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Mertensia Ovum
''Mertensia ovum'', also known as the Arctic comb jelly or sea nut, is a cydippid comb jelly or ctenophore first described as ''Beroe ovum'' by Johan Christian Fabricius in 1780. It is the only species in the genus ''Mertensia''. Unusually among ctenophores, which normally prefer warmer waters, it is found in the Arctic and adjacent polar seas, mostly in surface waters down to . In addition to being weakly bioluminescent in blues and greens, comb jellies produce a rainbow effect similar to that seen on an oil slick, and which is caused by interference of incident light on the eight rows of moving cilia or comb rows which propel the organism. The comb rows beat sequentially, rather like the action of a Mexican wave. The comb rows also function as chemical sense organs, serving the same role as insect antennae. ''Mertensia ovum'' is the major source of bioluminescence from Arctic gelatinous zooplankton. This species, like other ctenophores, has a large body cavity and is car ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
René Primevère Lesson
René (''born again'' or ''reborn'' in French) is a common first name in French-speaking, Spanish-speaking, and German-speaking countries. It derives from the Latin name Renatus. René is the masculine form of the name (Renée being the feminine form). In some non-Francophone countries, however, there exists the habit of giving the name René (sometimes spelled without an accent) to girls as well as boys. In addition, both forms are used as surnames (family names). René as a first name given to boys in the United States reached its peaks in popularity in 1969 and 1983 when it ranked 256th. Since 1983 its popularity has steadily declined and it ranked 881st in 2016. René as a first name given to girls in the United States reached its peak in popularity in 1962 when it ranked 306th. The last year for which René was ranked in the top 1000 names given to girls in the United States was 1988. Persons with the given name * René, Duke of Anjou (1409–1480), titular king of Naples ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colloblasts
Colloblasts are unique, multicellular structures found in ctenophores. They are widespread in the tentacles of these animals and are used to capture prey. Colloblasts consist of a collocyte containing a coiled spiral filament, internal granules and other organelles. Like the cnidocytes of cnidarians, colloblasts are discharged from the animals’ tentacles, and are used to capture prey. However, unlike cnidocytes, which are venomous cells, colloblasts contain adhesives which stick to, rather than sting the prey. Form, function, and occurrence Colloblasts were first described in 1844. The apical surface of colloblasts consist of numerous cap cells that secrete eosinophilic granules that are thought to be the source of adhesion. On contact, these granules rupture, and release an adhesive substance onto the prey. The spiral filament absorbs the impact of the rupture, preventing the ensnared prey from escaping. Colloblasts are found in all ctenophores except those of the order Bero ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Heinrich Mertens
Karl Heinrich Mertens (Russian: Андрей Карлович Мертенс, 17 May 1796 – 18 September 1830 Kronstadt), was a German botanist and naturalist, and son of the botanist Franz Carl Mertens. Mertens was aboard the Russian vessel ''Senyavin'' under Captain Lieutenant Fedor Petrovich Litke with orders to explore the coasts of Russian America and Asia. This turned out to be one of the most productive voyages of discovery in the nineteenth century. Mertens, ornithologist Baron von Kittlitz, and mineralogist Alexander Postels collected and described over 1 000 new species of animal life, and some 2 500 specimens of plants, algae, and rocks. Shortly after this voyage, Litke and the ''Senyavin'' set out on another scientific expedition to Iceland, the chief scientist being Mertens who died two weeks after the expedition's return to Kronstadt. Cape Mertens (64°32’N, 172°25’W) east of the Chukotka Peninsula at the exit from the Senyavin Straits is named in his ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermaphroditic
In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many taxonomic groups of animals (mostly invertebrates) do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the female or male. For example, the great majority of tunicates, pulmonate molluscs, opisthobranch, earthworms, and slugs are hermaphrodites. Hermaphroditism is also found in some fish species and to a lesser degree in other vertebrates. Most plants are also hermaphrodites. Animal species having different sexes, male and female, are called gonochoric, which is the opposite of hermaphrodite. There are also species where hermaphrodites exist alongside males (called androdioecy) or alongside females (called gynodioecy), or all three exist in the same species (called trioecy); these three systems are so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portable Document Format
Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems.Adobe Systems IncorporatedPDF Reference, Sixth edition, version 1.23 (53 MB) Nov 2006, p. 33. Archiv/ref> Based on the PostScript language, each PDF file encapsulates a complete description of a fixed-layout flat document, including the text, fonts, vector graphics, raster images and other information needed to display it. PDF has its roots in "The Camelot Project" initiated by Adobe co-founder John Warnock in 1991. PDF was standardized as ISO 32000 in 2008. The last edition as ISO 32000-2:2020 was published in December 2020. PDF files may contain a variety of content besides flat text and graphics including logical structuring elements, interactive elements such as annotations and form-fields, layers, rich media (including video con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polar Research
