Ozark hellbender

Last updated

Contents

Ozark hellbender
Ozark hellbender.jpg
Status TNC T1.svg
Critically Imperiled  (NatureServe) [1]
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Urodela
Family: Cryptobranchidae
Genus: Cryptobranchus
Species:
C. alleganiensis
Subspecies:
C. a. bishopi
Trinomial name
Cryptobranchus alleganiensis bishopi
Grobman, 1943
Cryptobranchus alleganiensis bishopi range map.png
Distribution map of the Ozark hellbender

The Ozark hellbender (Cryptobranchus alleganiensis bishopi) is a subspecies of the hellbender (Cryptobranchus alleganiensis). The subspecies is strictly native to the mountain streams of the Ozark Plateau in southern Missouri and northern Arkansas. [4] Its nicknames include lasagna lizard and snot otter. [5] This large salamander grows to a total length (including tail) of 29–57 cm (11–22 in) over a lifespan of 30 years. [6] The Ozark hellbender is a nocturnal predator that hides under large flat rocks and primarily consumes crayfish and small fish. As of 2011, the U.S. Fish and Wildlife Service (USFWS) has listed the subspecies as endangered under the Endangered Species Act of 1973. [3] The population decline of the subspecies is caused by habitat destruction and modification, overutilization, disease and predation, and low reproductive rates. [7] Conservation programs have been put in place to help protect the subspecies. [8] [7]

Taxonomy

Two distinct members of the family Cryptobranchidae, also known as "giant salamanders," are found in the United States, the eastern hellbender (Cryptobranchus a. alleganiensis), and the Ozark hellbender (Cryptobranchus a. bishopi). [9]

Description

The Ozark hellbender is known for its primitive body design and its large size. It has small eyes, a keeled tail, and a flat body to assist in movement in rivers and streams. [10] It has folds along its sides that assist in respiration, as oxygen is able to diffuse across the skin. [6] It is a strictly aquatic subspecies, even though it technically lacks gills. [11] It grows to a total length (including tail) of about 29–57 cm (11–22 in). [6]

Distribution and habitat

The Ozark hellbender is endemic to the White River drainage in northern Arkansas and southern Missouri. Historically it has been found in portions of the Spring, White, Black, Eleven Point, and Current rivers and their tributaries. The Ozark hellbender is now considered extirpated in the mainstem White, Black, and Spring rivers and Jacks Fork, and with its range being considerably reduced in the remaining rivers and tributaries. [12]

The Ozark hellbender is declining throughout its range with no population appearing to be stable throughout its range. [13] It is unknown whether a viable population exists in the mainstem of the White River, where few individuals have been found. Much of the potential habitat along this river has been destroyed by a series of dams constructed on the upper portion of the river in the 1940s and 1950s. [14] The North Fork White River has historically contained a high population of the Ozark hellbender and was considered the strong point for the subspecies, with a mark and recapture study in 1973 marking 1,150 individuals within a 1.7-mile (2.7-kilometer) reach of the river. [15] In recent years, this population is now beginning to experience a decline similar to those populations in other rivers. [14] Though the overall population of the Ozark hellbender is known to be in decline, there is no data available on current population sizes, likely due to its small numbers and reclusive life history. [16]

There is currently no critical habitat designated for the Ozark hellbender. [3]

The Ozark hellbender is frequently found underneath large flat rocks in rocky, fast flowing streams in the Ozark Plateau at depths from less than 1 m (3.3 ft) to 3 m (9.8 ft). [10] It is primarily nocturnal, remaining undercover until nightfall. Hellbenders are habitat specialists that are dependent on consistent levels of dissolved oxygen, temperature, and water flow. [17] Warmer stagnant waters with a low dissolved oxygen content do not meet the Ozark hellbender's respiratory needs. [17] It has been observed that Ozark hellbenders in warm stagnant waters sway or rock in order to increase oxygen exposure. [17]

Ecology and behavior

Ozark hellbenders are nocturnal predators, remaining beneath rock cover during the day and emerging to forage at night, primarily on crayfish. [18] They become diurnal during the breeding season, searching for mates. [6] They are highly sedentary, moving very little throughout their entire lifespan. [18] Ozark hellbenders are territorial and will defend their cover from other hellbenders.

