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Overview

Comprehensive Description

Description

Calyptocephallela gayi, the Helmeted Water Toad, is a large frog, with adult males growing to 120 mm and the females to 320 mm. This frog has a robust body and a large head with a short round snout. The eyes are small, with vertical pupils and bronze irises. A distinct tympanum is visible. The skin has elongated bumps on the dorsum. Fingers are unwebbed while toes are half-webbed. These frogs are dull brown, with grayish-white bellies. During breeding season, males have nuptial pads on their thumbs (Duellman 2003).

C. gayi tadpoles grow very large, to a maximum of 150 mm in length and more than 30 g in weight (Castaneda et al. 2006). The body and foremost part of the tail are grayish brown in color (Duellman, 2003) or light green (Diaz and Valencia 1985), while the posterior part of the tail is black or dark brown (Duellman 2003). Labial papillae are present and the mandibles are well-developed, with a tooth formula of 2/3 (Diaz and Valencia 1985). The spiracle is equidistant between the snout and the vent (Diaz and Valencia 1985). The dorsal fin extends over the tail base, with the tail base narrower than half of the maximum body width (Diaz and Valencia 1985). The oral disc is small (narrower than a third of the body width), and there is no anal tube (Diaz and Valencia 1985).

This species was formerly named Caudiverbera caudiverbera but renamed by Myers and Stothers (2006) on finding that the original name was based on a mythical species.

Defenders of Wildlife and SSN have recently recommended that the United States advocate for inclusion of the helmeted water toad (Calyptocephallela gayi, formerly known as Caudiverbera caudiverbera) in Appendix II of CITES (Convention on International Trade in Endangered Species), which would recommend controls on commercial trade in this species. This species is found in Chile and may possibly occur in Argentina, in deep ponds and reservoirs. Threats include harvesting for local consumption, water pollution, and consumption by introduced trout, and pond drainage. Recent trade data for 2005 to 2008 do not specifically indicate the importation of the species into the United States. It is listed as vulnerable by IUCN with a declining population trend. There is no indication that trade is impacting the wild population.

However, the U. S. Fish and Wildlife Service reports that the U. S. is not planning to propose inclusion of Calyptocephallela gayi (formerly known as Caudiverbera caudiverbera) under CITES Appendix II unless "significant additional information is received" about the population and trade status, or assistance is requested by Chile (or Argentina). The deadline for submitting comments and information to USF&W is September 11, 2009. Species submitted for consideration by the United States and other CITES member countries will be discussed at the CoP15 meeting in Qatar on March 13-25, 2010.

Comments pertaining to species proposals should be sent to the Division of Scientific Authority, U.S. Fish and Wildlife Service, 4401 North Fairfax Drive, Room 110, Arlington, VA 22203, or via e-mail at: scientificauthority@fws.gov, or via fax at: 703-358-2276. Comments pertaining to proposed resolutions, decisions, and agenda items should be sent to the Division of Management Authority, U.S. Fish and Wildlife Service, 4401 North Fairfax Drive, Room 212, Arlington, VA 22203, or via e-mail at: CoP15@fws.gov, or via fax at: 703-358-2298.

For further information pertaining to species proposals contact: Rosemarie Gnam, Chief, Division of Scientific Authority, phone 703�358� 1708, fax 703-358-2276, e-mail: scientificauthority@fws.gov. For further information pertaining to resolutions, decisions, and agenda items contact: Robert R. Gabel, Chief, Division of Management Authority, phone 703-358-2095, fax 703-358-2298, e-mail: CoP15@fws.gov.

  • Castañeda, L.E., Sabat, P., Gonzalez, S.P., and Nespolo, R.F. (2006). ''Digestive plasticity in tadpoles of the Chilean Giant Frog (Caudiverbera caudiverbera).'' Physiological and Biochemical Zoology, 79, 919-926.
  • Duellman, W. E. (2003). ''Helmeted water toad, Caudiverbera caudiverbera.'' Grzimek's Animal Life Encyclopedia, Volume 6, Amphibians. 2nd edition. M. Hutchins, W. E. Duellman, and N. Schlager, eds., Gale Group, Farmington Hills, Michigan.
  • Dunn, E. R. (1931). ''New frogs from Panama and Costa Rica.'' Occasional Papers of the Boston Society of Natural History, 5, 385-401.
  • Stuart, S., Hoffmann, M., Chanson, J., Cox, N., Berridge, R., Ramani, P., and Young, B. (eds) (2008). Threatened Amphibians of the World. Lynx Edicions, IUCN, and Conservation International, Barcelona, Spain; Gland, Switzerland; and Arlington, Virginia, USA.
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Distribution

Range Description

This species occurs from Coquimbo (at approx. 29°S) to Puerto Montt (40°S), in Chile. It has an altitudinal range of 0-500m asl.
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Distribution and Habitat

Helmeted Water Toads are found in the lowlands of Chile, up to 500 m in elevation (Stuart 2008). They inhabit aquatic environments, such as lakes, rivers and ponds (Duellman 2003). The tadpoles prefer large bodies of lentic water (Diaz and Valencia 1985).

