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Pleurotomella Annulata
''Pleurotomella annulata'' is a species of sea snail, a marine gastropod mollusk in the family Raphitomidae. Description The length of the shell attains 5.2 mm. Distribution This marine species occurs in the Davis Sea and the Weddell Sea, Antarctica. References * Dell, R.K. 1990. ''Antarctic Mollusca: with special reference to the fauna of the Ross Sea.'' Bulletin of the Royal Society of New Zealand 27: 1–311 * Engl, W. 2012. ''Shells of Antarctica.'' Hackenheim : Conchbooks 402 pp. External links Die antarktischen Schnecken und Muscheln In: Deutsche Südpolar-Expedition 1901-1903 (Erich von Drygalski Erich Dagobert von Drygalski (; February 9, 1865 – January 10, 1949) was a German geographer, geophysicist and polar scientist, born in Königsberg, East Prussia. Between 1882 and 1887, Drygalski studied mathematics and natural science at t ..., E.v. ed.), vol. 8, No. 5, Georg Reimer, Berlin. Kantor Y.I., Harasewych M.G. & Puillandre N. (2016). A critical review of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Snail
Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the absence of a visible shell. Definition Determining whether some gastropods should be called sea snails is not always easy. Some species that live in brackish water (such as certain neritids) can be listed as either freshwater snails or marine snails, and some species that live at or just above the high tide level (for example species in the genus '' Truncatella'') are sometimes considered to be sea snails and sometimes listed as land snails. Anatomy Sea snails are a very large group of animals and a very diverse one. Most snails that live in salt water respire using a gill or gills; a few species, though, have a lung, are intertidal, and are active only at low tide when they can move around in the air. These air-breathing species includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs. The class Gastropoda contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Late Cambrian. , 721 families of gastropods are known, of which 245 are extinct and appear only in the fossil record, while 476 are currently extant with or without a fossil record. Gastropoda (previously known as univalves and sometimes spelled "Gasteropoda") are a major part of the phylum Mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail and slug species. The anatomy, behavior, feeding, and re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusk
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raphitomidae
Raphitomidae is a family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families". ''Malacologia'' 47(1-2). . 397 pp. Bouchet, Kantor ''et al''. elevated in 2011 the subfamily Raphitominae (which at that point had been placed in the family Conidae) to the rank of family. This was based on a cladistical analysis of shell morphology, radular characteristics, anatomical characters, and a dataset of molecular sequences of three gene fragments. The family was found to be monophyletic. Description The Raphitomidae is the largest, most diverse and most variable taxon in the Conoidea, with the greatest number of species and the largest ecological range (from the tropics to the pole) and largest vertical range (intertidal to hadal depths). The shells of species in the Raphitomidae are very variable in shape (buccinoid to ovate, elongate-fusiform, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Davis Sea
Davis Sea is an area of the sea along the coast of East Antarctica between West Ice Shelf in the west and the Shackleton Ice Shelf in the east, or between 82° and 96°E. The name "Davis Sea" appears in most leading geographically authoritative publications such as the 2014 10th edition World Atlas from the National Geographic Society and the 2014 12th edition of the ''Times Atlas of the World'', unlike neighboring proposed water body names such as the Russian-proposed Cooperation Sea to the west. According to the ''Great Soviet Encyclopedia'', it stretches from 87°E to 98°E, and is up to deep. Its area is given as only . Other authorities such as National Geographic assign it a much smaller extent. The sea borders the Leopold and Astrid Coast portion of Princess Elizabeth Land, then Kaiser Wilhelm II Land, Pravda Coast and Queen Mary Land. The never-approved 2002 draft fourth edition of ''Limits of Oceans and Seas'' identifies that the Tryoshnikova Gulf (named after ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weddell Sea
The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha Coast, Queen Maud Land. To the east of Cape Norvegia is the King Haakon VII Sea. Much of the southern part of the sea is covered by a permanent, massive ice shelf field, the Filchner-Ronne Ice Shelf. The sea is contained within the two overlapping Antarctic territorial claims of Argentine Antarctica, the British Antarctic Territory, and also resides partially within the Antarctic Chilean Territory. At its widest the sea is around across, and its area is around . Various ice shelves, including the Filchner-Ronne Ice Shelf, fringe the Weddell sea. Some of the ice shelves on the east side of the Antarctic Peninsula, which formerly covered roughly of the Weddell Sea, had completely disappeared by 2002. The Weddell Sea has been deemed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First German Antarctica Expedition
The ''Gauss'' expedition of 1901–1903 (also known as the ''Deutsche Südpolar-Expedition 1901–1903)'' was the first German expedition to Antarctica. It was led by geologist Erich von Drygalski in the ship , named after the mathematician and physicist Carl Friedrich Gauss. Voyage Drygalski led the first German South Polar expedition with the ship ''Gauss'' to explore the unknown area of Antarctica lying south of the Kerguelen Islands. The expedition started from Kiel on 11 August 1901. Expedition A small party of the expedition was also stationed on the Kerguelen Islands, while the main party proceeded further south. Erich von Drygalski paid a brief call to Heard Island and provided the first comprehensive scientific information on the island's geology, flora, and fauna. Despite their entrapment in the ice for nearly 14 months (until February 1903), new territory was discovered: Kaiser Wilhelm II Land and its volcano—Gaussberg Gaussberg (or Schwarzen Berg, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erich Von Drygalski
Erich Dagobert von Drygalski (; February 9, 1865 – January 10, 1949) was a German geographer, geophysicist and polar scientist, born in Königsberg, East Prussia. Between 1882 and 1887, Drygalski studied mathematics and natural science at the University of Königsberg, Bonn, Berlin and Leipzig. He graduated with a doctorate thesis about ice shields in Nordic areas. Between 1888 and 1891, he was an assistant at the Geodetic Institute and the Central Office of International Geodetics in Berlin. Drygalski led two expeditions between 1891 and 1893, which were supplied by the Society for Geoscience of Berlin. One expedition wintered during the winter between 1892 and 1893 in Western Greenland. He habilitated 1889 for geography and geophysics with the collected scientific evidence. In 1898, Drygalski became associate professor and 1899 extraordinary professor for geography and geophysics in Berlin. ''Gauss'' expedition Drygalski led the first German South Polar expedition wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleurotomella
''Pleurotomella'' is a genus of sea snails, marine gastropod mollusks in the family Raphitomidae. Description (Original description by Verrill) As at present understood, this genus is intended to include those species which have a rather broad and very distinct subsutural band, crossed by excurved lines of growth corresponding to the form of the posterior sinus of the lip, which is situated a little below the suture and is always pretty well-developed, but is sometimes broad and shallow, and at other times narrower and very deep. The outer lip is always thin and sharp, without any appearance of a varix, nor is there any deposit of callus on the body whorl, in front of the aperture. The siphonal canal is well developed, generally constricted at the base and somewhat elongated, and usually but slightly curved. In a few of the species, doubtfully referred to hie genus, it is short and wide. The columella-margin is more or less sinuous. The protoconch differs in sculpture, and u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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