They have been recorded living 25 to 30 years in the wild and grow slowly over time. [19] Wild Ozark hellbender populations are dominated by these older and larger individuals. Female Ozark hellbenders have been found to mature at 6 to 8 years old, while males tend to mature at around 5 years of age. [4] [19] [20] Some of the issues that Ozark hellbenders have in reproduction come from their late sexual maturity. [7]

Typically, Ozark hellbenders breed in mid-October, although certain populations that live in the Spring River area tend to procreate in the winter. Paternal care is present in this subspecies, even though it is rare to see this in tetrapods. [21] The males are responsible for preparing the nests and ultimately guarding the eggs. They build nests under submerged logs, flat rocks, or within bedrocks. Hellbenders mate via external fertilization. [4] Usually, around 138 to 450 eggs are present per nest, [6] and they hatch after approximately 80 days. [22] Once the eggs hatch, the larvae and juveniles hide under small and large rocks in gravel beds. [4] [23] Ozark hellbenders are highly sedentary creatures, meaning that neither males nor females have long distance dispersal rates. [10]

Conservation status

The Endangered Species Act of 1973

The Ozark hellbender became a candidate for listing under the Endangered Species Act in 2001. It was assigned a priority level of 6 for threats due to habitat loss and fragmentation because of human activity and pollution. [24] In 2005 the Fish and Wildlife Service increased its listing priority number to a 3 because of increased pressures on the species from recreation activity in their habitat including gigging and boat traffic, and increases in the contamination of their waters. [25] The USFWS put forth the proposed rule to list the Ozark hellbender as endangered under the ESA in September 2010, and the listing of the species as endangered became effective November 7, 2011. [3] [26] In April 2017, a five-year review of the subspecies’ status was initiated. [27]

IUCN

The subspecies of C. a. bishopi does not currently have its own IUCN listing, but the species C. alleganiensis was listed as near threatened in April 2004. [16]

Threats

Human impact

The construction of reservoirs in the White River has destroyed Ozark hellbender habitats and separated their populations. [7] These reservoirs also increase predation and the deposition of silt upstream from the reservoir, both of which threaten hellbenders. [7] Siltation endangers the larval salamanders because it fills in the gravel stream beds where they live, reducing their ability to find food and hide from predators. Silt can also destroy their eggs. [7] Agricultural and construction runoff, waste disposal, and mining activity within the hellbender’s range pollute and degrade their habitat and threaten hellbender survival. [7] [25] Mining is especially detrimental as it increases zinc and leads hellbender habitats to dangerously high levels for aquatic life. [10] Human and livestock waste from the areas surrounding hellbender habitats have further decreased water quality. [25] Pollution is readily taken up by hellbenders due to the absorptive properties of their skin and decreases in water quality can make rivers and streams unlivable for this subspecies. [10] [17]

Recreation in Ozark hellbender habitats also harms populations. Boat traffic, including canoes, kayaks, and motor boats may injure or kill hellbenders and further degrade their habitat. [10] [25]

Additionally, direct removal from the environment has contributed to the decline of the Ozark hellbender. While Missouri and Arkansas have decreased or stopped issuing permits for scientific collection since the 1990s, illegal harvesting for the pet trade has continued. [7] [10] The Ozark hellbender also experiences predation from non-native rainbow and brown trout stocked in river for sport fishing. [7] [10]

