electrocyte

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Electric Eel

The electric eel (Electrophorus electricus) is an electric fish, and the only species in its genus. Despite the name, it is not an eel, but rather a knifefish. The electric eel has three pairs of abdominal organs that produce electricity, the typical output is sufficient to stun or deter virtually any animal. They can vary the intensity of the electric discharge, using lower discharges for hunting and higher intensities for stunning prey or defending themselves. They can also concentrate the discharge by curling up and making contact at two points along its body. When agitated, they can produce these intermittent electric shocks over at least an hour without tiring. 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.

The Tennessee Aquarium in the United States is home to an electric eel that uses its electrical discharges to post from its own Twitter account. Named Miguel Wattson, the eel’s exhibit is wired to a small computer that sends out a prewritten tweet when it emits electricity at a high enough threshold.

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An excerpt from the zoological text The Hunter’s Encyclopedia of Animals (First Edition).
Glossary

A

acuomotor reflex The inflation of the gobul’s spines by taking in water and air into its elastic stomach, in order to expand its body.

aestivation (L. aestivare, from aestās, summer) A state of dormancy or torpor induced by high temperatures and arid conditions. Characterized by inactivity and a lowered metabolic rate.

agonism (Gr. agōnistēs, combatant) An offensive action or threat directed toward another organism.

ailuromorphic (Gr. aílouros, cat, + morphḗ, form) A pseudowyvern with features superficially reminiscent of felids. This includes (but is not limited to) a feathery integument analogous to a pelt, rictal bristles functionally similar to vibrissae, and obligate carnivory.

alicorn The horn on a kirin’s head, the torsion of which spirals in a counterclockwise helix. Used for facilitating electrogenesis and goring attackers. Also known as a silverhorn.

allogenic engineer Organisms that modify their biophysical environment by changing living or nonliving material.

alpenstock The barioth’s epidermal protrusions on the leading edge of the wings, knees, and lateral sides of the tail. Used for traction atop ice. Synonyms include “spine” and “spike.”

anapsid (Gr. an-, without, + apsis, arch) Amniotes in which the skull lacks temporal fenestrae, with turtles the only living representatives.

anautogeny A condition found in insects where a gravid female must feed on blood before oviposition in order for the eggs to mature.

angiosperm Seed-producing, fruit-bearing, flowering plants.

anisodactyl The arrangement of digits wherein three toes face forward and are accompanied by a single back-facing toe.

anthrax A lethal disease caused by the bacterium Bacillus anthracis. Anthrax can occur in three forms: epidermal, respiratory, and intestinal.

apex predator Carnivorous animals that occupy the highest trophic levels and have a disproportionate influence on the health of their ecosystem.

aposematism (Gr. apó, away, + sêma, sign) Any number of conspicuous auditory, visual, and olfactory antipredator adaptations which advertise that the animal is an unprofitable prey item.

aratrum (L. arātrum, plough) The cranial bone of the barroth, comprised of trabecular tissue and enlarged sinuses. This structure houses the nasal cavities and supports five dorsally-located nares. The namesake for the eponymous genus Aratrum.

B

benthos (Gr. depth of the sea) Organisms that live along the bottom of seas and lakes; adj., benthic.

bicutaneous (L. bi-, from bis, twice, + cutis, skin) The condition of an organism with an integument consisting of both keratinized scales and fur.

biological species concept A reproductive community of populations (reproductively isolated from others) that occupies a specific niche in nature.

biome (Gr. bíos, life, + -ōma, body) Communities of plants and animals characterized by climatic and soil conditions; the largest ecological unit.

C

caelincolid (L. caelum, sky, + incola, inhabitant) Any species belonging to the family Caelincolidae.

capillaturid (L. capillātūra, false hair) Any species belonging to the superfamily Capillaturoidea. Named for their plumage, which is often compared to fur on mammals. Also known as “wig wyverns.”

cathemeral An organism that demonstrates sporadic intervals of activity during the day or night.

