The hellbender (''Cryptobranchus alleganiensis''), also known as the hellbender salamander, is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

of aquatic

giant salamander The Cryptobranchidae are a family of fully aquatic salamanders commonly known as the giant salamanders. They include the largest living amphibians. The family is native to China, Japan, and the eastern United States. They constitute one of two li ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to the eastern and central United States. It is the largest salamander in

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the C ...

. A member of the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Ideall ...

Cryptobranchidae The Cryptobranchidae are a family of fully aquatic salamanders commonly known as the giant salamanders. They include the largest living amphibians. The family is native to China, Japan, and the eastern United States. They constitute one of two li ...

, the hellbender is the only

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extin ...

member of the genus ''Cryptobranchus''. Other closely related salamanders in the same family are in the genus ''

Andrias ''Andrias'' is a genus of giant salamanders. It includes the largest salamanders in the world, with ''A. japonicus'' reaching a length of , and ''A. sligoi'' reaching . While extant species are only known from East Asia, several extinct species i ...

'', which contains the

Japanese Japanese may refer to: * Something from or related to Japan, an island country in East Asia * Japanese language, spoken mainly in Japan * Japanese people, the ethnic group that identifies with Japan through ancestry or culture ** Japanese diaspor ...

and

Chinese giant salamander The Chinese giant salamander (''Andrias davidianus'') is one of the largest salamanders and one of the largest amphibians in the world.cutaneous gas exchange Cutaneous respiration, or cutaneous gas exchange (sometimes called, skin breathing), is a form of respiration in which gas exchange occurs across the skin or outer integument of an organism rather than gills or lungs. Cutaneous respiration may be ...

through

capillaries A capillary is a small blood vessel from 5 to 10 micrometres (μm) in diameter. Capillaries are composed of only the tunica intima, consisting of a thin wall of simple squamous endothelial cells. They are the smallest blood vessels in the body: ...

found in its

dorsoventral Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pr ...

skin folds), and fills a particular

niche Niche may refer to: Science * Developmental niche, a concept for understanding the cultural context of child development *Ecological niche, a term describing the relational position of an organism's species * Niche differentiation, in ecology, th ...

—both as a

predator 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 t ...

and

prey 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 ...

—in its

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...

, which either it or its ancestors have occupied for around 65 million years. The species is listed as Vulnerable on the

IUCN Red List of Threatened Species The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biolog ...

Etymology

The origin of the name "hellbender" is unclear. The

Missouri Department of Conservation The Missouri Department of Conservation (MDC) and the Missouri Conservation Commission were created by Article IV Sections 40-42 of the Missouri Constitution, which were adopted by the voters of the state in 1936 as Amendment 4 to the constitution ...

says:

The name 'hellbender' probably comes from the animal's odd look. One theory claims the hellbender was named by settlers who thought "it was a creature from hell where it's bent on returning." Another rendition says the undulating skin of a hellbender reminded observers of "horrible tortures of the infernal regions." In reality, it's a harmless aquatic salamander.

Other vernacular names include snot otter, lasagna lizard, devil dog, mud-devil, mud dog, water dog, grampus,Dictionary of American Regional English: "grampus"
/ref> Allegheny alligator, and leverian water newt. The generic name, ''Cryptobranchus'', is derived from the Ancient Greek (hidden) and (gill). The

subspecific name In zoological nomenclature, a subspecific name is the third part of a trinomen. In zoology there is only one rank below that of species, namely "subspecies". In botanical nomenclature, there are several levels of subspecific names, such as ''vari ...

''bishopi'' is in honor of American herpetologist Sherman C. Bishop.