  • Castañeda, L.E., Sabat, P., Gonzalez, S.P., and Nespolo, R.F. (2006). ''Digestive plasticity in tadpoles of the Chilean Giant Frog (Caudiverbera caudiverbera).'' Physiological and Biochemical Zoology, 79, 919-926.
  • Duellman, W. E. (2003). ''Helmeted water toad, Caudiverbera caudiverbera.'' Grzimek's Animal Life Encyclopedia, Volume 6, Amphibians. 2nd edition. M. Hutchins, W. E. Duellman, and N. Schlager, eds., Gale Group, Farmington Hills, Michigan.
  • Dunn, E. R. (1931). ''New frogs from Panama and Costa Rica.'' Occasional Papers of the Boston Society of Natural History, 5, 385-401.
  • Stuart, S., Hoffmann, M., Chanson, J., Cox, N., Berridge, R., Ramani, P., and Young, B. (eds) (2008). Threatened Amphibians of the World. Lynx Edicions, IUCN, and Conservation International, Barcelona, Spain; Gland, Switzerland; and Arlington, Virginia, USA.
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Ecology

Habitat

Habitat and Ecology

Habitat and Ecology
It occurs in large, deep ponds, and small reservoirs, and breeding takes place in ponds. It tolerates some minor disturbance of its habitat, but requires permanent ponds to persist.

Systems
  • Terrestrial
  • Freshwater
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Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
VU
Vulnerable

Red List Criteria
A2ad

Version
3.1

Year Assessed
2010

Assessor/s
Alberto Veloso, Ramón Formas, Helen Gerson

Reviewer/s
Global Amphibian Assessment Coordinating Team (Simon Stuart, Janice Chanson, Neil Cox and Bruce Young)

Contributor/s

Justification
Listed as Vulnerable because of a population decline, estimated to be more than 30% over the last ten years, inferred from direct observation and over-exploitation.

History
  • 2004
    Vulnerable
  • 1996
    Data Deficient
  • 1994
    Vulnerable
    (Groombridge 1994)
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Population

Population
Populations of this species are currently declining in central Chile; it is practically absent in ponds and lagoons close to towns where it was very abundant only a few years ago. However, populations are apparently common and stable in southern Chile.

Population Trend
Decreasing
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Life History, Abundance, Activity, and Special Behaviors

Calyptocephallela gayi can be active at any time of day. When threatened, this frog becomes aggressive. It will inflate and elevate its body, open its mouth, lunge, and bite potential predators (Duellman 2003).

During the mating season from September through October, males give off a loud "oouu". Amplexus is axillary. After mating, females lay clutches of eggs in shallow water. The clutches consist of one to ten thousand eggs laid in clumps. Hatching occurs in about three weeks (Duellman 2003). The larvae are found in bodies of slow-moving water with muddy bottoms and plentiful vegetation, at depths of at least 1 m (Diaz and Valencia 1985). Calyptocephallela gayi larvae are large, slow swimmers (Diaz and Valencia 1985). It takes up to two years before they metamorphose into froglets (Diaz and Valencia 1985), with the typical larval period extending from 5-12 months (Castaneda et al 2006) . The froglets measure at least 2.2 cm (Diaz and Valencia 1985).

The adult diet consists of aquatic insect larvae, fishes, frogs, and small birds and mammals (Duellman 2003).

  • Castañeda, L.E., Sabat, P., Gonzalez, S.P., and Nespolo, R.F. (2006). ''Digestive plasticity in tadpoles of the Chilean Giant Frog (Caudiverbera caudiverbera).'' Physiological and Biochemical Zoology, 79, 919-926.
  • Duellman, W. E. (2003). ''Helmeted water toad, Caudiverbera caudiverbera.'' Grzimek's Animal Life Encyclopedia, Volume 6, Amphibians. 2nd edition. M. Hutchins, W. E. Duellman, and N. Schlager, eds., Gale Group, Farmington Hills, Michigan.
  • Dunn, E. R. (1931). ''New frogs from Panama and Costa Rica.'' Occasional Papers of the Boston Society of Natural History, 5, 385-401.
  • Stuart, S., Hoffmann, M., Chanson, J., Cox, N., Berridge, R., Ramani, P., and Young, B. (eds) (2008). Threatened Amphibians of the World. Lynx Edicions, IUCN, and Conservation International, Barcelona, Spain; Gland, Switzerland; and Arlington, Virginia, USA.
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Threats

Major Threats
The main threats include harvesting as an exotic food source, and water pollution due to agriculture. Introduced trout and the drainage of ponds for development and agriculture are additional threats. Two wild-caught individuals from Chile were imported into Canada via the United States in 2005 for the pet trade (H. Gerson, pers. comm. 2008).
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Life History, Abundance, Activity, and Special Behaviors

Their populations have declined due to hunting as well as loss of habitat (Duellman 2003).

