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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 fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New England Aquarium
The New England Aquarium is a public aquarium located in Boston, Massachusetts. The species exhibited include harbor and northern fur seals, California sea lions, African and southern rockhopper penguins, giant Pacific octopuses, weedy seadragons, and thousands of saltwater and freshwater fishes. In addition to the main aquarium building, attractions at Central Wharf include the Simons Theatre and the New England Aquarium Whale Watch. More than 1.3 million guests visited the aquarium each year prior to the outbreak of the COVID-19 pandemic. The Anderson Cabot Center for Ocean Life at the New England Aquarium conducts long-running research on the North Atlantic right whale, and its Quincy Animal Care Center rescues and rehabilitates hundreds of sea turtles annually. History Boston has had multiple aquariums since the 1880s, the last before the New England Aquarium being the South Boston Aquarium at Marine Park, which closed its doors in the 1950s. As part of the city’s go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnotus Carapo
The banded knifefish (''Gymnotus carapo'') is a species of gymniform knifefish native to a wide range of freshwater habitats in South America. It is the most widespread species of '' Gymnotus'', but it has frequently been confused with several relatives, including some found outside its range like the Central America '' G. maculosus''. The English name "banded knifefish" is sometimes used for the entire genus ''Gymnotus'' instead of only the species ''G. carapo''. Range and habitat This South American fish is found in the Amazon, Orinoco and Río de la Plata basins, as well as rivers in the Guianas, northeastern Brazil (only those exiting along the country's northern coast, such as Parnaíba) and northern Argentina (south to the 36th parallel south), and in Trinidad. This makes it the most widespread species of ''Gymnotus''. ''G. carapo'' occurs in virtually any freshwater habitat in its range, such as rivers and streams (both slow- and fast-flowing), floodplains, estuaries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrial DNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. This sequencing revealed that the human mtDNA includes 16,569 base pairs and encodes 13 proteins. Since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It also permits an examination of the relatedness of populations, and so has become important in anthropology and biogeography. Origin Nuclear and mitochondrial DNA are thought to be of separate evolutionary origin, with the mtDNA being derive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrolocation
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 call ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now- extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnotus
''Gymnotus'' is a genus of Neotropical freshwater fish in the family Gymnotidae found widely in South America, Central America and southern Mexico (36th parallel south to 18th parallel north). The greatest species richness is found in the Amazon basin. They are sometimes referred to by the English name banded knifefish, although this typically is reserved for the most widespread species, '' G. carapo''. Overall ''Gymnotus'' is the most widespread genus in the order Gymnotiformes. Although not commonly eaten by humans, some members of this genus are used locally as fishing bait, and occasionally kept in aquariums. Habitat ''Gymnotus'' occur in virtually any freshwater habitat in their range, even those with little oxygen (survives by breathing air directly from the water surface), areas affected by pollution, and for a period on land if their aquatic habitat dries out. Large species tend to live near floating vegetation along the edges of large rivers or floodplains, while sma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Group
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and taxon B are sister groups to each other. Taxa A and B, together with any other extant or extinct descendants of their most recent common ancestor (MRCA), form a monophyletic group, the clade AB. Clade AB and taxon C are also sister groups. Taxa A, B, and C, together with all other descendants of their MRCA form the clade ABC. The whole clade ABC is itself a subtree of a larger tree which offers yet more sister group relationships, both among the leaves and among larger, more deeply rooted clades. The tree structure shown connects through its root to the rest of the universal tree of life. In cladistic standards, taxa A, B, and C may represent specimens, species, genera, or any other taxonomic units. If A and B are at the same taxo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term ''cladus'' (plural ''cladi'') is often used in taxonomical literature. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophorus Varii
''Electrophorus varii'' is a species of electric eel found in South America. Taxonomy It was previously classified within ''Electrophorus electricus'' when that species was considered the only one in the genus '' Electrophorus'', but a 2019 analysis described it and '' E. voltai'' as distinct species based on both their deep genetic divergences and differences in the voltage produced by each species. It is also thought to be the most basal member of the three ''Electrophorus'' species, diverging during the late Miocene. It is named in honor of American ichthyologist Richard Peter Vari. Distribution It is found throughout the lowland habitats of the Amazon Basin and in some streams in the Guiana Shield, in contrast to the other two species in the genus, which are adapted to only upland shield A shield is a piece of personal armour held in the hand, which may or may not be strapped to the wrist or forearm. Shields are used to intercept specific attacks, whether from c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophorus Voltai
''Electrophorus voltai'' is a species of electric eel found in South America. It is the strongest known bioelectricity generator in nature. Taxonomy It was previously classified within ''Electrophorus electricus'' when that species was considered the only one in the genus '' Electrophorus'', but a 2019 analysis described it and '' E. varii'' as distinct species based on both their deep genetic divergences and differences in the voltage produced by each species. It is thought to have diverged from its sister species ''E. electricus'' during the Pliocene. It is named in honor of the physicist Alessandro Volta, who is widely credited as the creator of the electric battery. Distribution It inhabits upland habitats, primarily north-flowing rivers of the Brazilian Shield, but also some south-flowing rivers of the Guiana Shield. In some streams of the Guiana Shield, it is sympatric with ''E. varii''. Description It closely resembles ''E. electricus'' but differs in skull morphol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Electricity
Static electricity is an imbalance of electric charges within or on the surface of a material or between materials. The charge remains until it is able to move away by means of an electric current or electrical discharge. Static electricity is named in contrast with current electricity, where the electric charge flows through an electrical conductor or space, and transmits energy. A static electric charge can be created whenever two surfaces contact and have worn and separated, and at least one of the surfaces has a high resistance to electric current (and is therefore an electrical insulator). The effects of static electricity are familiar to most people because people can feel, hear, and even see the spark as the excess charge is neutralized when brought close to a large electrical conductor (for example, a path to ground), or a region with an excess charge of the opposite polarity (positive or negative). The familiar phenomenon of a static shockmore specifically, an electr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amber
Amber is fossilized tree resin that has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects."Amber" (2004). In Maxine N. Lurie and Marc Mappen (eds.) ''Encyclopedia of New Jersey'', Rutgers University Press, . Amber is used in jewelry and has been used as a healing agent in folk medicine. There are five classes of amber, defined on the basis of their chemical constituents. Because it originates as a soft, sticky tree resin, amber sometimes contains animal and plant material as inclusions. Amber occurring in coal seams is also called resinite, and the term ''ambrite'' is applied to that found specifically within New Zealand coal seams. Etymology The English word ''amber'' derives from Arabic (ultimately from Middle Persian ''ambar'') via Middle Latin ''ambar'' and Middle French ''ambre''. The word was adopted in Middle English in the 14th c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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