Description

''C. alleganiensis'' has a flat body and head, with beady dorsal

eye Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and con ...

s and slimy skin. Like most salamanders, it has short legs with four toes on the front legs and five on its back limbs, and its tail is keeled for propulsion. Their tail is shaped like a rudder, but it is rarely used for swimming; these salamanders use pads on their toes instead to grip rocks and walk up and down streams instead of swimming.Humphries, Jeffrey W; & Pauley, Thomas K. (2005). Life History of the Hellbender, Cryptobranchus alleganiensis, in a West Virginia Stream. The American Midland Naturalist, 154(1), 135–142. https://doi.org/10.1674/0003-0031(2005)154 135:LHOTHC.0.CO;2 The hellbender has working lungs, but gill slits are often retained, although only immature specimens have true gills; the hellbender absorbs oxygen from the water through capillaries of its side frills. Only occasionally leaving the water, the hellbender makes little use of these lungs and the juveniles lose their external lungs after around 18 months Hellbenders use their lungs for buoyancy more than breathing. It is blotchy brown or red-brown in color, with a paler underbelly. Both males and females grow to an adult length of from snout to

vent Vent or vents may refer to: Science and technology Biology *Vent, the cloaca region of an animal * Vent DNA polymerase, a thermostable DNA polymerase Geology *Hydrothermal vent, a fissure in a planet's surface from which geothermally heated wate ...

, with a total length of , making them the fourth-largest aquatic salamander species in the world (after the

South China giant salamander The South China giant salamander (''Andrias sligoi'') may be the largest species of salamander and the largest amphibian in the world. It is endemic to southern China, mainly in the Pearl River basin south of the Nanling Mountains. It is extreme ...

, the

Chinese giant salamander The Chinese giant salamander (''Andrias davidianus'') is one of the largest salamanders and one of the largest amphibians in the world.Japanese giant salamander The Japanese giant salamander (''Andrias japonicus'') is a species of fully aquatic giant salamander endemic to Japan. With a length of up to ,reticulated siren of the southeastern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ...

(although the siren is much leaner in build). An adult weighs , making them the fifth heaviest living amphibian in the world after their South China, Chinese and Japanese cousins and the

goliath frog The goliath frog (''Conraua goliath''), otherwise known commonly as the giant slippery frog and the goliath bullfrog, is a species of frog in the family Conrauidae. The goliath frog is the largest living frog. Specimens can grow up to in lengt ...

, while the largest

cane toad The cane toad (''Rhinella marina''), also known as the giant neotropical toad or marine toad, is a large, terrestrial true toad native to South and mainland Central America, but which has been introduced to various islands throughout Oceania ...

s may also weigh as much as a hellbender. Hellbenders reach sexual maturity at about five years of age, and may live 30 years in captivity.Mayasich, J.; Grandmaison, D.; Phillips, C. (June 2003
Eastern Hellbender Status Assessment Report
/ref> The hellbender has a few characteristics that make it distinguishable from other native salamanders, including a gigantic, dorsoventrally flattened body with thick folds travelling down the sides, a single open

gill slit Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of cartilaginous fish such as sharks and rays, as well as deep-branching vertebrates such as lampreys. In co ...

on each side, and hind feet with five toes each. Easily distinguished from most other endemic salamander species simply by their size, hellbenders average up to 60 cm or about 2 ft in length; the only species requiring further distinction (due to an overlap in distribution and size range) is the

common mudpuppy The common mudpuppy (''Necturus maculosus'') is a species of salamander in the genus '' Necturus''. They live an entirely aquatic lifestyle in parts of North America in lakes, rivers, and ponds. They go through paedomorphosis and retain their e ...

(''Necturus maculosus'').''Cryptobranchus alleganiensis''
AmphibiaWeb: Information on amphibian biology and conservation. eb application 2012. Berkeley, California: AmphibiaWeb. Available: http://amphibiaweb.org/. (Accessed: 15 November 2012). This demarcation can be made by noting the presence of external gills in the mudpuppy, which are lacking in the hellbender, as well as the presence of four toes on each hind foot of the mudpuppy (in contrast with the hellbender's five). Furthermore, the average size of ''C. a. alleganiensis'' has been reported to be 45–60 cm (with some reported as reaching up to 74 cm or 30 in), while ''N. m. maculosus'' has a reported average size of in length, which means that hellbender adults will still generally be notably larger than even the biggest mudpuppies.