Other threats

Like most amphibians globally, the Ozark hellbender is at risk of chytridiomycosis, a very infectious amphibian fungal disease. Individuals carrying the causal pathogen Batrachochytrium dendrobatidis have been detected in all surveyed C. a. bishopi populations. [3] : 61969  Additionally, unusual physical abnormalities have been observed in Ozark hellbenders in recent years, such as missing limbs or eyes and epidermal lesions, with increasing frequency, although the cause of these deformities is currently unknown. [7] [10]

The small size of Ozark hellbender populations combined with their isolation from each other puts them at greater risk of extinction, as does the documented loss of genetic diversity within those populations. [7] [10] They also suffer from very low reproductive rates as a result of their late sexual maturity and long lifespans. Their late sexual maturity makes them more likely to die before reproducing and the time between generations is extended when reproduction does occur. Very low numbers of juvenile Ozark hellbenders in most populations confirm these problems. [10] These threats are further worsened when combined with the other threats to this subspecies. [7] [10]

Fish stocking for recreational purposes increases the abundance of these potential predators of Ozark hellbenders. [3] : 61970–61971  Prey-seeking behavior of walleye and brown trout increases when these fish are exposed to Ozark hellbender alarm secretions, but it is unclear if the secretions may function to deter predation in a natural environment. [28]

Conservation efforts

The decline of the Ozark hellbender was first recognized in the 1990s. Since then, the Arkansas Game and Fish Commission (AGFC) and Missouri Department of Conservation (MDC) have begun to track the health and wellbeing of the creatures. They also study trends in their size and overall presence in their natural habitat. From this information, they are able to predict population trends. Since this species is now considered endangered, there is more effort to protect the habitat and populations of the Ozark hellbender. Both USFWS and State agencies have enacted laws and policies to aid in hellbender protection. [7]

The most popular conservation strategy for the Ozark hellbender is captive breeding and reintroduction back into their natural habitats. There is currently only one successful example of successful captive breeding, which is taking place in the Saint Louis Zoo. [8] In regards to hellbender release after captive breeding, planning should include data on genetic information and the presence of chytrid fungus and other pathogens. Since there is little gene flow or genetic variation in the subspecies, it is hard to continue to build their numbers due to negative consequences from inbreeding. Some scientists suggest research into their genetic delineations for answers. Not much is known about their genetic history. Many scientists also suggest that translocation should not be a part of Ozark hellbender conservation plans, since they are habitat specialists and haven’t had translocation success in the past. [29] Other current conservation plans include population monitoring, protecting populations and habitat, and disease assessment and treatment [7]

Due to the impact of disease on the Ozark hellbender populations, there is more effort to study the physical deformities of the hellbenders affected by disease, as well as understanding how diseases cause the deformities. Research is also exploring the effects of the amphibian chytrid fungus. Heat treatment has seen some success as a method of treating chytrid cases. [7]

Other than captive release programs, the recommended way to meet the recovery needs of Ozark hellbenders is to protect and clean their habitat. It is necessary to decrease sedimentation and to protect areas where Ozark hellbenders reproduce. [7]

Related Research Articles

<span class="mw-page-title-main">Hellbender</span> Species of amphibian

The hellbender, also known as the hellbender salamander, is a species of aquatic giant salamander endemic to the eastern and central United States. It is the largest salamander in North America. A member of the family Cryptobranchidae, the hellbender is the only extant member of the genus Cryptobranchus. Other closely related salamanders in the same family are in the genus Andrias, which contains the Japanese and Chinese giant salamanders. The hellbender, which is much larger than all other salamanders in its geographic range, employs an unusual means of respiration, and fills a particular niche—both as a predator and prey—in its ecosystem, 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 due to the impacts of disease and widespread habitat loss and degradation throughout much of its range.

<span class="mw-page-title-main">Giant salamander</span> Family of amphibians

The Cryptobranchidae are a family of fully aquatic salamanders commonly known as the giant salamanders. They include some of the largest living amphibians. The family is native to China, Japan, and the eastern United States. They constitute one of two living families—the other being the Asiatic salamanders belonging to the family Hynobiidae—within the Cryptobranchoidea, one of two main divisions of living salamanders.

