Overview

Comprehensive Description

Description

Hynobius stejnegeri has a snout to vent length of 76-85 mm and a total length of 137-155 mm. Compared to other Japanese Hynobius, this is a large, very robust salamander. Individuals of nearly 200 mm in total length have been reported. It has 13, but sometimes 14, costal grooves. Both its limbs and toes are short. When its limbs are adpressed to the flank, there is a space of 2-3.5 costal grooves between the fore and hind toes. True to its common name, its dorsal surface has an almost translucent blackish brown ground color blotched with bright amber. Its ventral surface is lighter and without blotches.

Since the amber blotches fade in fixative, preserved specimens of H. stejnegeri are easily confused with Hynobius naevius, with which this species is sympatric. In life it can be distinguished by the amber color of its blotches, as compared to the silver or whitish blotches of H. naevius. Also, in H. naevius, the blotches are like dots on the top of the back which become larger on the flanks and tail. In H. stejnegeri, the blotches are generally largish all over the dorsal surfaces (Goris 2004).

Hynobius stejnegeri is sympatric with H. naevius throughout its range, no intergrades are known, suggesting strong reproductive isolation (Goris 2004).

  • Goris, R.C. and Maeda, N. (2004). Guide to the Amphibians and Reptiles of Japan. Krieger Publishing Company, Malabar, Florida.
  • IUCN, Conservation International, and NatureServe. 2006. Global Amphibian Assessment. < www.globalamphibians.org >. Accessed on 28 November 2006.
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Distribution

Range Description

This species is endemic to Japan, and is distributed in Kyushu (Kumamoto, Miyazaki, and Kagoshima Prefectures).
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Distribution and Habitat

Hynobius stejnegeri is found only in Kyushu, in the mountainous areas of the prefectures of Kumamoto, Miyazaki, and northern Kagoshima. It lives in broad-leaved evergreen or mixed forests (Goris 2004).

  • Goris, R.C. and Maeda, N. (2004). Guide to the Amphibians and Reptiles of Japan. Krieger Publishing Company, Malabar, Florida.
  • IUCN, Conservation International, and NatureServe. 2006. Global Amphibian Assessment. < www.globalamphibians.org >. Accessed on 28 November 2006.
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Physical Description

Type Information

Holotype for Hynobius stejnegeri
Catalog Number: USNM 23901
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Amphibians & Reptiles
Sex/Stage: Female;
Preparation: Ethanol
Year Collected: 1884
Locality: Kumamoto, Higo Province, Kumamoto Prefecture, Kyushu Island, Japan, Asia
  • Holotype: Dunn, E. R. 1923. Proc. Calif. Acad. Sci. 12 (2): 28.
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Ecology

Habitat

Habitat and Ecology

Habitat and Ecology
It occurs in broad-leaved evergreen forest and mixed forest. It breeds in upstream areas, where the larvae also develop.

Systems
  • Terrestrial
  • Freshwater
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Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
VU
Vulnerable

Red List Criteria
B1ab(iii)

Version
3.1

Year Assessed
2004

Assessor/s
Yoshio Kaneko, Masafumi Matsui

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

Contributor/s

Justification
Listed as Vulnerable because its Extent of Occurrence is less than 20,000 km2, its distribution is severely fragmented, and there is a continuing decline in the extent and quality of its habitat.

History
  • 1996
    Data Deficient
  • 1994
    Rare
    (Groombridge 1994)
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Population

Population
There is no information on the population status of this species.

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

Hynobius stejnegeri breeds near the headwaters of mountain brooks from the end of April to the middle of May. It lays an exceptionally long pair of eggs sacs which are 20-30 cm in length and contain a total of 16-57 eggs. The female remains near the sacs until the eggs hatch. If the female is experimentally removed, the eggs eventually disappear, presumably eaten by freshwater crabs or other animals. The larvae have claws and live in the stream until they metamorphose and emerge in September to October of the year of birth. Many larvae overwinter in the stream and emerge in spring to summer of the following year (Goris 2004).

  • Goris, R.C. and Maeda, N. (2004). Guide to the Amphibians and Reptiles of Japan. Krieger Publishing Company, Malabar, Florida.
  • IUCN, Conservation International, and NatureServe. 2006. Global Amphibian Assessment. < www.globalamphibians.org >. Accessed on 28 November 2006.
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Threats

Major Threats
The major threats are habitat loss and degradation, due to the construction of roads and logging, and water pollution. This species is also harvested for medicine and food.
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Life History, Abundance, Activity, and Special Behaviors

Major threats to Hynobius stejnegeri include the construction of roads, deforestation, erosion and pollution. This species is protected in the Kumamoto Prefecture as a natural monument (IUCN 2006).

  • Goris, R.C. and Maeda, N. (2004). Guide to the Amphibians and Reptiles of Japan. Krieger Publishing Company, Malabar, Florida.
  • IUCN, Conservation International, and NatureServe. 2006. Global Amphibian Assessment. < www.globalamphibians.org >. Accessed on 28 November 2006.
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Management

Conservation Actions

Conservation Actions
It is designated a natural monument by Kumamoto Prefecture. There is a need to ensure that the offtake of this species from the wild is managed sustainably.
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Relevance to Humans and Ecosystems

Risks

Relation to Humans

Hynobius stejnegeri is used for medicine and food (IUCN 2006).

  • Goris, R.C. and Maeda, N. (2004). Guide to the Amphibians and Reptiles of Japan. Krieger Publishing Company, Malabar, Florida.
  • IUCN, Conservation International, and NatureServe. 2006. Global Amphibian Assessment. < www.globalamphibians.org >. Accessed on 28 November 2006.
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Wikipedia

Amber salamander

The amber salamander (Hynobius stejnegeri) is a species of salamander in the Hynobiidae family, endemic to Japan. Its natural habitats are temperate forests and rivers. It is threatened by habitat loss.