''Polar Research'' is a biannual peer-reviewed scientific journal covering natural and social scientific research on the polar regions. It is published by the Norwegian Polar Institute. It covers a wide range of fields from biology to oceanography, including socio-economic and management topics. According to the ''Journal Citation Reports'', the journal has a 2014 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as ... of 1.141. References External links * Biology journals Ecology journals Geography journals Publications established in 1982 Biannual journals English-language journals 1982 establishments in Norway Antarctic research Glaciology journals {{glaciology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metridia Longa
''Metridia longa'' is a copepod found in the Arctic, the north Atlantic, the Pacific, and surrounding waters. The female has an average length of about , and the males have an average length of about . Description ''M. longa'' females have an average length of about , with an average range between about and . Males are usually smaller, with an average length of around , and a range between about . M. longa are bioluminescent, emitting light when mechanically, electrically, or chemically disturbed. This light is given through secretions containing luciferase from epidermal glands on the head and abdomen. Distribution ''M. longa'' is found in the sub-Arctic, Arctic, north Atlantic, and the Pacific, along the coast of the Americas and Asia. It has also been recorded in the Antarctic, in the Pacific Antarctic. Ecology Life history and reproduction At least in Balsfjorden, ''M. longa'' breeds from early to mid-May. It uses recently ingested food to complete and release the eggs, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calanus Hyperboreus
''Calanus hyperboreus'' is a copepod found in the Arctic and northern Atlantic. It occurs from the surface to depths of . Description The size of ''C. hyperboreus'' varies with its geography; individuals located in more temperate waters usually range from just over in more temperate waters, whereas those in colder areas usually range from . The length of its prosome can vary anywhere from . The antennae are longer or of equal length to the body. This copepod is very clear, and is generally colourless. The gut walls and posterior may be orange to dark red in colour, with a prominent lipid sac that is usually red-orange. The borders between segments have a deep red pigment. Distribution ''Calanus hyperboreus'' is found in the Arctic, north of the Bering Strait in the Pacific and the Lofoten Islands in the Atlantic. It occurs as deep as . Ecology Reproduction and life-cycle This copepod spawns between October and March (winter), using lipid-reserves to fuel reproduction (making it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calanus Glacialis
''Calanus glacialis'' is an Arctic copepod found in the north-western Atlantic Ocean, adjoining waters, and the northwestern Pacific and its nearby waters. It ranges from sea level to in depth. Females generally range from about in length, and males generally range from about in length. Description ''C. glacialis'' females generally range from about in length, and males generally range from about in length. Habitat and distribution This copepod is found in the northwestern Atlantic, the adjoining waters of the Gulf of St. Lawrence, Greenland Sea, Barents Sea, Norwegian Sea, and the central Arctic Ocean, and northwestern Pacific, in the Bering Sea and the Chukchi Sea. It ranges from sea level to in depth. Ecology Reproduction and lifecycle Depending on the conditions, it has a one to three year lifecycle. There are six nauplii and copepodite stages. Eggs are laid during the spring, with clutches typically being 40 to 80 eggs. During the summer, when temperatures are b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calanus Finmarchicus
''Calanus finmarchicus'' is a species of copepods and a part of zooplankton, which is found in enormous amounts in the northern Atlantic Ocean. Distribution and ecology ''Calanus finmarchicus'' is most commonly found in the North Sea and the Norwegian Sea. It is also found throughout the colder waters of the North Atlantic, especially off the coast of Canada, in the Gulf of Maine, and all the way up to western and northern Svalbard. ''Calanus finmarchicus'' is one of the most commonly found species of zooplankton in the subarctic waters of the North Atlantic. Sometimes confused with '' C. helgolandicus'' and '' C. glacialis'', ''C. finmarchicus'' is a large planktonic copepod whose chief diet includes diatoms, dinoflagellates, and other microplanktonic organisms. In fact, some studies have shown that heterotrophic microplankton provide a "prey resource sufficient for net lipid synthesis as well as egg production". ''C. finmarchicus'' is a key component in the food web of the No ... [...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] |
Amphipoda
Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far described. They are mostly marine animals, but are found in almost all aquatic environments. Some 1,900 species live in fresh water, and the order also includes the terrestrial sandhoppers such as ''Talitrus saltator''. Etymology and names The name ''Amphipoda'' comes, via New Latin ', from the Greek roots 'on both/all sides' and 'foot'. This contrasts with the related Isopoda, which have a single kind of thoracic leg. Particularly among anglers, amphipods are known as ''freshwater shrimp'', ''scuds'', or ''sideswimmers''. Description Anatomy The body of an amphipod is divided into 13 segments, which can be grouped into a head, a thorax and an abdomen. The head is fused to the thorax, and bears two pairs of antennae and one pair of s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