<span class="mw-page-title-main">Barton Springs salamander</span> Species of amphibian

The Barton Springs salamander is an endangered lungless salamander. It is endemic to Texas, United States. It was first found in Barton Springs in Austin, but is now also known from other localities in the nearby Travis and Hays Counties. Barton Springs is located within Zilker Park which is situated in the Edwards Aquifer in Austin, Texas. Eliza Springs, located within Barton Springs, has one of the largest populations of Barton Springs salamanders.

<span class="mw-page-title-main">Meramec River</span> River in the American state of Missouri

The Meramec River, sometimes spelled Maramec River, is one of the longest free-flowing waterways in the U.S. state of Missouri, draining 3,980 square miles (10,300 km2) while wandering 218 miles (351 km) from headwaters southeast of Salem to where it empties into the Mississippi River near St. Louis at Arnold and Oakville. The Meramec watershed covers six Missouri Ozark Highland counties—Dent, Phelps, Crawford, Franklin, Jefferson, and St. Louis—and portions of eight others—Maries, Gasconade, Iron, Washington, Reynolds, St. Francois, Ste. Genevieve, and Texas. Between its source and its mouth, it falls 1,025 feet (312 m). Year-round navigability begins above Maramec Spring, just south of St. James. The Meramec's size increases at the confluence of the Dry Fork, and its navigability continues until the river enters the Mississippi at Arnold, Missouri.

<span class="mw-page-title-main">California tiger salamander</span> Species of amphibian

The California tiger salamander is a vulnerable amphibian native to California. It is a mole salamander. Previously considered to be a subspecies of the tiger salamander, the California tiger salamander was recently designated a separate species again. The California tiger salamander distinct population segment (DPS) in Sonoma County and the Santa Barbara County DPS are listed as federally endangered, while the Central California DPS is listed as federally threatened. The Sonoma County, south San Joaquin, and the Santa Barbara County DPS have diverged from the rest of the California tiger salamander populations for over one million years, since the Pleistocene and they may warrant status as separate species.

<span class="mw-page-title-main">Ozark cavefish</span> Species of fish

The Ozark cavefish, Amblyopsis rosae, is a small subterranean freshwater fish endemic to the United States. It has been listed as a threatened species in the US since 1984; the IUCN currently lists the species as Near Threatened, though it was previously listed as Vulnerable between 1986 and 1996. It is listed as Endangered and Threatened by the Missouri Department of Conservation.

<span class="mw-page-title-main">Frosted flatwoods salamander</span> Species of amphibian

The frosted flatwoods salamander is an endangered salamander species native to the Southeastern United States.

<span class="mw-page-title-main">Long-toed salamander</span> Species of amphibian

The long-toed salamander is a mole salamander in the family Ambystomatidae. This species, typically 4.1–8.9 cm (1.6–3.5 in) long when mature, is characterized by its mottled black, brown, and yellow pigmentation, and its long outer fourth toe on the hind limbs. Analysis of fossil records, genetics, and biogeography suggest A. macrodactylum and A. laterale are descended from a common ancestor that gained access to the western Cordillera with the loss of the mid-continental seaway toward the Paleocene.

<span class="mw-page-title-main">Mountain yellow-legged frog</span> Species of amphibian

The mountain yellow-legged frog, also known as the southern mountain yellow-legged frog, is a species of true frog endemic to California in the United States. It occurs in the San Jacinto Mountains, San Bernardino Mountains, and San Gabriel Mountains in Southern California and the Southern Sierra Nevada. It is a federally listed endangered species, separated into two distinct population segments (DPS): a northern DPS, listed endangered in 2014, and a southern DPS that was listed endangered in 2002.