CDIHG The Conservation Division of the International Hunters’ Guild. A group that assesses a species’ susceptibility to extinction, by monitoring populations and establishing criteria for Red List placement. Established forty years ago in response to loss of biodiversity, due to overhunting and anthropogenic ecosystem destruction.

cephalovelos (Gr. kephalé, head, + vélos, arrow) The ribbed hood structure found on the lagiacrus’ head, studded with electroreceptors on its ventral surface.

chitinase (Gr. khitṓn, tunic) Hydrolytic enzymes that break down glycosidic bonds in chitin, most commonly found in bacteria and fungi, and to a lesser extent, plants and some animals.

cloaca (L. cloāca, sewer) The posterior orifice that houses the openings for the digestive, reproductive, and urinary tracts.

conflagrant tube A mucus-lined tubular organ that connects the flame sac to an opening in the oral cavity, where the byproduct waste gas can be expelled through the mouth.

conspecific A member of the same species.

coprophagy The consumption of fecal matter.

convergent evolution See homoplasy.

crepuscular An organism that is active at twilight (dawn and dusk).

crypsis The ability of an animal to avoid detection through methods such as camouflage, nocturnality, subterranean lifestyle, and mimicry. Involves visual, olfactory, and auditory concealment.

D

dagger [†] A typographical symbol that, when used next to a name, indicates death or extinction. Also called an obelisk.

desiccation The state of extreme dryness, or the state of drying.

diapsid (Gr. di-, two, + apsis, arch) Amniotes in which the skull bears two pairs of temporal fenestrae, including birds and reptiles (barring turtles).

dog wyvern Any theropod species belonging to the family Vipracanidae. Includes the genera Magnaraptor (the greats) and Dromos (the dromes).

doloripsum One of two electric organs derived from modified nerve tissue, that runs parallel to the kirin’s cervical vertebrae.

E

ectoparasite Parasites that live on the outside of the host.

ectothermic (Gr. ektós, outside, + thermē, heat) An organism that cannot internally maintain its body temperature and must rely on external sources of heat to moderate metabolic rates. “Cold-blooded.”

elaiopteral gland (Gr. élaio, oil, + pterón, wing) An oil-secreting gland found on the inner forearm (antebrachial) of pseudowyverns in Capillaturoidea. The gland secretion is conveyed to the surface in hollow ducts, terminating at a modified spur. Used for maintenance of feather integrity, pheromone production, and waterproofing.

elder dragon A catch-all term applied to unrelated species with similar cultural and religious significance, capable of posing high-level threats to human populations. The term elder dragon is often a misnomer, used to describe very specific organisms from groups such as the squamates, cephalopods, and perissodactyls.

electrocyte Flat disc-shaped cells stacked in thousands that function by pumping sodium and potassium ions.

electrogenesis The biological generation of electricity by living organisms.

electroreception The ability to perceive ambient electrical stimuli.

electroreceptor Sense organs located in the skin used for electrolocation.

endothermic (Gr. endon, within, + thermē, heat) An organism that can internally maintain its body temperature by balancing metabolic heat production by heat loss. “Warm-blooded.”

epibiont An organism that lives on the surface of an organism, typically in a commensalistic relationship.

euryhaline A species that has a tolerance to a wide range of salinities.

exsanguination Sufficient blood loss, normally to the point of death.

extant When a species is still existing.

extinct When a species is no longer in existence. Extinction is typically decided by the death of the last individual of a species.