Contents

Physical characteristics

As its name suggests, the external appearance is that of semitransparent blackish brown ground color, blotched with bright amber. Its ventral surface is lighter and without blotches.[3] The amber salamander has a snout-to-vent length of 76–85 mm and a total length of 137–155 mm. However, individuals have been reported to have been nearly 200 mm in length.[4] The head appears to be oval when viewed from above and the eyes are prominent, and a gular fold is present. It has a robust and cylindrical body with 13 to 14 costal grooves.[5][6] It is similar to Boulengeri kimurae in color, but has only four toes, a longer series of vomerine teeth, and a longer body.[7][2]

Habitat and ecology

This species of salamander is found only in Kyushu, Japan, and is distributed among the mountainous areas of the prefectures of Kumamoto, Miyazaki, and Northern Kagoshima.[3][1] The various regional populations of the amber salamanders are separated by a number of geographic barriers, including the Gokase River and the Aso Volcano, the Kirishima Volcano, and the Yatsushiro Sea.[8] It can be found in both terrestrial (land) and freshwater ecosystems.[1] Its land habitat is located in temperate forests which consist of mountainous areas of broad-leaved, evergreen forests, as well as mixed forests.[7][1] The freshwater habitat is located in wetlands of permanent rivers, streams, and creeks, including waterfalls.[1] Habitats have been discovered in and around mountainous streams at altitudes ranging from 500–1500 m.[8] They return to upstream areas to breed, and this is also where the larvae develop.[3] Their diets are made up of insects, spiders, worms, aquatic insect larvae, and crustaceans, and they have been known to resort to cannibalism.[8] The unique possible cryptic coloration is hypothesized to act as a camouflage among fallen leaves. If the color pattern is an effective deterrent from predators, then this characteristic is likely due to strong selection.[8] A genetic variance of 4% was found to be due to phenological circumstances in the populations of amber salamander between two regions separated by geographic isolation.[8]

Behavior

The egg sacs produced by the males are quite long, ranging from 17 to 30 cm and differ from other species of the same genus, Hynobius boulengeri, by not having the prominent whip-like formation on the free end.[7] Each clutch ranges from 21–57 eggs, and the female remains close to her clutch until the eggs have hatched.[4] The hatched larvae are a yellowish color and the fingers and toes sport black claws.[7] These larvae undergo a metamorphosis while living in the stream, and emerge in September and October of the same year they are laid, but many wintering larvae remain in the stream until spring or summer of the following year when they emerge.[4][7]

Threats

The amber salamander is harmed by hunting and trapping, logging, and wood harvesting.[1] Major threats also include the construction of roads, deforestation, erosion, and pollution. The amber salamander is also used for medicine and food.[1][4] H. stejnegeri is also used in the medical field of comparative hepatology.[9] In an experiment, when the mother was removed, the eggs vanished, presumably eaten by freshwater crabs or some other predator.[3][5] This suggests survival of the larvae is contingent on the mother’s protection.

Conservation

The extent of occurrence is less than 20,000 km2, the species are fragmented in distribution, regionally only in Japan, with a continuing decline in the extent and quality of their habitat.[1] The amber salamander was considered near threatened by the Environment Agency of Japan in 2000.[7] It was later determined vulnerable by the International Union for Conservation of Nature (IUCN) in 2010.[1] Now, the amber salamander is on the Earth’s Endangered Creatures List.[10] It is designated a natural monument by Kumamoto Prefecture. There is a need to ensure the capture of this species from the wild is managed in a sustainable way.

References

  1. ^ a b c d e f g h i Yoshio Kaneko, Masafumi Matsui (2004). Hynobius stejnegeri. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2.
  2. ^ a b Dunn, E.R. (1923). "The Salamanders of the Family Hynobiidae". Proc. Amer. Acad. Arts and Sci. 58 (13): 445–523. doi:10.2307/20026019. JSTOR 20026019. 
  3. ^ a b c d Facts about Amber-coloured Salamander (Hynobius stejnegeri). Encyclopedia of Life. Retrieved Oct 25, 2012
  4. ^ a b c d Winters, N. (2006–1207). AmphibiaWeb – Hynobius stejnegeri. Retrieved Oct 25, 2012
  5. ^ a b Goris, R.C. and Maeda, N. (2004). Guide to the Amphibians and Reptiles of Japan. Krieger Publishing Company, Malabar, Florida ISBN 1-57524-085-8.
  6. ^ Thorn, R., (1969). Les salamandres d’Europe, d’Asie et d’Afrique du Nord. Editions Paul Lechevalier, Paris.
  7. ^ a b c d e f Sparreboom, M. (2011-03-14). Science. naturalis – stejnegeri. Retrieved Oct 25, 2012
  8. ^ a b c d e Nishikawa, K., Matsui, M. & Tanabe, S. (2005). "Biochemical Phylogenetics and Historical Biogeography of Hynobius Boulengeri and H. Stejnegeri (Amphibia: Caudata) from the Kyushu Region, Japan". Herpetologica 61: 54. doi:10.1655/03-89. 
  9. ^ Akiyoshi, H., & Inoue, A. M. (2012). "Comparative histological study of hepatic architecture in the three orders amphibian livers". Comparative Hematology 11: 2. doi:10.1186/1476-5926-11-2. 
  10. ^ Glenn, C. R. (2006). Earth's Endangered Creatures – Worldwide Endangered Species List – Animals. Retrieved Oct 25, 2012
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