<span class="mw-page-title-main">Wyoming toad</span> Species of amphibian

The Wyoming toad, also known commonly as Baxter's toad, is a species of toad in the family Bufonidae. The Wyoming toad is an extremely rare amphibian that exists only in captivity and within Mortenson Lake National Wildlife Refuge in Wyoming in the United States. The Wyoming toad was listed as an endangered species in 1984, and listed as extinct in the wild since 1991. As with black-footed ferrets at the Tom Thorne and Beth Williams Wildlife Research Center at Sybille in Wheatland, Wyoming, the effort to save the Wyoming toad has been a cooperative effort among state and federal agencies and private landowners. The Wyoming toad was common from the 1950s through the early 1970s, but its distribution was limited to the Laramie Basin in Albany County. The population crashed around 1975 and was extremely low by 1980. The Wyoming toad was federally listed as endangered in January 1984. To prevent extinction, a captive-breeding program began in 1989 at the Thorne Williams Unit that produced enough offspring in its first few years to supply seven zoos, and in 1998 the Saratoga National Fish Hatchery received captive-breeding stock. Nearly 46,000 offspring were produced at the Thorne Williams Unit from 1995 until 2006, when the remaining captive stock was moved to the Red Buttes Environmental Biology Laboratory south of Laramie, and then released back into the wild. Before the sharp declines occurred, this toad had been originally classified as Bufo hemiophrys baxteri, a subspecies of the Canadian toad, by Kenneth Raymond Porter in 1968.

<span class="mw-page-title-main">Crystal darter</span> Species of fish

The crystal darter is a species of freshwater ray-finned fish, a darter from the subfamily Etheostomatinae, part of the family Percidae, which also contains the perches, ruffes and pikeperches. This small North American fish is found in small, moderate, and swift rivers in the drainage basins of the Mississippi and Ohio Rivers. It is now extirpated from a majority of its range along the Ohio River.

<span class="mw-page-title-main">Red Hills salamander</span> Species of amphibian

The Red Hills salamander is a fairly large, terrestrial salamander growing to about 255 millimetres (10.0 in). Its body color is gray to brownish without markings, and its limbs are relatively short. It is the official state amphibian of Alabama, the state it is endemic to. It is the only species in the genus Phaeognathus.

<span class="mw-page-title-main">Guam kingfisher</span> Species of kingfisher from the United States Territory of Guam

The Guam kingfisher is a species of kingfisher from the United States Territory of Guam. It is restricted to a captive breeding program following its extinction in the wild due primarily to predation by the introduced brown tree snake.

<span class="mw-page-title-main">Shenandoah salamander</span> Species of amphibian

The Shenandoah salamander is a small, terrestrial salamander found exclusively in Shenandoah National Park in Virginia. The Shenandoah salamander inhabits a very small range of land on just three mountain peaks. Due to the small habitat range, interspecies competition, and climate change, the population of the Shenandoah salamander is vulnerable to extinction. Mitigating human effects on the habitat of the species will be essential in attempting to preserve and grow the population.

Lampsilis rafinesqueana, the Neosho mucket or Neosho pearly mussel, is a species of North American freshwater mussel endemic to Arkansas, Oklahoma, Illinois, Missouri and Kansas.

Genetic erosion is a process where the limited gene pool of an endangered species diminishes even more when reproductive individuals die off before reproducing with others in their endangered low population. The term is sometimes used in a narrow sense, such as when describing the loss of particular alleles or genes, as well as being used more broadly, as when referring to the loss of a phenotype or whole species.

<span class="mw-page-title-main">Endangered species</span> Species of organisms facing a very high risk of extinction

An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, and invasive species. The International Union for Conservation of Nature (IUCN) Red List lists the global conservation status of many species, and various other agencies assess the status of species within particular areas. Many nations have laws that protect conservation-reliant species which, for example, forbid hunting, restrict land development, or create protected areas. Some endangered species are the target of extensive conservation efforts such as captive breeding and habitat restoration.