F

Fatalis Trinity An occult religion practiced the world over. Its chief deities are the Fatalis Brethren (species of the genus Fatum), whose worshippers believe that they are living gods reincarnated in the form of six-limbed dragons. Their Temple maxim is “Damus nostra fāta tibi.”

fire gurgling An agonistic display seen in raths and espinas. The animal will release small concentrations of methane that ignites on contact with a hypergolic chemical secreted by modified venom glands, causing tendrils of fire to ooze from its jaws.

fire regime The pattern, frequency, and intensity of wildfires prevailing within an area. Fire regimes are an integral component of fire ecology, and the interactions between fire and biotic/abiotic components of an ecosystem.

flame sac An organ connected to the stomach of raths and espinas, used for storing methane produced by microbial bacteria during the breakdown of roughage.

formic acid A carboxylic acid synthesized by ants in the family Formicidae, transmitted by sting from a modified ovipositor, spray ejected from the abdomen, or autothysis.

formicary An ants’ nest.

frenzy virus A viral disease that causes heightened aggression and acute inflammation of the brain after a period of incubation. The pathogen modifies its host’s mortality and behavior long enough to facilitate its transmission to other hosts. The shagaru magara is its primary vector.

frost sac An organ derived from a heavily-modified foregut, found in the mountain barioth. The stomach oil stored within can be ejected in a forceful spray, which then rapidly cools once exposed to frigid temperatures.

G

gaster The bulbous posterior portion of the metasoma found in hymenopterans.

Gause’s law An ecological principle which states that species competing for the same resource cannot coexist if all ecological factors are constant. If one species has an advantage over the other, then the less fit species will either undergo extinction or an evolutionary or behavioral shift toward a different niche.

Goldorolis The combined continental landmass of Goldora, Schrade, and northern Arcolis (excludes Arcolis’ southern deserts, and the Elde subcontinent). The term is a portmanteau of two of its constituent continents (Goldora and Arcolis). Analogous to Eurasia.

H

haemal arch A bony arch on the underside of tail vertebra.

heterodont (Gr. heteros, different, + odous, tooth) Having teeth differentiated into incisors, canines, and molars for different purposes.

heterogeneity A property ascribed to environments with a mix of uneven concentrations of multiple species (biological), terrain formations (geological), or environmental characteristics (meteorological).

homoplasy The emergence of a characteristic or adaptation shared by a set of species but not present in their ancestors, acquired independently by unrelated groups.

hydrophyte Plants with specific adaptations for living in aquatic or marine environments, submerged, on the surface, or in proximity to water.

hyperarousal (Gr. hupér, over, + M.E. a-, away, + A.N. reuser, rouse) A physiological self-preservation response triggered by a hormonal cascade from the sympathetic nervous system. Also called the fight-or-flight reflex.

hyperphagia (Gr. hupér, over, + -phágos, eater) A preliminary stage to heterothermy, in which an organism will gorge in order to increase its body weight. It will then subsist off of the accumulated fat reserves during its seasonal metabolic depression.

I

immunohistochemistry The process of detecting antigens in cells by observing the principle of antibodies binding to target antigens in tissue segments.

insectivory A diet of a carnivorous organism consisting chiefly of arthropods.

International Hunters’ Guild An organization whose jurisdiction supersedes that of any government. Its foremost goal is to act as a support network for hunters, while providing education, medical attention, and economic opportunity to people. Abbreviated as IHG.

J

K

keystone species A species (typically a predator) whose removal leads to reduced species diversity within the community, and the cessation of the entire ecosystem.

kinhair The soft (montane spp.) and semi-coarse (equatorial spp.) fur and hair growing on kirins.

kinsect Any number of domesticated neopteron species trained by hunters for insectry (Fr. insecterie, from insecte + -erie).

L

leviathan Any species belonging to the order Arcacollum, defined by the characteristic arched neck. The term has also been inaccurately applied to suchians such as the nibelsnarf.

lynian A member of the species Felis comes. The term is not exclusively used with actual lynians, and can refer to bipedal organisms with humanoid characteristics such as the urukis and shakalakas (relatives of the human and wyverian).

