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Euphausiid
Krill are small crustaceans of the order Euphausiacea, and are found in all the world's oceans. The name "krill" comes from the Norwegian 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 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, seals, penguins, seabirds, squid, and fish each year. Most krill species display large daily vertical migrations, thus providing food for predators near the surface at night and in deeper waters during the day. Krill are fished commercially in the Southern Ocean and in the waters around Jap ... [...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] |
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] |
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] |
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] |
Walter Medley Tattersall
Walter Medley Tattersall (8 November 1882 – 5 October 1943) was a British zoologist and marine biologist, famous for his study of mysids. He was born in Liverpool, the eldest son of a draper's family. He studied zoology at the University of Liverpool, where he graduated in 1901. Subsequently, he worked as a naturalist for the Irish Fisheries Department under Ernest William Lyons Holt, where he began his studies of crustaceans. In 1909 he became the director of the Manchester Museum and also worked as a tutor in marine biology at the universities of Manchester and Sheffield. During World War I, he served as a private in Flanders and France, where he was wounded and gassed in 1918. In the middle of the war, in 1916, he married Olive Selden Attride (1890–1978). In 1922, he was appointed professor at the University of Cardiff, a post he would hold for the rest of his life. He was highly respected as a teacher in zoology and marine biology and also as a field researcher and taxo ... [...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] |
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] |
Phytoplankton
Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater ecosystems. The name comes from the Greek words (), meaning 'plant', and (), meaning 'wanderer' or 'drifter'. Phytoplankton obtain their energy through photosynthesis, as do trees and other plants on land. This means phytoplankton must have light from the sun, so they live in the well-lit surface layers (euphotic zone) of oceans and lakes. In comparison with terrestrial plants, phytoplankton are distributed over a larger surface area, are exposed to less seasonal variation and have markedly faster turnover rates than trees (days versus decades). As a result, phytoplankton respond rapidly on a global scale to climate variations. Phytoplankton form the base of marine and freshwater food webs and are key players in the global carbon cycle. They account for about half of global photosynthetic activity and at least half of the oxygen production, despite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre André Latreille
Pierre André Latreille (; 29 November 1762 – 6 February 1833) was a French zoologist, specialising in arthropods. Having trained as a Roman Catholic priest before the French Revolution, Latreille was imprisoned, and only regained his freedom after recognising a rare beetle species he found in the prison, ''Necrobia ruficollis''. He published his first important work in 1796 (), and was eventually employed by the . His foresighted work on arthropod systematics and taxonomy gained him respect and accolades, including being asked to write the volume on arthropods for George Cuvier's monumental work, , the only part not by Cuvier himself. Latreille was considered the foremost entomologist of his time, and was described by one of his pupils as "the prince of entomologists". Biography Early life Pierre André Latreille was born on 29 November 1762 in the town of Brive, then in the province of Limousin, as the illegitimate child of Jean Joseph Sahuguet d'Amarzit, général ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trophic Level
The trophic level of an organism is the position it occupies in a food web. A food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it is from the start of the chain. A food web starts at trophic level 1 with primary producers such as plants, can move to herbivores at level 2, carnivores at level 3 or higher, and typically finish with apex predators at level 4 or 5. The path along the chain can form either a one-way flow or a food "web". Ecological communities with higher biodiversity form more complex trophic paths. The word ''trophic'' derives from the Greek τροφή (trophē) referring to food or nourishment. History The concept of trophic level was developed by Raymond Lindeman (1942), based on the terminology of August Thienemann (1926): "producers", "consumers" and "reducers" (modified to "decomposers" by Lindeman). Overview The three basic ways in which org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fry (biology)
Fish go through various life stages between fertilization and adulthood. The life of a fish start as spawned eggs which hatch into immotile larvae. These larval hatchlings are not yet capable of feeding themselves and carry a yolk sac which provides stored nutrition. Before the yolk sac completely disappears, the young fish must mature enough to be able to forage independently. When they have developed to the point where they are capable of feeding by themselves, the fish are called fry. When, in addition, they have developed scales and working fins, the transition to a juvenile fish is complete and it is called a fingerling, so called as they are typically about the size of human fingers. The juvenile stage lasts until the fish is fully grown, sexually mature and interacting with other adult fish. Growth stages Ichthyoplankton ''(planktonic or drifting fish)'' are the eggs and larvae of fish. They are usually found in the sunlit zone of the water column, less than 200 met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
