| Electrophorus voltai | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Gymnotiformes |
| Family: | Gymnotidae |
| Genus: | Electrophorus |
| Species: | E. voltai |
| Binomial name | |
| Electrophorus voltai | |
Electrophorus voltai is a species of electric eel found in South America. It is the strongest known bioelectricity generator in nature. [2] [3]
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. [3]
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. [2] [4]
It closely resembles E. electricus but differs in skull morphology, including having a depressed skull and a wide head. It has a maximum voltage of 860 volts, making it not only the strongest bioelectricity generator of the three electric eel species, but also of any animal. [3] Males get larger than females by about 35 cm (14 in).
A 2021 study reported the first known occurrence of pack hunting by electric eels in a population of E. voltai at the mouth of the Iriri River in Brazil. [5]
Alessandro Giuseppe Antonio Anastasio Volta was an Italian physicist and chemist who was a pioneer of electricity and power and is credited as the inventor of the electric battery and the discoverer of methane. He invented the voltaic pile in 1799, and reported the results of his experiments in 1800 in a two-part letter to the president of the Royal Society. With this invention Volta proved that electricity could be generated chemically and debunked the prevalent theory that electricity was generated solely by living beings. Volta's invention sparked a great amount of scientific excitement and led others to conduct similar experiments, which eventually led to the development of the field of electrochemistry.
Luigi Galvani 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.
The Gymnotiformes are an order of teleost bony fishes commonly known as Neotropical knifefish or South American knifefish. They have long bodies and swim using undulations of their elongated anal fin. Found almost exclusively in fresh water, these mostly nocturnal fish are capable of producing electric fields to detect prey, for navigation, communication, and, in the case of the electric eel, attack and defense. A few species are familiar to the aquarium trade, such as the black ghost knifefish, the glass knifefish, and the banded knifefish.
The naked-back knifefishes are a family (Gymnotidae) of knifefishes found only in fresh waters of Central America and South America. All have organs adapted to electroreception. The family has about 43 valid species in two genera. These fish are nocturnal and mostly occur in quiet waters from deep rivers to swamps. In strongly flowing waters, they may bury themselves.
Electrophorus electricus is the best-known species of electric eel. It is a South American electric fish. Until the discovery of two additional species in 2019, the genus was classified as the monotypic, with this species the only one in the genus. Despite the name, it is not an eel, but rather a knifefish. It is considered as a freshwater teleost which contains an electrogenic tissue that produces electric discharges.
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 called weak if it is only enough to detect prey, and strong if it is powerful enough to stun or kill. The field may be in brief pulses, as in the elephantfishes, or a continuous wave, as in the knifefishes. Some strongly electric fish, such as the electric eel, locate prey by generating a weak electric field, and then discharge their electric organs strongly to stun the prey; other strongly electric fish, such as the electric ray, electrolocate passively. The stargazers are unique in being strongly electric but not using electrolocation.
Electric catfish or Malapteruridae is a family of catfishes. 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 long, but most species are far smaller.
Carlos Chagas Filho was a Brazilian physician, biologist and scientist active in the field of neuroscience. He was internationally renowned for his investigations on the neural mechanisms underlying the phenomenon of electrogenesis by the electroplaques of electric fishes. He was also an important scientific leader, being one of the founders of the Biophysics Institute of the Federal University of Rio de Janeiro and was also a president for 16 years of the Vatican's Pontifical Academy of Sciences, and president of the Brazilian Academy of Sciences (1965–1967).
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, called electrocytes, and have evolved at least six times among the elasmobranchs and teleosts. These fish use their electric discharges for navigation, communication, mating, defence, and in strongly electric fish also for the incapacitation of prey.
Paralithoxus is a genus of suckermouth armored catfishes native to tropical South America.
Anguilliformity is a morphological pattern in fishes, named for and typified by the eels. Anguilliform fish have a long, slender body, and travel by anguilliform motion. The caudal fin is often emphasized, with the other fins reduced, absent, or fused with the caudal fin. Anguilliformity has evolved independently in many groups, including among others:
Myloplus is a genus of freshwater fish in the family Serrasalmidae found in tropical and subtropical South America, where they inhabit rivers and streams. They are primarily herbivores, but also take some animal matter. Depending on the exact species, they reach up to 16–56 cm (0.5–1.8 ft) in standard length. Adult males have a double-lobed anal fin and filamentous extensions on the dorsal fin, and both sexes can be brightly colored when breeding.
Brachyhypopomus is a genus of fish in the family Hypopomidae native primarily to tropical and subtropical South America, although a single species, B. occidentalis, also occurs in Panama and Costa Rica. They are found in a wide range of static or slow-flowing freshwater habitats such as edges of rivers, streams, floodplains and swamps, but they are absent from deep river channels. There are both species in well-oxygenated waters and poorly oxygenated waters; those in the latter have adaptions that allow them to survive this like larger gills or the capability of gulping up mouthfuls of air from the water surface. Brachyhypopomus feed during the night on small invertebrates.
Hypopygus is a genus of South American gymnotiform knifefishes native to the Amazon, Orinoco and upper Paraguay basins, as well as rivers in the Guianas. They are often common, and found near submerged roots, aquatic vegetation and leaf-litter in streams, edges of rivers and floodplains. They are regularly found among vegetation in floating meadows, a habitat that often contains little oxygen, but they are well-adapted to this.
Steatogenys is a genus of gymnotiform knifefishes found in the Amazon, Orinoco and Essequibo river basins in tropical South America. The widespread and common S. elegans is found in a wide range of habitats, from the shallow essentially static waters such as floodplain lakes to fast-flowing rivers as deep as 50 m (160 ft). The two remaining species are less common and widespread, with A. duidae found mainly in small streams running through terra firme forests and S. ocellatus among submerged roots and branches in static or slow-flowing blackwater habitats. All three are regularly found among vegetation in floating meadows, a habitat that often contains little oxygen, but they are well-adapted to this.
Eigenmannia is a genus of fish in the family Sternopygidae native to tropical and subtropical South America, and Panama. They are typically found in slow-flowing streams, along the edge of large rivers, in deep river channels and in floodplains, and the genus also includes E. vicentespelaea, the only cave-adapted knifefish. Eigenmannia are often found near submerged roots, aquatic plants and floating meadows.
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.
Electrophorus varii, or Vari’s electric eel, is a species of electric eel found in South America.
Carl Sachs was a German zoologist, known for his discovery of what is now called Sachs' organ in the electric eel.
The history of bioelectricity dates back to ancient Egypt, where the shocks delivered by the electric catfish were used medicinally.