M

Mandibulaformia (L. mandibula, jaw, + fōrma, shape) A genus of flying wyverns characterized by an ossified protrusion of the jaw. While they serve no function in prey-capture or mechanical digestion, the sickle-shaped appendages are thought to be used in intraspecific communication.

membranalan (L. membrāna, skin, + āla, wing) An organism from a clade of nonavian theropods. Characterized by membraned wings (with or without feathers), bipedalism, and endothermy.

mercurid (L. mercuria, luck) Any species belonging to the family Mercuridae.

motion parallax A monocular depth cue discerned through the proximity of objects, and how fast they appear to move relative to the viewer.

N

necrosis The death of cells and/or tissues within an organism due to disease, injury, or failure of the circulatory system.

necrotoxin Toxins that cause necrosis (death) in all cells they encounter and destroy all tissue types. Transmitted through the bloodstream.

nictitating membrane A transparent or translucent third eyelid. Protects the eye from UV exposure, debris, water, snow, and impact damage.

O

olfaction The sense of smell.

ovoviviparity A mode of reproduction in which the embryos that develop inside eggs are hatched and retained within the body without a placental connection to the mother.

P

paradraconian (Gr. rapá, para, beside, + drákōn, dragon) See pseudowyvern.

patagium A membranous structure that assists an animal in gliding or flight. It is found in bats, birds, some dromaeosaurs, pterosaurs, gliding animals, true wyverns, pseudowyverns, bird wyverns, and dragons.

pelage (Fr. le pelage, fur) The fur, hair, or wool of an animal.

pentadactyl (Gr. pénte, five, + dáktulos, finger) The condition of having five digits on each limb.

phalange Digital long bones found in the hands and feet of most vertebrates.

photophore A light-emitting organ found of various marine animals that appear as luminous areas on the skin.

phylogeny (Gr. phylon, tribe, race, + geneia, origin) The origin and diversification of any taxon, or the evolutionary history of its origin and diversification, usually presented in the form of a dendrogram.

piscivory A diet of a carnivorous organism consisting chiefly of fish.

pneumatization The formation of air-filled cavities in hard tissues such as bone.

polledness The state of being hornless.

polymorphism (Gr. polús, many, + morphḗ, form) The presence in a species of more than one structural type of individual.

praesidiosaur (L. praesidium, fortress, + Gr. sauros, lizard) Any species belonging to the clade Praesidiosauria.

prenuptial hunt A behavioral assessment demonstrated by raths, in which a courting pair will hunt a prey item together. The success of the outcome determines whether or not the rathian will form a monogamous pair with the suitor rathalos.

proventriculus The narrow, glandular region of the stomach located between the crop and gizzard that uses enzymes to commence digestion, and/or stores food. Also called the foregut.

pseudowyvern (Gr. pseudḗs, lying) An organism from a clade of nonavian theropods. Characterized by membraned wings (with or without feathers), pronograde posture (quadrupedalism), and endothermy.

Q

R

receding rhampotheca A keratinized epidermal sheath found in many non-avian theropod lineages, thought to have once formed a full or semi-complete beak in ancestral species.

riparian zone The interface between land and rivers/streams, characterized by a high biodiversity of hydrophilic plants along the banks and river margin.

ruminant (L. ruminare, to chew the cud) Cud-chewing artiodactyl mammals with a complex four-chambered stomach.

S

satellite colony In hymenopterans: Small, outlying colonies staffed with soldier-caste ants that encircle the larger, central colony.

scutum (L. scūtum, shield) A chitinous extension of the pronotum, found on altaroths. Acts as an esophageal blockage when swallowed by barroths, and protects the head region when the altaroth sprays formic acid toward its anterior end.

shellshocker An electric organ derived from modified nerve tissue, located on the medial region of the lagiacrus’ spine.

symbiosis (Gr. sún, with, + bíos, life) The living together of two different species in an intimate relationship. Symbiont always benefits; host may benefit, be unaffected, or be harmed (mutualism, commensalism, and parasitism).

synapsid (G. synapsis, contact, union) An amniote lineage comprising the mammals and the ancestral mammal-like reptiles, having a skull with a single pair of temporal openings.

