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Thorny Skate
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 ... [...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 collectio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish
A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can be grouped into the more basal (phylogenetics), basal jawless fish and the more common jawed fish, the latter including all extant taxon, living cartilaginous fish, cartilaginous and bony fish, as well as the extinct placoderms and acanthodians. In a break to the long tradition of grouping all fish into a single Class (biology), class (Pisces), modern phylogenetics views fish as a paraphyletic group. Most fish are ectotherm, cold-blooded, their body temperature varying with the surrounding water, though some large nekton, active swimmers like white shark and tuna can hold a higher core temperature. Many fish can communication in aquatic animals#Acoustic, communicate acoustically with each other, such as during courtship displays. The stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skate (fish)
Skates are Chondrichthyes, cartilaginous fish belonging to the family (biology), family Rajidae in the superorder Batoidea of Ray (fish), rays. More than 150 species have been described, in 17 genera. Arhynchobatidae, Softnose skates and Gurgesiellidae, 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 (anatomy), rostrum that is not reduced. Taxonomy and systematics Evolution Skates belong to the ancient lineage of cartilaginous fishes. Fossil Dermal denticle, denticles (tooth-like scales in the skin) resembling those of today's chondrichthyans date at least as far back as the Ordovician, with the oldest unambiguous fossils of cartilaginous fish dating from the m ... [...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 Eight recognized species are placed in this genus: * '' 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 Donovan Phillips Leitch (born 10 May 1946), known mononymously as Donovan, is a Scottish musician, songwriter and record producer. He emerged from the British folk scene in early 1965 and subsequently scored multiple international hit singles ..., 1808) (thorny skate) * '' Amblyraja reversa'' ( Lloyd, 1906) (reversed skate) * '' Amblyraja taaf'' ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Total Length
Fish measurement is the measuring of individual fish and various parts of their anatomies, for data used in many areas of ichthyology, including taxonomy and fishery 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. 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 (shark Sharks are a group of elasmobranch cartilaginous fish characterized by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustaceans
Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of Arthropod, arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic animal, aquatic arthropods including decapoda, decapods (shrimps, prawns, crabs, lobsters and crayfish), ostracoda, seed shrimp, branchiopoda, branchiopods, argulidae, fish lice, krill, remipedes, isopods, barnacles, copepods, Mysida, opossum shrimps, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the Hexapoda, hexapods (insects and entognathans) emerged deep in the Crustacean group, with the completed pan-group referred to as Pancrustacea. The three classes Cephalocarida, Branchiopoda and Remipedia are more closely related to the hexapods than they are to any of the other crustaceans (oligostracans and multicrustaceans). The 67,000 described spec ... [...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 chondrichthyans. Living chondricthyans that produce egg cases include some 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 Squalomorphi. Egg cases are also thought to have been produced by some extinct chondrichthyan groups, such as hybodonts and xenacanths. 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 eac ... [...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. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Oceanic And Atmospheric Administration
The National Oceanic and Atmospheric Administration (NOAA ) is an American scientific and regulatory agency charged with Weather forecasting, forecasting weather, monitoring oceanic and atmospheric conditions, Hydrography, charting the seas, conducting deep-sea exploration, and managing fishing and protection of marine mammals and endangered species in the US exclusive economic zone. The agency is part of the United States Department of Commerce and is headquartered in Silver Spring, Maryland. History NOAA traces its history back to multiple agencies, some of which are among the earliest in the federal government: * United States Coast and Geodetic Survey, formed in 1807 * National Weather Service, Weather Bureau of the United States, formed in 1870 * United States Fish Commission, Bureau of Commercial Fisheries, formed in 1871 (research fleet only) * NOAA Commissioned Corps, Coast and Geodetic Survey Corps, formed in 1917 The most direct predecessor of NOAA was the Enviro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