Taxonomy

The genus ''Cryptobranchus'' has historically only been considered to contain one species, ''C. alleganiensis'', with two subspecies, ''C. a. alleganiensis'' and ''C. a. bishopi''. A recent decline in population size of the Ozark subspecies ''C. a. bishopi'' has led to further research into populations of this subspecies, including genetic analysis to determine the best method for conservation. Crowhurst et al., for instance, found that the "Ozark subspecies" denomination is insufficient for describing genetic (and therefore evolutionary) divergence within the genus ''Cryptobranchus'' in the Ozark region. They found three equally divergent genetic units within the genus: ''C. a. alleganiensis'', and two distinct eastern and western populations of ''C. a. bishopi''. These three groups were shown to be isolated, and are considered to most likely be "diverging on different evolutionary paths".

Distribution

Hellbenders are present in a number of Eastern US states, from southern

New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * ...

to northern

Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...

, including parts of

Ohio Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...

Pennsylvania Pennsylvania (; (Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, Mary ...

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to it ...

West Virginia West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the ...

Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth are ...

Kentucky Kentucky ( , ), officially the Commonwealth of Kentucky, is a U.S. state, state in the Southeastern United States, Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to ...

Illinois Illinois ( ) is a state in the Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolitan areas include, Peoria and Rockfo ...

Indiana Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th st ...

Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to t ...

North Carolina North Carolina () is a state in the Southeastern region of the United States. The state is the 28th largest and 9th-most populous of the United States. It is bordered by Virginia to the north, the Atlantic Ocean to the east, Georgia and S ...

South Carolina )'' Animis opibusque parati'' ( for, , Latin, Prepared in mind and resources, links=no) , anthem = " Carolina";" South Carolina On My Mind" , Former = Province of South Carolina , seat = Columbia , LargestCity = Charleston , LargestMetro = ...

Alabama (We dare defend our rights) , anthem = " Alabama" , image_map = Alabama in United States.svg , seat = Montgomery , LargestCity = Huntsville , LargestCounty = Baldwin County , LargestMetro = Greater Birmingham , area_total_km2 = 135,7 ...

Mississippi Mississippi () is a state in the Southeastern region of the United States, bordered to the north by Tennessee; to the east by Alabama; to the south by the Gulf of Mexico; to the southwest by Louisiana; and to the northwest by Arkansas. Missis ...

Arkansas Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage la ...

Missouri Missouri is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it is bordered by eight states (tied for the most with Tennessee ...

, and extending into

Oklahoma Oklahoma (; Choctaw: ; chr, ᎣᎧᎳᎰᎹ, ''Okalahoma'' ) is a state in the South Central region of the United States, bordered by Texas on the south and west, Kansas on the north, Missouri on the northeast, Arkansas on the east, New M ...

and

Kansas Kansas () is a state in the Midwestern United States. Its capital is Topeka, and its largest city is Wichita. Kansas is a landlocked state bordered by Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the w ...

. The subspecies (or species, depending on the source) ''C. a. bishopi'' is confined to the

Ozarks The Ozarks, also known as the Ozark Mountains, Ozark Highlands or Ozark Plateau, is a physiographic region in the U.S. states of Missouri, Arkansas, Oklahoma and the extreme southeastern corner of Kansas. The Ozarks cover a significant porti ...

of northern Arkansas and southern Missouri, while ''C. a. alleganiensis'' is found in the rest of these states. Some hellbender populations—namely a few in Missouri, Pennsylvania, and Tennessee—have historically been noted to be quite abundant, but several man-made threats have converged on the species such that it has seen a serious population decline throughout its range. Hellbender populations were listed in 1981 as already extinct or endangered in Illinois, Indiana, Iowa, and Maryland, decreasing in Arkansas and Kentucky, and generally threatened as a species throughout their range by various human activities and developments.

