measured depends on why it is being measured. Sometimes, the biomass is regarded as the natural mass of organisms ''in situ'', just as they are. For example, in a salmon fishery, the salmon biomass might be regarded as the total wet weight the salmon would have if they were taken out of the water. In other contexts, biomass can be measured in terms of the dried organic mass, so perhaps only 30% of the actual weight might count, the rest being water. For other purposes, only biological tissues count, and teeth, bones and shells are excluded. In some appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thysanoessa
Thysanoessa Abstract ''Thysanoessa'' is a genus of the krill that play critical roles in the marine food web. They're abundant in Arctic and Antarctic areas, feeding on zooplankton and detritus to obtain energy. Thysanoessa are responsible for the transportation of carbon and nutrients from surface waters to deeper trophic levels. This genus serves as prey for various fish and provide energy to marine ecosystems as they are at a low trophic level. Most travel through vertical migration, meaning they travel up and down in the water column, providing food for predators at the surface during the night, and at deeper levels during the day. Growth & Development Longevity in this genus varies depending on the specie. The average lifespan for the Thysanoessa is between three and four years. The development and growth of this organism takes place during winter to autumn. Thysanoessa are Spawn (biology), broadcast spawners, meaning that the males will physically put their sperm onto t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Ocean
The Southern Ocean, also known as the Antarctic Ocean, comprises the southernmost waters of the World Ocean, generally taken to be south of 60° S latitude and encircling Antarctica. With a size of , it is regarded as the second-smallest of the five principal oceanic divisions: smaller than the Pacific, Atlantic, and Indian oceans but larger than the Arctic Ocean. Over the past 30 years, the Southern Ocean has been subject to rapid climate change, which has led to changes in the marine ecosystem. By way of his voyages in the 1770s, James Cook proved that waters encompassed the southern latitudes of the globe. Since then, geographers have disagreed on the Southern Ocean's northern boundary or even existence, considering the waters as various parts of the Pacific, Atlantic, and Indian oceans, instead. However, according to Commodore John Leech of the International Hydrographic Organization (IHO), recent oceanographic research has discovered the importance of Southern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zooplankton
Zooplankton are the animal component of the planktonic community ("zoo" comes from the Greek word for ''animal''). Plankton are aquatic organisms that are unable to swim effectively against currents, and consequently drift or are carried along by currents in the ocean, or by currents in seas, lakes or rivers. Zooplankton can be contrasted with phytoplankton, which are the plant component of the plankton community ("phyto" comes from the Greek word for ''plant''). Zooplankton are heterotrophic (other-feeding), whereas phytoplankton are autotrophic (self-feeding). This means zooplankton cannot manufacture their own food but must eat other plants or animals instead — in particular they eat phytoplankton. Zooplankton are generally larger than phytoplankton, most are microscopic, but some (such as jellyfish) are macroscopic and can be seen with the naked eye. Many protozoans (single-celled protists that prey on other microscopic life) are zooplankton, including zooflagellates, fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Krill
Northern krill (''Meganyctiphanes norvegica'') is a species of krill that lives in the North Atlantic Ocean. It is an important component of the zooplankton, providing food for whales, Pinniped, seals, fish and birds. (In the Southern Ocean, Antarctic krill ''Euphausia superba'' fills a similar role.) ''M. norvegica'' is the only species recognised in the genus ''Meganyctiphanes'', although it has been known by several synonym (taxonomy), synonyms: *''Euphausia intermedia'' *''Euphausia lanei'' Holt & Tattersall, 1905 *''Meganyctiphanes calmani'' *''Nyctiphanes norvegicus'' G. O. Sars, 1883 *''Thysanopoda norvegica'' References External links * * * * Krill Crustaceans of the Atlantic Ocean Crustaceans described in 1856 {{Malacostraca-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meganyctiphanes
Northern krill (''Meganyctiphanes norvegica'') is a species of krill that lives in the North Atlantic Ocean. It is an important component of the zooplankton, providing food for whales, seals, fish and birds. (In the Southern Ocean, Antarctic krill ''Euphausia superba'' fills a similar role.) ''M. norvegica'' is the only species recognised in the genus ''Meganyctiphanes'', although it has been known by several synonyms A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...: *''Euphausia intermedia'' *''Euphausia lanei'' Holt & Tattersall, 1905 *''Meganyctiphanes calmani'' *''Nyctiphanes norvegicus'' G. O. Sars, 1883 *''Thysanopoda norvegica'' References External links * * * * Krill Crustaceans of the Atlantic Ocean Crustaceans described in 1856 {{Malacostraca-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bentheuphausia
''Bentheuphausia amblyops'', the deep sea krill is a species of krill. ''B. amblyops'' is the only species within its genus, which in turn is the only genus within the family Bentheuphausiidae. All the 85 other species of krill known are classified in the family Euphausiidae. Distribution ''B. amblyops'' occurs in the northern Atlantic Ocean in latitudes south of 40° N, and also in the southern seas of the Atlantic, in the Indian Ocean and in the Pacific. It is a bathypelagic krill that lives in deep waters below . Description It is distinguished from the Euphausiidae by several morphological features, the most apparent being that they are not bioluminescent and that their first pair of pleopod The decapod ( crustaceans such as a crab, lobster, shrimp or prawn) is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various ...s is not modified as copulator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euphausia
''Euphausia'' is the largest genus of krill, and is placed in the family Euphausiidae. There are 31 species known in this genus, including Antarctic krill (''Euphausia superba'') and ice krill ('' Euphausia crystallorophias'') from the Southern Ocean, and North Pacific krill (''Euphausia pacifica'') in the Pacific Ocean. *''Euphausia americana'' Hansen, 1911 *'' Euphausia brevis'' Hansen, 1905 *'' Euphausia crystallorophias'' Holt & Tattersall, 1906 *''Euphausia diomedeae'' Ortmann, 1894 *'' Euphausia distinguenda'' Hansen, 1908 *''Euphausia eximia'' Hansen, 1911 *'' Euphausia fallax'' Hansen, 1916 *'' Euphausia frigida'' Hansen, 1911 *''Euphausia gibba'' G. O. Sars, 1883 *''Euphausia gibboides'' Ortmann, 1893 *'' Euphausia hanseni'' Zimmer, 1915 *'' Euphausia hemigibba'' Hansen, 1910 *''Euphausia krohnii'' (Brandt, 1851) *''Euphausia lamelligera'' Hansen, 1911 *''Euphausia longirostris'' Hansen, 1908 *''Euphausia lucens'' Hansen, 1905 *''Euphausia mucronata'' G. O. Sars, 1883 *'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nyctiphanes
''Nyctiphanes'' is a genus of krill, comprising four species with an anti-tropical distribution. Based on molecular phylogenetic analyses of the cytochrome oxidase gene and 16S ribosomal DNA, ''Nyctiphanes'' is believed to have evolved during the Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen .... References Krill Crustacean genera Taxa named by Georg Ossian Sars {{Malacostraca-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudeuphausia
''Pseudeuphausia'' is a genus of krill (small marine crustaceans) comprising two species: *'' Pseudeuphausia latifrons'' (G. O. Sars Prof Georg Ossian Sars H FRSE (20 April 1837 – 9 April 1927) was a Norwegian marine and freshwater biologist. Life Georg Ossian Sars was born on 20 April 1837 in Kinn, Norway (now part of Flora), the son of Pastor Michael Sars and Maren S ..., 1883) *'' Pseudeuphausia sinica'' Wang & Chen, 1963 References Krill Crustacean genera Taxa named by Hans Jacob Hansen {{Malacostraca-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
