#Gymnotiformes

[herpsandbirds]

Electric Eel (Electrophorus electricus), family Gymnotidae, order Gymnotiformes, found in freshwater habitats in northern South America

These predatory fish are able to stun prey using electric shocks of up to 860 volts.

They are not true eels, but are in the same order as neotropical knifefish.

photograph by Oleksandr (Alex) Zakletsky

[taxonomytournament]

Taxonomy Tournament: Fish

Gymnotiformes. This order is known as Neotropical knifefish, which have an elongated body and anal fin, and are capable of producing electric fields which they use to detect prey. Members include the electric eel and glass knifefish

Siluriformes. This order is made up of catfish, which have prominent barbels (sensory organs near the mouth) that resemble a cats whiskers.

[the-overthinktank]

YEEEAAAH GO ORDER GYMNOTIFORMES GO!!! ANAL FIN ALL THE WAY DOWN BABY!!

Was anyone going to fucking tell me that electric eels have their anus directly under their heads because their head is basically their entire main body and they're actually like 90% tail

Or was I just supposed to casually stumble across that information

[jomindraws]

Still in Superphylum Outersymmetrum

(AN1 B2) Clade: Erithrospermia

A clade of outersymmetrums that contain pointed radially symmetric forms for the entire duration of the life-cycle and contain a semi-flexible keratin shell.

PHYLUM FREESPROUT EXOTICA

Phylum containing radial point-symmetry with extrusions ending in a dermal layer, a flat underside, a single cloaca for intake and excretion, and reproduce via fragmentation or sexual diaspores.

(AN1 B2-a) Clade: Orchinadae

A clade of animals orienting their internal anatomy around a vacant cavity at the center of symmetry, used for orientation and pressure regulation, and containing a segmented brain chord.

Class Starfishkind

Class of orchinadae that have muscular tubes on ends of a variating number of rays, can detach and reattach an anterior end to and from the posterior end, and locomote via floundering, tube-based ciliary locomotion, and gymnotiform swimming; vacant cavity exposed to open water on two sides.

Class Urchinkind

Class of orchinadae that have barbed and toxic quills on the end of ray lobes, rays and ends are on non-flexible fixed positions, locomote via rolling and ciliary locomotion during adolescence and reproduction and are stationary during adulthood, vacant cavity exposed to open water on one side.

(AN1 B2-b) Clade: Gridkind

A clade of animals all containing multiple nodes of nerve nets with geometric symmetry, interlinked with collagen and elastin, and using an ammonia salt-based circulation and waste system.

Class Gridkind

Class of clade gridkind that uses full ectothermy, resides in only saltwater, and has cnidocytes lining the outer dermal layer.

(AN1 B2-c) Clade: Prototekradia

A clade of animals with a central organ lobe in a flat disk, using protruding spikes for defense, hunting, and consuming.

Class Spikediscs

Class of prototekradia that are mobile during most of their entire life, use rotational locomotion to move across the seafloor, a buoyant bladder to keep upright, and an exaggerated extension on the sagittal plane.

Class Seamines

Class of prototekradia that are mostly immoble during their life, attach themselves to the seafloor with an armored stalk, use multiple sets of buoyant bladders to raise near the surface of the sea, and a bloated spike-lined posterior end.

Yes, I'm sure you've all noticed the EXTREMELY creative names such as.... STARFISHKIND.... and URCHINKIND..... Again, these are just for namesake and I named these when I was deep in the college semester so my brain was already mush by then.... Both of those classes have a hollow center that they either use for buoyancy, orientation, wrapping around organisms, or rooting. The starfishkind actually typically look more like floundering or odd-shaped walking organisms in the sea, and only form the shape illustrated when latched to an algae/bacterial/fungal filled rock (which is a significant portion of their day lol). Urchinkind depend on the species, but the barbs on the top and sides actually act more like quills than actual urchin spikes, and organisms will typically unfurl or flatten into a bread-dough like shape when docile.

[ichthyopokethologist]

Tynamo Analysis

Uniquely for a fish pokemon, Tynamo’s entire line lacks any form of water typing, instead being purely electric. The more traditional fish body type, coupled with its white body, large eyes, and translucent fins, point to two influences: the leptocephalus, or larval stage of the true eels, and the body shape of the knifefishes (order Gymnotiformes), electric fishes most famous for the electric eel. There are also similarities to ammocoetes, the larval lamprey. Tynamo, unlike its evolutions, is primarily eel-like, not even possessing the famous teeth.