The reticulated flatwoods salamander is a species of mole salamander, an amphibian in the family Ambystomatidae. The species is native to a small portion of the southeastern coastal plain of the United States in the western panhandle of Florida and extreme southwestern Georgia. The species once occurred in portions of southern Alabama but is now considered extirpated there. Its ecology and life history are nearly identical to its sister species, the frosted flatwoods salamander. A. bishopi inhabits seasonally wet pine flatwoods and pine savannas west of the Apalachicola River-Flint River system. The fire ecology of longleaf pine savannas is well-known, but there is less information on natural fire frequencies of wetland habitats in this region. Like the frosted flatwoods salamander, the reticulated flatwoods salamander breeds in ephemeral wetlands with extensive emergent vegetation, probably maintained by summer fires. Wetlands overgrown with woody shrubs are less likely to support breeding populations.

<span class="mw-page-title-main">Stanley E. Trauth</span>

Stanley E. Trauth is an American herpetologist and professor of zoology and environmental studies at Arkansas State University. He is also the curator of the herpetological collection of the Arkansas State University Museum of Zoology.

References

  1. ↑ NatureServe (5 April 2024). "Cryptobranchus alleganiensis bishopi". NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer. Arlington, Virginia: NatureServe. Retrieved 19 April 2024.
  2. ↑ "Ozark Hellbender (Cryptobranchus alleganiensis bishopi)". Environmental Conservation Online System. U.S. Fish & Wildlife Service. Retrieved 19 April 2024.
  3. 1 2 3 4 5 6 Endangered and Threatened Wildlife and Plants; Endangered Status for the Ozark Hellbender Salamander, 76 Fed. Reg. 61956 (Oct. 6, 2011) (to be codified at 50 C.F.R. pt 17).
  4. 1 2 3 4 Nickerson, M.A., and C.E. Mays. 1973. The hellbenders: North American giant salamanders. Milwaukee Public Museum Publications in Biology and Geology 1:1−106.
  5. ↑ "VIDEO: Snot Otters Get A Second Chance In Ohio". NPR.org. Retrieved 2020-04-20.
  6. 1 2 3 4 5 Dundee, H.A., and D.S. Dundee. 1965. Observations on the systematics and ecology of Cryptobranchus from the Ozark plateaus of Missouri and Arkansas. Copeia 1965:369−370.
  7. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 U.S. Fish and Wildlife Service. 2012. Recovery Outline for the Ozark Hellbender. Columbia, Missouri. 13 pp.
  8. 1 2 A., Rachel, et al. “Quantitative Behavioral Analysis of First Successful Captive Breeding of Endangered Ozark Hellbenders.” Frontiers, Frontiers, 14 Nov. 2018, www.frontiersin.org/articles/10.3389/fevo.2018.00205/full.
  9. ↑ Hayes, Thomas. "Cryptobranchid update: eastern hellbender/Ozark hellbender 'North America's Largest Salamander'." Endangered Species Update, vol. 24, no. 2, 2007, p. 42+. Accessed 1 Apr. 2020.
  10. 1 2 3 4 5 6 7 8 9 10 11 12 "Regulations.gov". www.regulations.gov. Retrieved 2020-04-20.
  11. ↑ Guimond, Robert W.; Hutchison, Victor H. (1973). "Aquatic Respiration: An Unusual Strategy in the Hellbender Cryptobranchus alleganiensis alleganiensis (Daudin)". Science, American Association for the Advancement of Science, 21 Dec. 1973.
  12. ↑ Johnson, T. R. (2000): The amphibians and reptiles of Missouri. Jefferson, MO: Missouri Department of Conservation.
