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Electrocytes
file:Elektroplax_Rochen.png, An electric ray (Torpediniformes) showing location of paired electric organs in the head, and electrocytes stacked within it In biology, the electric organ is an organ that an electric fish uses to create an electric field. Electric organs are derived from modified muscle or in some cases nerve tissue, and have evolved at least six times among the Elasmobranchii, elasmobranchs and teleosts. These fish use their electric discharges for animal navigation, navigation, communication, mating, defence in animals, defence, and in strongly electric fish also for the incapacitation of Predation, prey. The electric organs of two strongly electric fish, the Electric ray, torpedo ray and the electric eel were first studied in the 1770s by John Walsh (scientist), John Walsh, Hugh Williamson, and John Hunter (surgeon), John Hunter. Charles Darwin used them as an instance of convergent evolution in his 1859 ''On the Origin of Species''. Modern study began with Hans L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Eel
The electric eels are a genus, ''Electrophorus'', of neotropical freshwater fish from South America in the family Gymnotidae. They are known for their ability to stun their prey by generating electricity, delivering shocks at up to 860 volts. Their electrical capabilities were first studied in 1775, contributing to the invention in 1800 of the electric battery. Despite their name, electric eels are not closely related to the true eels (Anguilliformes) but are members of the electroreceptive knifefish order, Gymnotiformes. This order is more closely related to catfish. In 2019, electric eels were split into three species: for more than two centuries before that, the genus was believed to be monotypic, containing only ''Electrophorus electricus.'' They are nocturnal, air-breathing animals, with poor vision complemented by electrolocation; they mainly eat fish. Electric eels grow for as long as they live, adding more vertebrae to their spinal column. Males are larger than fem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Fish
An electric fish is any fish that can generate electric fields. Most electric fish are also electroreceptive, meaning that they can sense electric fields. The only exception is the stargazer family. Electric fish, although a small minority, include both oceanic and freshwater species, and both cartilaginous and bony fishes. Electric fish produce their electrical fields from an electric organ. This is made up of electrocytes, modified muscle or nerve cells, specialized for producing strong electric fields, used to locate prey, for defence against predators, and for signalling, such as in courtship. Electric organ discharges are two types, pulse and wave, and vary both by species and by function. Electric fish have evolved many specialised behaviours. The predatory African sharptooth catfish eavesdrops on its weakly electric mormyrid prey to locate it when hunting, driving the prey fish to develop electric signals that are harder to detect. Bluntnose knifefishes produce an el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predation
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predators may actively search for or pursue prey or wait for it, often concealed. When prey is detected, the predator assesses whether to attack it. This may involve ambush or pursuit predation, sometimes after stalking the prey. If the attack is successful, the predator kills the prey, removes any inedible parts like the shell or spines, and eats it. Predators are adapted and often highly specialized for hunting, with acute senses such as vision, hearing, or smell. Many predatory animals, both vertebrate and inv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Eel's Electric Organs
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations. Various common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others. The presence of an electric charge, which can be either positive or negative, produces an electric field. The movement of electric charges is an electric current and produces a magnetic field. When a charge is placed in a location with a non-zero electric field, a force will act on it. The magnitude of this force is given by Coulomb's law. If the charge moves, the electric field would be doing work on the electric charge. Thus we can speak of electric potential at a certain point in space, which is equal to the work done by an external agent in carrying a unit of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Ray
The electric rays are a group of rays, flattened cartilaginous fish with enlarged pectoral fins, composing the order Torpediniformes . They are known for being capable of producing an electric discharge, ranging from 8 to 220 volts, depending on species, used to stun prey and for defense. There are 69 species in four families. Perhaps the best known members are those of the genus ''Torpedo''. The torpedo undersea weapon is named after it. The name comes from the Latin , 'to be stiffened or paralyzed', from the effect on someone who touches the fish. Description Electric rays have a rounded pectoral disc with two moderately large rounded-angular (not pointed or hooked) dorsal fins (reduced in some Narcinidae), and a stout muscular tail with a well-developed caudal fin. The body is thick and flabby, with soft loose skin with no dermal denticles or thorns. A pair of kidney-shaped electric organs are at the base of the pectoral fins. The snout is broad, large in the Narcinidae, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroreception And Electrogenesis