Tynamo has far weaker electrical powers than its relatives, but it makes up for weakness in lack of control. Tynamos swim in close schools, and the discharge from the agitated young can stun most larger predators, as well as killing their prey. Their whole line generates electricity from the lateral line and 3 organs just behind the mouth, though in Tynamo they reach into the abdomen and create a yellow pattern through their skin- these are the main organ, Hunter’s organ, and Sach’s organ. These organs allow them to regulate the strength of their discharges. 

Unlike their evolutions, who are capable of waddling, Tynamo are fully aquatic. They use buccal pumping and are capable of breathing, but it is unwise to keep a Tynamo out of water for long periods. If it must be done, they have to be kept wet. In Unovan caves, due to the limestone and other rocks, water is near constant and the walls are soaked; perhaps this, along with the magnetic fields they produce, is what attracts Eelektrik/Eelektross parents to such a nursery. The magnetic stones are used as suckerholds, with the young Tynamos hanging onto them, perhaps for a hold in the current or to siphon electricity. Tynamo are recorded as feeding on aquatic invertebrates such as cave Corphish*, as well as the occasional Joltik. As they approach evolution age, however, they are known to become bolder in their targets.

*Cave Corphish are morphs of the Corphish line, being far smaller and nearly white. They are blind and possess larger feelers to navigate the rivers of caverns.

[ocombatenterondonia]

Pesquisadores fazem expedição em busca de peixes-elétricos na Amazônia

Um grupo de pesquisadores inicia nesta terça-feira (20) expedição para buscar no fundo do Rio Negro, no Amazonas, em igarapés e outros ambientes na região, espécies pertencentes à ordem dos Gymnotiformes, conhecidos como peixes-elétricos. Além de identificar novas espécies, os pesquisadores pretendem contribuir para a conscientização e preservação da biodiversidade local. A expedição é parte do…

[eclecticfactoids]

Mountain goat:

"Despite its vernacular name and both genera being in the same subfamily (Caprinae), the mountain goat is not a member of Capra, the genus that includes all true goats (such as the wild goat (Capra aegagrus), from which the domestic goat is derived); rather, it is more closely allied with the other bovids known as “goat-antelopes”..." [Source: Wikipedia]

Electric eel:

"...this fish is not considered a “true” eel. While true eels are classified in the order Anguilliformes, the electric eel is actually in the order Gymnotiformes, the knife fishes." [Source: aqua.org]

King cobra:

"it is not phylogenetically a true cobra despite its common name and some resemblance" [Source: Wikipedia]

It's also not one species...

"In the 2021 study, a DNA analysis that accounted for almost the entire distribution range of king cobras identified four distinct genetic lineages. These lineages were classified as confirmed candidate species — species yet to be formally described and named." [Source: livescience.com]

Maned wolf:

"Its markings resemble those of foxes, but it is neither a fox nor a wolf. It is the only species in the genus Chrysocyon (meaning 'golden dog' in Ancient Greek" [Source: Wikipedia]

Peacock mantis shrimp:

"...these charming crustaceans aren't actually true shrimp — instead more of a distant cousin. Despite their common name, these colorful critters belong to the Stomatopoda squad, an order exclusively of mantis shrimp that either punch or spear their prey." [Source: Monterey Bay Aquarium]

Horny toad:

Also called horned lizards or horntoads, these are lizards from the genus Phrynosoma.

"Phrynosoma means 'toad-bodied'... The spines on the lizard's back and sides are modified reptile scales, which prevent water loss through the skin, whereas the horns on the head are true horns (i.e., they have a bony core)." [Source: Wikipedia]

I have just learned that Mountain Goats are NOT, in fact, actual Goats.

[irradiatedsnakes]

something i think a lot of people miss because its name is EELektross but the tynamo line is in very large part based on lampreys.

lampreys are incredibly basal (resembling the ancestral form, "primitive") vertebrates- agnathans (non-jawed) are a group of fishes that include the lampreys and the hagfish, which split off from the rest of the fish we know before moving jaws existed. they can give us a good idea of what some of the earliest vertebrates kind of looked like! they have one big sucker mouth, just like eelektrik and eelektross! (all photos via wikipedia unless otherwise mentioned)

also very of note are the dots down the side of the head on both of these- they're lamprey gill slits! unlike the operculum of most bony fishes or the multiple tall gill slits of the cartilaginous fishes, lamprey gill slits are largely circular.

now, tynamo i'm a bit split on whether it more closely resembles eel larvae (leptocephalus) or lamprey larvae (ammocoetes).