  • Castañeda, L.E., Sabat, P., Gonzalez, S.P., and Nespolo, R.F. (2006). ''Digestive plasticity in tadpoles of the Chilean Giant Frog (Caudiverbera caudiverbera).'' Physiological and Biochemical Zoology, 79, 919-926.
  • Duellman, W. E. (2003). ''Helmeted water toad, Caudiverbera caudiverbera.'' Grzimek's Animal Life Encyclopedia, Volume 6, Amphibians. 2nd edition. M. Hutchins, W. E. Duellman, and N. Schlager, eds., Gale Group, Farmington Hills, Michigan.
  • Dunn, E. R. (1931). ''New frogs from Panama and Costa Rica.'' Occasional Papers of the Boston Society of Natural History, 5, 385-401.
  • Stuart, S., Hoffmann, M., Chanson, J., Cox, N., Berridge, R., Ramani, P., and Young, B. (eds) (2008). Threatened Amphibians of the World. Lynx Edicions, IUCN, and Conservation International, Barcelona, Spain; Gland, Switzerland; and Arlington, Virginia, USA.
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Management

Conservation Actions

Conservation Actions
It occurs in several protected areas. The harvesting of this species from the wild needs to be managed sustainably.
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Relevance to Humans and Ecosystems

Risks

Relation to Humans

Helmeted Water Toads are a food source for the Chileans (Duellman 2003).

  • Castañeda, L.E., Sabat, P., Gonzalez, S.P., and Nespolo, R.F. (2006). ''Digestive plasticity in tadpoles of the Chilean Giant Frog (Caudiverbera caudiverbera).'' Physiological and Biochemical Zoology, 79, 919-926.
  • Duellman, W. E. (2003). ''Helmeted water toad, Caudiverbera caudiverbera.'' Grzimek's Animal Life Encyclopedia, Volume 6, Amphibians. 2nd edition. M. Hutchins, W. E. Duellman, and N. Schlager, eds., Gale Group, Farmington Hills, Michigan.
  • Dunn, E. R. (1931). ''New frogs from Panama and Costa Rica.'' Occasional Papers of the Boston Society of Natural History, 5, 385-401.
  • Stuart, S., Hoffmann, M., Chanson, J., Cox, N., Berridge, R., Ramani, P., and Young, B. (eds) (2008). Threatened Amphibians of the World. Lynx Edicions, IUCN, and Conservation International, Barcelona, Spain; Gland, Switzerland; and Arlington, Virginia, USA.
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Wikipedia

Helmeted water toad

The helmeted water toad, Chilean helmeted bull frog or wide-mouth toad (Calyptocephalella gayi, syn. Caudiverba caudiverba) is the sole species of the genus Calyptocephalella in the family Calyptocephalellidae. The only other members of this family are Telmatobufo. The helmeted water toad is found in central Chile, and possibly adjacent west-central Argentina. This very large toad weighs up to 0.5 kg (1.1 lb). It is aquatic and found in deep ponds and small reservoirs. It is threatened by capture for human consumption, habitat loss, pollution, and introduced trout. It is occasionally captured for herpetoculture.

Characteristics[edit]

Their size ranges from 8 to 20 in, and exceptionally found copies of a recessive form reached 75 cm from the end of the head to the end of the leg. Their normal weight range is around 0.5 kg, with exceptions exceeding 3 kg. They are colored yellow, brown, and green, with light green in mature specimens, while the oldest are gray, or have gray patches on a dark background.

Reproduction[edit]

The female lays eggs in water bodies containing abundant vegetation. Larval life lasts about two years. After hatching, larval survival depends on the presence of vegetation as the existence of movements in the body of water maintain good oxygenation, but the presence of seasonal ponds with some degree of drainage is essential for hatching, as these sites contain fewer predators to the larvae. Then, the transport of larvae from ponds, to larger bodies of water during the rains, or transport of these among several bodies of water facilitates the survival and allows a good development of populations. The larvae prefer cooler areas of the body of water and protective aquatic vegetation, unlike toad larvae that occupy the same sites and have a higher degree of pigmentation that protects them from the solar rays.

Feeding[edit]

Their food in the larval stage is vegetation. In adult form, they vary their diets to live animal prey, feeding on fish, invertebrates, birds, and small rodents, and even cannibalism.

State of conservation[edit]

It is in Vulnerable according to IUCN, due mainly to the introduction of Xenopus laevis (known in Chile as the African toad), a species that has affected, as in other parts of the world, local amphibians when carrying the chytrid fungus Batrachochytrium dendrobatidis, which passes through the skin of amphibians not adapted to it. Their cells react to the pathogen, causing hardening and, therefore, hyperkeratosis and death by asphyxiation. The fungus has been classified as a major factor in the decline in amphibian populations worldwide, but in Chile has been reported recently, in 2009. Other causes cited are competition that occurs between X. laevis and Chilean frog, introduced for sale in the market for frog legs.

References[edit]

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