Ecology

The hellbender salamander, considered a "habitat specialist", has adapted to fill a specific niche within a very specific environment, and is labeled as such "because its success is dependent on a constancy of dissolved oxygen, temperature and flow found in swift water areas", which in turn limits it to a narrow spectrum of stream/river choices. As a result of this specialization, hellbenders are generally found in areas with large, irregularly shaped, and intermittent rocks and swiftly moving water, while they tend to avoid wider, slow-moving waters with muddy banks and/or slab rock bottoms. This specialization likely contributed to the decline in their populations, as collectors could easily identify their specific habitats. One collector noted, at one time, "one could find a specimen under almost every suitable rock", but after years of collecting, the population had declined significantly. The same collector noted, he "never found two specimens under the same rock", corroborating the account given by other researchers that hellbenders are generally solitary; they are thought to gather only during the mating season. Both subspecies, ''C. a. alleganiensis'' and ''C. a. bishopi'' undergo a

metamorphosis Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insec ...

after around a year and a half of life. At this point, when they are roughly long, they lose the gills present during their larval stage. Until then, they are easily confused with mudpuppies, and can be differentiated often only through toe number. After this metamorphosis, hellbenders must be able to absorb oxygen through the folds in their skin, which is largely behind the need for fast-moving, oxygenated water. If a hellbender ends up in an area of slow-moving water, not enough of it will pass over its skin in a given time, making it difficult to garner enough oxygen to support necessary respiratory functions. A below-favorable oxygen content can make life equally difficult. Hellbenders are preyed upon by diverse predators, including various fish and reptiles (including both snakes and turtles).

Cannibalism Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is well documented, bo ...

of eggs is also considered a common occurrence.

Life history and behavior

Behavior

Once a hellbender finds a favorable location, it generally does not stray too far from it—except occasionally for breeding and hunting—and will protect it from other hellbenders both in and out of the breeding season. While the range of two hellbenders may overlap, they are noted as rarely being present in the overlapping area when the other salamander is in the area. The species is at least somewhat nocturnal, with peak activity being reported by one source as occurring around "two hours after dark" and again at dawn (although the dawn peak was recorded in the lab and could be misleading as a result). Nocturnal activity has been found to be most prevalent in early summer, perhaps coinciding with highest water depths.

Diet

''C. alleganiensis'' feeds primarily on

crayfish Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, mu ...

and small fish, but also

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of ...

tadpole A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found in ...

s and smaller salamanders. One report, written by a commercial collector in the 1940s, noted a trend of more crayfish predation in the summer during times of higher prey activity, whereas fish made up a larger part of the winter diet, when crayfish are less active. There seems to be a specific temperature range in which hellbenders feed, as well: between . Cannibalism—mainly on eggs—has been known to occur within hellbender populations. One researcher claimed perhaps density is maintained, and density dependence in turn created, in part by intraspecific predation.

Reproduction

The hellbenders'

breeding season Seasonal breeders are animal species that successfully mate only during certain times of the year. These times of year allow for the optimization of survival of young due to factors such as ambient temperature, food and water availability, and cha ...

begins in late August or early- to mid-September and can continue as late as the end of November, depending on region. They exhibit no

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most anim ...

, except during the fall mating season, when males have a bulging ring around their

cloaca In animal anatomy, a cloaca ( ), plural cloacae ( or ), is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles and birds, an ...

l glands. Unlike most salamanders, the hellbender performs

external fertilization External fertilization is a mode of reproduction in which a male organism's sperm fertilizes a female organism's egg outside of the female's body. It is contrasted with internal fertilization, in which sperm are introduced via insemination and then ...