T

tapetum lucidum (L. tapetum, tapestry, + lūcidum, bright) A layer of tissue behind the retina in most vertebrates that reflects visible light, increasing the availability of light to photoreceptors. Increases night vision in nocturnal and deep sea organisms.

thagomizer The distinctive arrangement of four to ten horizontal spines on the tail of reptiles. Coined by cartoonist Gary Larson and perpetuated by paleontologist Ken Carpenter.

torpor A state of decreased physical activity indicated by decreased metabolic rates and internal temperature.

Trojan’s organ One of two electric organs derived from modified nerve tissue, that runs parallel to the kirin’s lumbar and thoracic vertebrae.

U

ungulate (L. ungula, hoof) Any hooved mammal.

V

vasodilation (L. vas, vessel, + -dialtion) The dilation or widening of the lumen in blood vessels. Results in decreased blood pressure.

vipracanid (L. vīpera, snake, + canis, dog) See dog wyvern.

vivernan (It. viverna, wyvern, from L. vīpera, snake) An organism from a clade of nonavian theropods, colloquially known as “true wyverns.” Characterized by featherless membraned wings, bipedalism, and ectothermy.

W

X

xerophyte (Gr. xērós, dry) Plants with specific adaptations for living in dry environments with little moisture, such as deserts or snow- and ice-covered biomes.

xyrafitperid (Gr. xyráfi, razor, + pterón, wing) Any species belonging to the family Xyrafipteridae.

Y

Z



Definitions written and compiled by the author, with some wordings borrowed from Integrated Principles of Zoology (14 ed.). Etymologies sourced from various websites, books, and online databases, including wiktionary.org.

The Electric Eel (Electrophorus electricus) is truly a wonder of the animal kingdom, and an amazing work of millions of years of evolution.

Despite its name it is in no way closely related to eels, it is a member of the Knifefish family and is the only member of its genus. The electric eel lives in fresh water in the Amazon, as well as other river basins in south america. They can grow to about 2m in length (6 and a half feet) weighing 20 kg. It can produce an electric shock of up to 600 Volts!

It produces this shock using 3 organs, the Main organ, the Hunters organ, and the Sachs organ. The total size of these 3 organs make up an amazing four fifths of the eels body! The organs are made of electrocytes, and are lined up so that a current can be passed from one organ to the next. When the eel wants to produce a shock it opens up glands in and between the organs allowing sodium ions to flow between them, creating a sudden change in potential difference (voltage.)

The shock only lasts approximately 0.2 milliseconds meaning it is not very likely to be lethal to an adult human despite it being 600 volts. That being said, it has been known to kill if the shock is, for example, directed towards the heart. 

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Of all the animals in our world, the electric eel is about as close to a pokémon as we could possibly get. These fish have special organs, like Tyanmo, which can generate electric shocks up to 600 Volts.

It’s all made possible through it’s unique nervous system. Specifically, an electric eel has three organs responsible for producing electricity, which fill up about 4/5ths of its body overall. These are called the main organ, the Hunter’s organ, and the Sach’s organ.

The organs are made of electrocytes, lined up in a way that gives them a small electric potential, such that a current could flow through them. They’re small and disc-shaped and called electrogenic cells, but think of it like a hundred tiny batteries, lined up from positive to negative end. When the eel’s nervous system gives the right signal, it sparks one into action, which quickly sets off a huge chain reaction through the eel’s entire body.

The entire process lasts less than 2 milliseconds, but can discharge 600 volts of electricity in one amp of current. They can actually control the level of discharge, choosing whether to emit a high-voltage or a low-voltage shock when appropriate. Younger eels tend to produce smaller voltages overall, which explains why Tynamos travel in packs to increase their strength.