  13. ↑ Wheeler, B. A., E. Prosen, A. Mathis, and R. F. Wilkinson. 2003. Population declines of a long-lived salamander: a 20+-year study of hellbenders, Cryptobranchus alleganiensis. Biological Conservation 109:151–156.
  14. 1 2 Irwin, K. 2008. Ozark hellbender long-term monitoring SWG project. Final Report. Arkansas Game and Fish Commission, Benton, Arkansas.
  15. ↑ Peterson, C. L., R. F. Wilkinson, Jr., M. S. Topping, and D. E. Metter. 1983. Age and growth of the Ozark hellbender (Cryptobranchus alleganiensis bishopi). Copeia 1983(1):225–231.
  16. 1 2 "IUCN Red List of Threatened Species: Cryptobranchus alleganiensis". IUCN Red List of Threatened Species. 2004-04-30. Retrieved 2020-04-20.
  17. 1 2 3 4 Williams, R. D., J. E. Gates, and C. H. Hocutt. 1981. An evaluation of known potential sampling techniques for hellbender, Cryptobranchus alleganiensis. Journal of Herpetology 15(1):23–27.
  18. 1 2 Dierenfeld, E. S., K. J. McGraw, K. Fritsche, J. T. Briggler, and J. Ettling. 2009. Nutrient composition of whole crayfish (Orconectes and Procambarus species) consumed by hellbender (Cryptobranchus alleganiensis). Herpetological Review 40(3):324–330.
  19. 1 2 Peterson, C.L., Ingersol, C.A., and R.F. Wilkinson. 1989. Winter breeding of Cryptobranchus alleganiensis bishopi in Arkansas. Copeia 1989:1031–1035.
  20. ↑ Taber, C.A., R.F. Wilkinson, Jr., and M.S. Topping. 1975. Age and growth of hellbenders in the Niangua River, Missouri. Copeia 1975:633−639.
  21. ↑ Bishop, et al. “A Quantitative Field Study of Paternal Care in Ozark Hellbenders, North America's Giant Salamanders.” Journal of Ethology, Springer Japan, 1 Jan. 1970, link.springer.com/article/10.1007/s10164-018-0553-0.
  22. ↑ Bishop, S.C. 1941. Salamanders of New York. New York State Museum Bulletin 324:1−365.
  23. ↑ LaClaire, L. V. 1993. Status review of Ozark hellbender (Cryptobranchus bishopi). U.S. Fish and Wildlife Service status review. Jackson, Mississippi.
  24. ↑ Endangered and Threatened Wildlife and Plants; Review of Plant and Animal Species That Are Candidates or Proposed for Listing as Endangered or Threatened, Annual Notice of Findings on Recycled Petitions, and Annual Description of Progress on Listing Actions, 66 Fed. Reg. 54811 (Oct. 30, 2001).
  25. 1 2 3 4 Endangered and Threatened Wildlife and Plants; Review of Native Species That Are Candidates or Proposed for Listing as Endangered or Threatened; Annual Notice of Findings on Resubmitted Petitions; Annual Description of Progress on Listing Actions, 70 Fed. Reg. 24877 (May 11, 2005).
  26. ↑ Endangered and Threatened Wildlife and Plants; Proposed Rule To List the Ozark Hellbender Salamander as Endangered, 75 Fed. Reg. 54561 (Sep. 8, 2010).
  27. ↑ Endangered and Threatened Wildlife and Plants; Initiation of 5-Year Status Reviews of Eight Endangered Animal Species, 82 Fed. Reg. 18156 (Apr. 17, 2017).
  28. ↑ Gall, Brian G.; Mathis, Alicia (2010). "Response of native and introduced fishes to presumed antipredator secretions of Ozark hellbenders (Cryptobranchus alleganiensis bishopi)". Behaviour. 147 (13–14): 1769–1789. JSTOR   25799785.
  29. ↑ Arntzen, et al. “Genetic Relationships of Hellbenders in the Ozark Highlands of Missouri and Conservation Implications for the Ozark Subspecies (Cryptobranchus Alleganiensis Bishopi).” Conservation Genetics, Springer Netherlands, 1 Jan. 1999.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.