(photo via brian mccauley)

in case you didn't know, fish have larval stages! they're tiny and often weird and transparent looking. both ammoecoetes and leptocephali feed on tiny particles floating through the water (suspension feeding). i think with their white color and transparentish look, tynamo more resemble the leptocephali, but obviously with an ammocoete's jawless always-open mouth.

not relevant for our lamprey/eel discussion, but this is the larval form of the giant ocean sunfish, aka the mola mola. fucking look at it

also, a note! in addition to lampreys, the line obviously is a play on electric eels.

electric eels............are not eels.

eels are everything within the group anguilliformes. they're a big diverse group of mostly long and snake-looking fishes. this is an african conger, it's one of the prettiest eels in my opinion.

electric eels, despite the name, are indeed not eels. they're part of the gymnotiformes instead, the south american knife fish. all members of this group use electricty as a sense- they use weak electric fields kind of like an analogue to a bat's echolocation, to navigate and find food. only one genus within this group, Electrophorus, can actually shock stuff. the three species within that genus are the electric eels!

(photo via use ungulatenerd92 on zoochat)

they're funny looking guys. anyways, uh, pokemon or whatever

[encyclopika]

Animal Crossing Fish - Explained #167

Brought to you by a marine biologist who is trying not to do all the cool ones first...

CLICK HERE FOR THE AC FISH EXPLAINED MASTERPOST!

Let’s be real - not all of the fish presented in the AC franchise can be super cool. They can’t all be as awesome as the sharks or as cute as the frog or as weird and wonderful as the Barreleye. I’ve been humbled a few times by you guys, though - there have been fish that explode in popularity and I have no idea why, and then ones I think are really awesome have been mostly ignored. But I think we can all agree that today’s fish - the black ghost knifefish - is cool af, not just because of it’s looks, but because it’s electric!

The black ghost is another Pocket Camp fish that was around for a few days in October of last year (probs because it’s so perfect for Halloween) and then that was it. Pocket Camp is really kind of crappy that way, but I can’t get over the types of fish they include. If you’ve seen this thing in a pet store, you know as well as I do that they are even more wild and awesome irl.

The Black Ghost Knifefish is named to species - Apteronotus albifrons. It comes from the Order Gymnotiformes, the South American knifefish. There are about 250 species, the most famous of which is the Electric Eel (another friend who is not an eel despite its name!) These fish are almost exclusively fresh water species, except a few notable exceptions that travel into brackish water to feed. All of the Gymnotiformes move by undulating their very long anal fin that extends for much of the length of their bodies. They are also nocturnal which, makes them very interesting, but not very visible, pets. 

All Gymnotiformes fish are weakly electric (except for the electric eel, which can use its electricity to attack and defend). So, a black ghost cannot electrocute you, but it’s fascinating what they can do. Most knifefish use their electricity to sense their environments, called electrolocation. It’s just like echolocation in dolphins, except these are electrical signals, not auditory. The black ghost sends out pulsing electric signals and then can determine its environment by the electrical change it senses in its electrosensors, which are like little pores along its body. The amplitude and timing of the returning signals tells the black ghost about how its environment is shaped. So, even in the dark, the black ghost can “see” fairly well. The electric charge is generated in an electric organ found in the tail which houses a small group of cells that can discharge electricity at frequencies close to 2000 times a second - the fastest in the animal kingdom!

Black ghosts also use this electricity to communicate with one another and can tell each other apart by sex, age, and even subordination via the frequency of their electric pulses. Needless to say, much of the black ghost’s brain is dedicated to reading its own and other ghost’s electric signals!

And there you have it! Fascinating stuff, no?   

[newtsnaturethings]

Electric eels aren’t actually eels.

Nope they are actually part of the order Gymnotiformes (eels are part of order Anguiliformes) and are more closely related to catfish and carp.

Electric eels live exclusively in fresh water ecosystems in South America, whereas most eels live in marine ecosystem. Electric eels can also breath air for some reason, because I guess being about to generate 600 volts of electricity wasn’t intimidating enough.

Oh yeah they can create electricity. That’s a thing.

They can grow to be 9 ft/ 3 m long (what) and weigh up to 50 lbs/ 23 kg.

In summary electric eels are basically stretched out, tube-shaped catfish that can shock their prey like Pikachu.