Electroreception and electrogenesis are the closely-related biological abilities to perceive electrical stimuli and to generate electric fields. Both are used to locate prey; stronger electric discharges are used in a few groups of fishes to stun prey. The capabilities are found almost exclusively in aquatic or amphibious animals, since water is a much better conductor of electricity than air. In passive electrolocation, objects such as prey are detected by sensing the electric fields they create. In active electrolocation, fish generate a weak electric field and sense the different distortions of that field created by objects that conduct or resist electricity. Active electrolocation is practised by two groups of weakly electric fish, the Gymnotiformes (knifefishes) and the Mormyridae (elephantfishes), and by ''Gymnarchus niloticus'', the African knifefish. An electric fish generates an electric field using an electric organ, modified from muscles in its tail. The field is cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Catfish
Electric catfish or Malapteruridae is a family of catfishes (order Siluriformes). This family includes two genera, '' Malapterurus'' and ''Paradoxoglanis'', with 21 species. Several species of this family have the ability to generate electricity, delivering a shock of up to 350 volts from its electric organ. Electric catfish are found in tropical Africa and the Nile River. Electric catfish are usually nocturnal and carnivorous. Some species feed primarily on other fish, incapacitating their prey with electric discharges, but others are generalist bottom foragers, feeding on things like invertebrates, fish eggs, and detritus. The largest can grow to about 1.2 meters (3 ft) long, but most species are far smaller. Description The Malapteruridae are the only group of catfish with well-developed electrogenic organs; however, electroreceptive systems are widespread in catfishes. The electrogenic organ is derived from anterior body musculature and lines the body cavity. Electric catf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hugh Williamson
Hugh Williamson (December 5, 1735 – May 22, 1819) was an American Founding Fathers of the United States, Founding Father, physician, and politician. He is best known as a signatory to the U.S. Constitution, and for representing North Carolina at the Philadelphia Convention, Constitutional Convention. Williamson was a scholar of international renown. His erudition had brought him into contact with some of the leading intellectuals of the Patriot (American Revolution), Patriot cause and, in turn, with the ferment of political ideas that eventually found expression in the Constitution. During the American Revolution, Williamson contributed his talents as physician and natural scientist to the American war effort. His experiences in that preeminent event of his generation transformed the genial scholar into an adroit politician and a determined leader in the campaign for effective national government. This leadership was evident not only at the Convention in Philadelphia but also, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Society
The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, recognising excellence in science, supporting outstanding science, providing scientific advice for policy, education and public engagement and fostering international and global co-operation. Founded on 28 November 1660, it was granted a royal charter by King Charles II as The Royal Society and is the oldest continuously existing scientific academy in the world. The society is governed by its Council, which is chaired by the Society's President, according to a set of statutes and standing orders. The members of Council and the President are elected from and by its Fellows, the basic members of the society, who are themselves elected by existing Fellows. , there are about 1,700 fellows, allowed to use the postnominal title FRS (Fellow of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luigi Galvani
Luigi Galvani (, also ; ; la, Aloysius Galvanus; 9 September 1737 – 4 December 1798) was an Italian physician, physicist, biologist and philosopher, who studied animal electricity. In 1780, he discovered that the muscles of dead frogs' legs twitched when struck by an electrical spark. This was an early study of bioelectricity, following experiments by John Walsh and Hugh Williamson. Early life Luigi Galvani was born to Domenico Galvani and Barbara Caterina Foschi, in Bologna, then part of the Papal States. Domenico was a goldsmith. Galvani then began taking an interest in the field of "medical electricity". This field emerged in the middle of the 18th century, following electrical researches and the discovery of the effects of electricity on the human body by scientists including Bertrand Bajon and Ramón M. Termeyer in the 1760s, and by John Walsh and Hugh Williamson in the 1770s. Galvani vs. Volta Alessandro Volta, a professor of experimental physics in the Unive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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