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Amblyraja Radiata
The thorny skate (''Amblyraja radiata'') is a species of fish in the family Rajidae. This bottom-living skate lives in the North and south-eastern Atlantic Ocean in depths ranging from and water temperatures from . Species description The thorny skate reaches up to in total length and in weight. Its underside is smooth, but the upper side, as the name suggests, is very rough with many small thorns all over and 13-17 larger ones in line from the back of the head to end of the tail. The top side is brown with possibly black spots and the underside is white. It has a hard, roughly triangular snout and a tail, which is shorter than its body. It eats crustaceans, small fishes, and worms. It produces egg capsules, which are 3.4-8.9 cm long and 2.3-6.8 cm wide, which hatch outside the body. Conservation status Thorny skate are taken as bycatch in some fisheries. It is a U.S. National Marine Fisheries Servicebr>species of concern which are those species about which th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Donovan
Edward Donovan (1768 – 1 February 1837) was an Anglo-Irish writer, natural history illustrator, and amateur zoologist. He did not travel, but collected, described and illustrated many species based on the collections of other naturalists. His many books were successful in his time. He died penniless in 1837 leaving a large family destitute. Personal life Almost nothing is known about Donovan's family background, education or early life, although he is known to have been born in Cork, Ireland, and was originally surnamed O'Donovan. He is presumed to have had some independent wealth. His health declined in later years and he died penniless at his home in John Street in 1837 leaving a large family destitute. Biography Aged 21, he moved to London. He was an avid collector of natural history specimens purchased mainly at auctions of specimens from voyages of exploration. He was a fellow of the Linnean Society and the Wernerian Society which gave him access to the best collecti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skate (fish)
Skates are cartilaginous fish belonging to the family Rajidae in the superorder Batoidea of rays. More than 150 species have been described, in 17 genera.LAST, P.R. & SÉRET, B. & STEHMANN, M.F.W. & WEIGMANN, S. (2016) Skates, Family Rajidae. In: Last, P.R., White, W.T., Carvalho, M.R. de, Séret, B., Stehmann, M.F.W & Naylor, G.J.P (Eds.) Rays of the World. CSIRO Publishing, Melbourne: 204–363 Softnose skates and pygmy skates were previously treated as subfamilies of Rajidae (Arhynchobatinae and Gurgesiellinae), but are now considered as distinct families. Alternatively, the name "skate" is used to refer to the entire order of Rajiformes (families Anacanthobatidae, Arhynchobatidae, Gurgesiellidae and Rajidae). Members of Rajidae are distinguished by a stiff snout and a rostrum that is not reduced. Taxonomy and systematics Evolution Skates belong to the ancient lineage of cartilaginous fishes. Fossil denticles (tooth-like scales in the skin) resembling those of today's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amblyraja Radiata No
''Amblyraja'' is a genus of skates that primarily are found in the Atlantic, but species also occur in the East and North Pacific, the Arabian Sea, the sub-Antarctic, and off Southern Australia and New Zealand. Species Ten recognized species are placed in this genus: * ''Amblyraja badia'' (Garman, 1899) (broad skate) * ''Amblyraja doellojuradoi'' (Pozzi, 1935) (southern thorny skate) * ''Amblyraja frerichsi'' ( G. Krefft, 1968) (thickbody skate) * ''Amblyraja georgiana'' (Norman, 1938) (Antarctic starry skate) * ''Amblyraja hyperborea'' ( Collett, 1879) (Arctic skate) * ''Amblyraja jenseni'' ( Bigelow & Schroeder, 1950) (shorttail skate) * ''Amblyraja radiata'' (Donovan, 1808) (thorny skate) * ''Amblyraja reversa'' (Lloyd, 1906) (reversed skate) * ''Amblyraja robertsi'' ( Hulley, 1970) (bigmouth skate) * ''Amblyraja taaf ''Amblyraja taaf'', commonly known as the whiteleg skate or thorny skate, is a little-known skate Skate or Skates may refer to: Fish *Skate (fish), seve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Total Length
Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish measured from the tip of the snout to the posterior end of the last vertebra or to the posterior end of the midlateral portion of the hypural plate. Simply put, this measurement excludes the length of the caudal (tail) fin. * Total length (TL) is the length of a fish measured from the tip of the snout to the tip of the longer lobe of the caudal fin, usually measured with the lobes compressed along the midline. It is a straight-line measure, not measured over the curve of the body. Standard length measurements are used with Teleostei (most bony fish), while total length measurements are used with Myxini (hagfish), Petromyzontiformes (lampreys), and (usually) Elasmobranchii (sharks and rays), as well as some other fishes. Total length me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustaceans
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] |
Egg Case (Chondrichthyes)
An egg case or egg capsule, often colloquially called a mermaid's purse, is the casing that surrounds the eggs of oviparous sharks, skates and chimaeras. Egg cases typically contain one embryo, except for big skate and mottled skate egg cases, which contain up to 7 embryos. Oviparity is completely absent in the superorder Squalomorphii. Description Egg cases are made of collagen protein strands, and are often described as feeling rough and leathery. Some egg cases have a fibrous material covering the outside of the egg case, thought to aid in attachment to substrate. Egg cases without a fibrous outer layer can be striated, bumpy, or smooth and glossy. With the exception of bullhead shark eggs, egg cases are typically rectangular in shape with projections, called horns, at each corner. Depending on the species, egg cases may have one or more tendrils. Development Shortly after internal fertilization, the fertilized ovum enters the partially formed egg case located in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Marine Fisheries Service
The National Marine Fisheries Service (NMFS), informally known as NOAA Fisheries, is a United States federal agency within the U.S. Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) that is responsible for the stewardship of U.S. national marine resources. It conserves and manages fisheries to promote sustainability and prevent lost economic potential associated with overfishing, declining species, and degraded habitats. History Founded in 1871 as the U.S. Commission of Fish and Fisheries, the National Marine Fisheries Service is the oldest federal conservation and environmental research agency in the United States. The commission was formed when President Ulysses S. Grant named zoologist Spencer Fullerton Baird, United States National Museum director and assistant secretary of the Smithsonian Institution, the first commissioner of the United States Fish Commission. The commission was divided into three research categories: the study of U.S. wate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Oceanic And Atmospheric Administration
The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditions, charts the seas, conducts deep sea exploration, and manages fishing and protection of marine mammals and endangered species in the U.S. exclusive economic zone. Purpose and function NOAA's specific roles include: * ''Supplying Environmental Information Products''. NOAA supplies to its customers and partners information pertaining to the state of the oceans and the atmosphere, such as weather warnings and forecasts via the National Weather Service. NOAA's information services extend as well to climate, ecosystems, and commerce. * ''Providing Environmental Stewardship Services''. NOAA is a steward of U.S. coastal and marine environments. In coordination with federal, state, local, tribal and international authorities, NOAA manages the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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