. Before mating, each male excavates a brood site, a saucer-shaped depression under a rock or log, with its entrance positioned out of the direct current, usually pointing downstream. The male remains in the brood site awaiting a female. When a female approaches, the male guides or drives her into his burrow and prevents her from leaving until she oviposits. Female hellbenders lay 150–200 eggs over a two- to three-day period; the eggs are in diameter, connected by five to ten cords. As the female lays eggs, the male positions himself alongside or slightly above them, spraying the eggs with sperm while swaying his tail and moving his hind limbs, which disperses the sperm uniformly. The male often tempts other females to lay eggs in his nest, and as many as 1,946 eggs have been counted in a single nest. Males also exhibit mate and shelter guarding. Studies have found that until the female successfully reproduces, the male hellbender will guard her in his territory until the reproduction is complete.

, however, leads to a much lower number of eggs in hellbender nests than would be predicted by egg counts. After oviposition, the male drives the female away from the nest and guards the eggs. Incubating males rock back and forth and undulate their lateral skin folds, which circulates the water, increasing oxygen supply to both eggs and adult. Incubation lasts from 45 to 75 days, depending on region. Hatchling hellbenders are long, have a

yolk sac The yolk sac is a membranous sac attached to an embryo, formed by cells of the hypoblast layer of the bilaminar embryonic disc. This is alternatively called the umbilical vesicle by the Terminologia Embryologica (TE), though ''yolk sac'' is fa ...

as a source of energy for the first few months of life, and lack functional limbs.

Adaptations

Hellbenders are superbly adapted to the shallow, fast-flowing, rocky streams in which they live. Their flattened shape offers little resistance to the flowing water, allowing them to work their way upstream and also to crawl into narrow spaces under rocks. Although their eyesight is relatively poor, they have light-sensitive cells all over their bodies. Those on their tails are especially finely tuned and may help them position safely under rocks without their tails poking out to give themselves away. They have a good sense of smell and move upstream in search of food such as dead fish, following the trail of scent molecules. Smell is possibly their most important sense when hunting. They also have a

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

similar to those of fish, with which they can detect vibrations in the water. Hellbender Salamander

Conservation status

Research throughout the range of the hellbender has shown a dramatic decline in populations in the majority of locations. As of 2022, the species is classified as Vulnerable by the IUCN. Many different

anthropogenic Anthropogenic ("human" + "generating") is an adjective that may refer to: * Anthropogeny, the study of the origins of humanity Counterintuitively, anthropogenic may also refer to things that have been generated by humans, as follows: * Human im ...

sources have helped to create this decline, including the

siltation Siltation, is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary or ...

and sedimentation, blocking of dispersal/migration routes, and destruction of riverine habitats created by dams and other development, as well as pollution, disease and overharvesting for commercial and scientific purposes. As many of these detrimental effects have irreversibly damaged hellbender populations, it is important to conserve the remaining populations through protecting habitats and—perhaps in places where the species was once endemic and has been extirpated—by augmenting numbers through

reintroduction Species reintroduction is the deliberate release of a species into the wild, from captivity or other areas where the organism is capable of survival. The goal of species reintroduction is to establish a healthy, genetically diverse, self-sustainin ...

. Due to sharp decreases seen in the Ozark subspecies, researchers have been trying to differentiate ''C. a. alleganiensis'' and ''C. a. bishopi'' into two management units. Indeed, researchers found significant genetic divergence between the two groups, as well as between them and another isolated population of ''C. a. alleganiensis''. This could be reason enough to ensure work is done on both subspecies, as preserving extant

genetic diversity Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species, it ranges widely from the number of species to differences within species and can be attributed to the span of survival for a species. It is dis ...

is of crucial ecological importance. The Ozark hellbender has been listed as an endangered species under the

Endangered Species Act The Endangered Species Act of 1973 (ESA or "The Act"; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of ec ...

by the

US Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with oth ...