This is insane for an animal to produce, but it’s really not that much electricity. For reference, if you wanted your arm to spasm, it would need an electric shock of 200 mA for about 50 milliseconds of exposure time. Because electric eels shock so quickly, their discharge is not enough to stun or harm a human, let alone even an arm. Not to mention the eel is shocking through water and not air, which means the energy is dissipated even more quickly.

This is why eels go undamaged in their shocks, too. Electric eels just don’t give off enough electricity to be a danger to themselves. However, much smaller prey gets much more damage. A fish 10 times smaller in length than an electric eel has about 1,000 times smaller the volume, meaning it gets the nasty end of the shock.

The majority of Tynamo’s body consists of electricity-producing organs. These organs consist of many electrogenic cells, which are lined up like tiny batteries that all fire off at once when stimulated by its nervous system.

An excerpt from the zoological text The Hunter’s Encyclopedia of Animals (First Edition).


CHAPTER II: An overview of the Moga lagiacrus

The Moga lagiacrus (Heres jormungandrii) is a large, predatory, euryhaline reptile and the sole species in the family Armutonitridae. It is informally known by a plethora of names, the most common being lord of the sea, lagia, and sea wyvern. The lagiacrus is the largest of all marine, brackish, and riparian reptiles, reaching a weight of 19 tons and 24 meters in length. These ectotherms are extremely sensitive to cold and are found exclusively in tropical climates, dispersed throughout the South Elde seas and coastlines. On land, the lagiacrus is capable of short bursts of speed at a “belly walk” of 15 mph, coupled with quick, agile torsions of its elongated body; in water, the lagiacrus has been observed swimming at 32 mph, although when cruising it will reduce its speed to a lethargic 6 mph.

Originally, lagiacrus were estimated to live 50 years, based on measurements of lamellar growth rings in bones and teeth. It was later suggested that these measurements may be an inaccurate way of gauging age. Lamellar rings reflect changes in growth rates, which correlate directly with the timeframe of wet/dry season transitions. The inaccurate reliance on seasonal changes and the fact that the innermost rings degenerate with time suggest an underestimation of age. A revised longevity is upward of 70 years.

The lagiacrus is a solitary hunter that frequents both demersal and pelagic habitats, patrolling the reefs and intertidal zones of coastlines. Lagiacrus are known to swim inland as well, and lurk within brackish mangrove swamps or freshwater jungles further upriver. Breeding takes place during the end of the dry season, in which the polygynous males mate with as many females as they can. They are apex predators, regularly killing and consuming any individual that wanders into their territory.

The seas of South Elde have been high-trafficked waters for thousands of years. Merchant ships passing blithely through the territories of lagiacrus were often sunken. Early Guild cartographers would depict horned leviathans mantled in lightning, with the oldest known examples of these maps dating back almost 3000 years. Indigenous peoples of the Moga Archipelago developed techniques for hunting and tracking lagiacrus thanks to centuries of cohabiting the same islands. One such technique involves chumming around the piers, conditioning local sharq populations to regularly visit the area. Sharqs are highly electroreceptive fish capable of perceiving the electric fields given off by lagiacrus. Upon detecting the lagiacrus, the sharqs flee, and thus act as an early warning system for the people of Moga. The lagiacrus is seen as a harbinger of earthquakes, maelstroms, and famine, with at least an eighth of all known shipwrecks attributed to it. Harbor and port towns such as Tanzia specialize in delicacies prepared from grilled and braised tails.

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Electric Eel (Electrophorus electricus)

The electric eel is a freshwater fish that is known to produce electrical shocks to stun prey and predators. This species grows up to 2 m in length and has become an apex predator in its South American range.

To generate electricity, the fish has specialised organs along the length of its body. These organs are made up of cells called “electrocytes”, which are able to produce charges of 0.15 V each. The electric eel has 5000-6000 of these cells lined up much like batteries in series to produce a cumulative shock of up to 600 V.

Despite the high voltage, the shock is unlikely to kill an adult human due to its extremely short duration of less than 2 milliseconds.

Brian Gratwicke on Flickr