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Smalltooth Stingray
The smalltooth stingray (''Dasyatis rudis'') is an obscure species of stingray in the family Dasyatidae, found in the Gulf of Guinea. It is known only from a stuffed specimen described by Albert Günther in 1870, which has since been lost. In 1970, Springer and Collette assigned a jaw, tail, and two embryos from off Sierra Leone to this species, but later investigation found that the jaw belonged to a guitarfish, and the tail and embryos to a different species, possibly ''Dasyatis hastata ''Dasyatis hastata'' is a species of stingray in the family Dasyatidae. Some authors regard this species as a synonym of the roughtail stingray The roughtail stingray (''Bathytoshia centroura'') is a species of stingray in the family Dasyati ...''. References smalltooth stingray Marine fauna of West Africa smalltooth stingray Taxa named by Albert Günther {{Rajiformes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The IUCN Red List Of Threatened Species
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit. The aim of the IUCN Red List is to convey the urgency of conservation issues to the public and policy makers, as well as help the international community to reduce species extinction. According to IUCN the formally stated goals of the Red List are to provide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partnerships. The organization is best known to the wider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Günther
Albert Karl Ludwig Gotthilf Günther Fellow of the Royal Society, FRS, also Albert Charles Lewis Gotthilf Günther (3 October 1830 – 1 February 1914), was a German-born British zoologist, ichthyologist, and herpetologist. Günther is ranked the second-most productive reptile taxonomist (after George Albert Boulenger) with more than 340 reptile species described. Early life and career Günther was born in Esslingen am Neckar, Esslingen in Swabia (Württemberg). His father was a ''Stiftungs-Commissar'' in Esslingen and his mother was Eleonora Nagel. He initially schooled at the Stuttgart Gymnasium. His family wished him to train for the ministry of the Lutheran Church for which he moved to the University of Tübingen. A brother shifted from theology to medicine, and he, too, turned to science and medicine at Tübingen in 1852. His first work was "''Ueber den Puppenzustand eines Distoma''". He graduated in medicine with an M.D. from Tübingen in 1858, the same year in which he pub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of Taxonomy (biology), 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 reproduction, produce Fertility, fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology (biology), 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 binomial nomenclature, 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 specifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myliobatiformes
Myliobatiformes () is one of the four orders of batoids, cartilaginous fishes related to sharks. They were formerly included in the order Rajiformes, but more recent phylogenetic studies have shown the myliobatiforms to be a monophyletic group, and its more derived members evolved their highly flattened shapes independently of the skates. Classification Nelson's ''Fishes of the World'' arranges the Myliobatiformes as: *Suborder Platyrhinoidei **Family Platyrhinidae (thornbacks) *Suborder Zanobatoidei **Family Zanobatidae (panrays) *Suborder Myliobatoidei (stingrays) **Superfamily Hexatrygonoidea ***Family Hexatrygonidae (sixgill stingray) **Superfamily Urolophoidea ***Family Plesiobatidae (deepwater stingray) ***Family Urolophidae (round stingrays) **Superfamily Urotrygonoidea ***Family Urotrygonidae (American round stingrays) **Superfamily Dasyatoidea ***Family Dasyatidae (whiptail stingrays) ***Family Potamotrygonidae (river stingrays) ***Family Gymnuridae ... [...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 opi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gulf Of Guinea
The Gulf of Guinea is the northeasternmost part of the tropical Atlantic Ocean from Cape Lopez in Gabon, north and west to Cape Palmas in Liberia. The intersection of the Equator and Prime Meridian (zero degrees latitude and longitude) is in the gulf. Among the many rivers that drain into the Gulf of Guinea are the Niger and the Volta. The coastline on the gulf includes the Bight of Benin and the Bight of Bonny. Name The origin of the name Guinea is thought to be an area in the region, although the specifics are disputed. Bovill (1995) gives a thorough description: The name " Guinea" was also applied to south coast of West Africa, north of the Gulf of Guinea, which became known as "Upper Guinea", and the west coast of Southern Africa, to the east, which became known as "Lower Guinea". The name "Guinea" is still attached to the names of three countries in Africa: Guinea, Guinea-Bissau, and Equatorial Guinea, as well as New Guinea in Melanesia. Geography The main river she ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm cell. The resulting fusion of these two cells produces a single-celled zygote that undergoes many cell divisions that produce cells known as blastomeres. The blastomeres are arranged as a solid ball that when reaching a certain size, called a morula, takes in fluid to create a cavity called a blastocoel. The structure is then termed a blastula, or a blastocyst in mammals. The mammalian blastocyst hatches before implantating into the endometrial lining of the womb. Once implanted the embryo will continue its development through the next stages of gastrulation, neurulation, and organogenesis. Gastrulation is the formation of the three germ layers that will form all of the different parts of the body. Neurulation forms the nervou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sierra Leone
Sierra Leone,)]. officially the Republic of Sierra Leone, is a country on the southwest coast of West Africa. It is bordered by Liberia to the southeast and Guinea surrounds the northern half of the nation. Covering a total area of , Sierra Leone has a tropical climate, with diverse environments ranging from savanna to rainforests. The country has a population of 7,092,113 as of the 2015 census. The capital and largest city is Freetown. The country is divided into five administrative regions, which are subdivided into 16 districts. Sierra Leone is a constitutional republic with a unicameral parliament and a directly elected president serving a five-year term with a maximum of two terms. The current president is Julius Maada Bio. Sierra Leone is a secular nation with the constitution providing for the separation of state and religion and freedom of conscience (which includes freedom of thoughts and religion). Muslims make up about three-quarters of the population, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guitarfish
The guitarfish, also referred to as shovelnose rays, are a family, Rhinobatidae, of rays. The guitarfish are known for an elongated body with a flattened head and trunk and small, ray-like wings. The combined range of the various species is tropical, subtropical, and warm temperate waters worldwide. Names In Australia and New Zealand, guitarfish are commonly referred to as shovelnose rays or shovelnose sharks. Description Guitarfish have a body from intermediate between those of sharks and rays. The tail has a typical shark-like form, but in many species, the head has a triangular, or guitar-like shape, rather than the disc-shape formed by fusion with the pectoral fins found in other rays. Reproduction Guitarfish are ovoviviparous; the embryo matures inside an egg within the mother until it is ready to hatch. This is typical of rays. Habitat Guitarfish are bottom feeders that bury themselves in mud or sand and eat worms, crabs, and clams. Some can tolerate salt, fresh, and b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dasyatis Hastata
''Dasyatis hastata'' is a species of stingray in the family Dasyatidae. Some authors regard this species as a synonym of the roughtail stingray The roughtail stingray (''Bathytoshia centroura'') is a species of stingray in the family Dasyatidae, with separate populations in coastal waters of the northwestern, eastern, and southwestern Atlantic Ocean. This bottom-dwelling species typica ... (''Bathytoshia centroura'').Catalog of Fishes (Online Version) . California Academy of Sciences. Retrieved on January 15, 2010. References Dasyatis Taxa ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