since October 5, 2011. This hellbender subspecies inhabits the White River and Spring River systems in southern Missouri and northern Arkansas, and its population has declined an estimated 75% since the 1980s, with only about 590 individuals remaining in the wild. Degraded water quality, habitat loss resulting from impoundments, ore and gravel mining, sedimentation, and collection for the

pet trade Wildlife trade refers to the of products that are derived from non-domesticated animals or plants usually extracted from their natural environment or raised under controlled conditions. It can involve the trade of living or dead individuals, ti ...

are thought to be the main factors resulting in the amphibian's decline. When

chytridiomycosis Chytridiomycosis ( ) is an infectious disease in amphibians, caused by the chytrid fungi ''Batrachochytrium dendrobatidis'' and ''Batrachochytrium salamandrivorans''. Chytridiomycosis has been linked to dramatic population declines or extinct ...

killed 75% of the St. Louis Zoo's captive hellbender population between March 2006 and April 2007, tests began to be conducted on wild populations. The disease has been detected in all Missouri populations of the Ozark hellbender.

NatureServe NatureServe, Inc. is a non-profit organization based in Arlington County, Virginia, US, that provides proprietary wildlife conservation-related data, tools, and services to private and government clients, partner organizations, and the public. Nat ...

treats ''C. a. alleganiensis'' as an ''Imperiled Subspecies'', ''C. a. bishopi'' as a ''Critically Imperiled Subspecies'', and the species as a whole as ''Vulnerable''. The Ozark hellbender was successfully bred in captivity for the first time at the

St. Louis Zoo The Saint Louis Zoo, officially known as the Saint Louis Zoological Park, is a zoo in Forest Park, St. Louis, Missouri. It is recognized as a leading zoo in animal management, research, conservation, and education. The zoo is accredited by the ...

, in a joint project with the Missouri Department of Conservation, hatching on November 15, 2011. Apart from the Ozark efforts, head-starting programs, in which eggs are collected from the wild and raised in captivity for re-release at a less vulnerable stage, have been initiated in New York and Ohio. Members of the

Pennsylvania State Senate The Pennsylvania State Senate is the upper house of the Pennsylvania General Assembly, the Pennsylvania state legislature. The State Senate meets in the State Capitol building in Harrisburg. Senators are elected for four year terms, staggered ev ...

have voted to approve the eastern hellbender as the official

state amphibian This is a list of official U.S. state, federal district, and territory amphibians. State amphibians are designated by tradition or the respective state legislatures.

in an effort to raise awareness about its endangered status. The legislation has been mired in controversy due to a dispute by House members who argue that Wehrle's salamander should be given the honor. The legislation did not pass in 2018, but was reintroduced in 2019. On April 23, 2019, Pennsylvania Governor

Tom Wolf Thomas Westerman Wolf (born November 17, 1948) is an American politician and businessman serving as the 47th governor of Pennsylvania since 2015. A member of the Democratic Party, he defeated Republican incumbent Tom Corbett in the 2014 gu ...

signed legislation making the eastern hellbender Pennsylvania's official state amphibian. Youth members of the

Chesapeake Bay Foundation The Chesapeake Bay Foundation (CBF) is a non-profit organization devoted to the restoration and protection of the Chesapeake Bay in the United States. It was founded in 1967 and has headquarters offices in Annapolis, Maryland. The foundation has ...

's Pennsylvania Student Leadership Council were heavily involved writing and advocating on behalf of this legislation. They hope that the success of the hellbender bill in the Pennsylvania Senate will contribute to clean water efforts and raise awareness for the hellbender's struggling population.

References

External links

Hellbender ''Cryptobranchus alleganiensis'' field guide
from the Missouri Department of Conservation
Eastern hellbender information
at Commonwealth of Virginia.

at New York State.
''Cryptobranchus ''
at CalPhotos. {{Taxonbar, from=Q369467 Amphibians of the United States Endemic fauna of the United States Amphibians described in 1803 Cryptobranchidae Extant Gelasian first appearances Natural history of the Great Smoky Mountains Taxa named by François Marie Daudin Symbols of Pennsylvania