[dia-bolical]

straight friend groups: chad, jessica, veronica, michael, ron

gay friend groups: anguilliform swimmer, subcarangiform swimmer, carangiform swimmer (they're subcarangiform's partner), thunniform swimmer, ostraciiform swimmer, amiiform swimmer, gymnotiform swimmer, balistiform swimmer, tetraodontiform swimmer, rajiform swimmer (non binary), diodontiform swimmer and labriform swimmer (only one who knows how to drive)

[herpsandbirds]

Electric Eel (Electrophorus electricus), family Gymnotidae, order Gymnotiformes, found in freshwater habitats in northern South America

These predatory fish are able to stun prey using electric shocks of up to 860 volts.

They are not true eels, but are in the same order as neotropical knifefish.

photograph via: Long Island Aquarium

[nuadox]

eDNA sequencing will enable scientists to explore piscine diversity in the Amazon without catching fish

- By André Julião , Agência FAPESP - 

A scientific expedition in the Javari River basin on the border between Brazil, Colombia and Peru has shown use of environmental DNA sequencing to be feasible to investigate fish diversity in the Amazon. The eDNA method consists of extracting molecules of DNA present in water samples and identifying the species to which they belong by means of genetic markers.

An article on the research published in the journal Scientific Reports also discusses the limitations of the technique for the study of environments as highly diverse as Amazonia.

“We need to continue catching and identifying animals by traditional methods in order to create libraries of genetic material. They will serve as a reference for comparing whatever is found in water samples. As the technique advances, in a few years we may be able to know about all the fish species present in a place without catching them,” said Carlos David de Santana, a research associate at the Smithsonian Institution’s National Museum of Natural History in the United States and first author of the article.

The study was part of the project “Diversity and evolution of Gymnotiformes”, supported by FAPESP and led by Naércio Menezes, a professor at the University of São Paulo’s Zoology Museum (MZ-USP) in Brazil. “The extraction of DNA from water samples creates expectations that are highly favorable to protection of the environment, as the usual methods for collecting samples of aquatic animals include the use of nets and other fishing gear with a negative impact,” said Menezes, a co-author of the article.

The group of researchers spent 18 days on the Javari River, collecting water samples at three of 46 locations where they collected fish specimens. The number of species represented reached the surprising total of 443, and 60 were new to science.

At the sites from which water for eDNA analysis was collected, 201 species were caught using traditional methods. However, only 58, or 26% of the total, were identified with precision at the species level from analysis of the eDNA.

“A possible explanation is lack of reference genetic material in databases that can be used for purposes of comparison. In addition, many species in these locations are entirely new and have never been identified before using conventional techniques,” said Gislene Torrente-Vilara, a professor at the Federal University of São Paulo’s Institute of Marine Sciences (IMAR-UNIFESP) in Santos and also a co-author of the article.

Torrente-Vilara led the expedition as part of the Amazon Fish project, an international collaboration that was supported by FAPESP and resulted in a new understanding of the distribution of fish species in the region (more at: agencia.fapesp.br/31956). 

DNA in 100 milliliters of water

To sequence the eDNA, the researchers first collected 100 milliliter surface water samples at three predetermined locations. The samples were filtered and mixed with a solution to prevent degradation of the eDNA.

The 12S mitochondrial RNA gene is the marker most widely used worldwide to identify fish species from eDNA. To find this small piece of genetic code in the water samples, the researchers used DNA extraction kits designed for analysis of both blood and tissue. Excrement and animal parts present in the water can be “captured” by the technique.

However, 12S is a slowly evolving piece of genetic code and might not be sufficient to identify all fish specimens at the species level because many species in the Amazon diverged more than once millions of years ago (recently in evolutionary terms).

For the same reason, eDNA sequencing provided a precise portrait only of the orders represented in the samples. It also differentiated the communities that live in large rivers from those that inhabit small streams deep in the forest (igarapés).

The Amazon basin is home to the highest freshwater fish diversity in the world, with more than 2,700 scientifically described species belonging to 18 orders, 60 families, and over 500 genera. 

“Even with an adequate library, it would be very difficult to identify everything at the species level with just this marker,” Santana said. “Two electric eels that diverged recently, for example, Electrophorus voltai and E. electricus, could appear to be a single species” (more about electric eels at: agencia.fapesp.br/31386). 

The researchers expect the technique to improve enough in the years ahead for more than one DNA sample to be sequenced simultaneously, so that species can be defined precisely. Until then it will be necessary to create genetic reference libraries, and Santana plans to catalog genetic material from at least all fish families and most fish genera in the Amazon.

In this context, the authors stress that natural history museums are ideal institutions for creating genetic reference libraries and storing environmental samples. As technologies advance, the material deposited can be sequenced with growing precision.

“Museums conserve samples of biodiversity for a very long time and make them available for study by future generations. To keep genetic material viable for such long periods, however, they need to implement cryogenic facilities, or significantly expand the ones they have, rearranging their physical layout and acquiring massive amounts of equipment, such as ultra low temperature freezers and liquid nitrogen tanks,” said Aléssio Datovo, another co-author of the article and fish curator at MZ-USP, the first institution in Brazil to collect samples of eDNA.

The technique can also be used for environmental monitoring, and even to engage schools and riverine communities in conservation initiatives via citizen science programs (more at: agencia.fapesp.br/37085). 

The article “The critical role of natural history museums in advancing eDNA for biodiversity studies: a case study with Amazonian fishes” is at: www.nature.com/articles/s41598-021-97128-3.

 This text was originally published by FAPESP Agency according to Creative Commons license CC-BY-NC-ND. Read the original here.

--

Read Also

Predicting the biodiversity of rivers

[explorerrowan]

Huh. Had to look it up. The king cobra is its own genus, Ophiophagus, and genetic analysis says it's more closely related to the mambas of Africa than it is to any of the true cobras in the Naja genus. Similarly, electric eels are in the genus Electrophorus, in the knifefish order Gymnotiformes, which makes them closer related to catfish than the true eels over in the genus Anguilliformes.

— Paige Lewis, “The Terre Haute Planetarium Rejected My Proposal” from Space Struck

[hecate1725]

Electric eel

Scientific Name:

Electrophorus electricus

Taxonomic Classification:

Kingdom:Animalia Phylum:Chordata Class:Actinopterygii Order:Gymnotiformes Family:Gymnotidae Genus:Electrophorus Species:E. electricus

Nutritional Requirement:

Electric eels feed on invertebrates, although adult eels may also consume fish and small mammals, such as rats. First-born hatchlings eat other eggs and embryos from later clutches. The juveniles eat invertebrates, such as shrimp and crabs.

growth and development:

The evaluation of the growth patterns and reproductive strategies of fish species are vitally important for the understanding of their biology and the management of stocks. The present study focused on the Amazonian electric eel (Electrophorus electricus), which is capable of producing an electrical shock

Behavior:

Electric eels inhabit fresh waters of the Amazon and Orinoco River basins in South America, in floodplains, swamps, creeks, small rivers, and coastal plains. They often live on muddy bottoms in calm or stagnant waters.

Reproduction:

The electric eel is known for its unusual breedingbehavior. In the dry season, a male eel makes a nest from his saliva into which the female lays her eggs. As many as 3,000 young will hatch from the eggs in one nest. Maleelectric eels are much smaller than the females.

Evolutionary origins:

They took took DNA samples from cells in its electric organ—called electrocytes—and compared it to the DNA from other tissue, including its muscle, kidney, and nerve cells. ... In muscle cells, which electrocytes evolved from, these genes control the ability to contract. In the eel, these genes were highly suppressed.

Habitat:

Electric eels inhabit fresh waters of the Amazon and Orinoco River basins in South America, in floodplains, swamps, creeks, small rivers, and coastalplains. They often live on muddy bottoms in calm or stagnant waters.

works cited:

https://www.google.com/search?rlz=1C1CHBF_enUS777US780&biw=1600&bih=745&ei=PPDsWtyMNarcjwTaw4GgDw&q=electric+eel+growth+and+development&oq=electric+eel+growth+and+&gs_l=psy-ab.1.0.33i160k1.35804.44813.0.46356.17.16.0.0.0.0.2126.4464.0j7j7-1j0j1.9.0....0...1.1.64.psy-ab..8.9.4461...0j0i7i30k1j0i20i263k1j0i30k1j0i10i30k1j0i5i30k1j0i22i30k1.0.m3Yv1xbSVg4

https://www.google.com/search?rlz=1C1CHBF_enUS777US780&biw=1600&bih=745&ei=bfDsWtjcO6jojwTjmoq4BA&q=electric+eel+behavior&oq=electric+eel+behavior&gs_l=psy-ab.3..0l2j0i22i30k1l2.118837.121423.0.121830.10.9.1.0.0.0.159.1026.0j8.8.0....0...1.1.64.psy-ab..1.9.1030....0.kuaSDeBZq4c

[typhlonectes]

Banded Knifefish (Gymnotus carapo) from freshwater ecosystems of tropical South America.

“ This species, as with all Gymnotiformes, has the capability to generate weak electric charges, and then measure the disturbance in the field of electricity created. This system is used for navigation by the fish...” (Wikipedia)

photograph by José Cezar Nolasco | EOL CC