Sword-tail newt

The sword-tail newt (Cynops ensicauda) is an endangered species of true salamander from the Ryukyu Archipelago in Japan. It has recently been placed on Japan's Red List of Threatened Amphibians. Sometimes, sword-tail newts are called fire-bellied newts, not to be confused with the common Chinese and Japanese species, because of their bright orange bellies, which serve as a warning to predators that they are poisonous. They can be differentiated from these two species by their large size, broader heads and (against Japanese fire-bellies) smoother skin. This newt ranges from brown to black above, occasionally with an orange dorsal stripe. Some individuals may have light spotting or speckling on their backs.

Sword-tailed newts can reach 12.8 cm (5.0 in) in males and 18 cm (7.1 in) in females.[2] They are the largest living members of their genus.[2] Females and males look significantly different in appearance. Females have much longer tails that are actually longer than the rest of their bodies. Males’ tails are much shorter and sometimes display a whitish sheen during breeding season.

Sword-tail newt
Cynops ensicauda popei001
C. e. popei
Scientific classification
C. ensicauda
Binomial name
Cynops ensicauda
(Hallowell, 1860)
  • Triturus (Cynops) pyrrhogaster ensicaudus (Nakamura and Ueno, 1963)
  • Triturus ensicauda (Sato, 1943)
  • Triturus ensicaudus ensicaudus (Inger, 1947)
  • Triturus ensicaudus popei (Inger, 1947)
  • Triturus ensicaudus (Dunn, 1918)
  • Triturus pyrrhogaster ensicaudus (Kawamura, 1950)

Habitat and distribution

The sword-tailed newt is only found on the Ryukyu Archipelago, an island chain off the southern coast of Japan, as well as on many smaller surrounding islands. This newt's habitat is slow, cool, stagnant bodies of water. They are commonly found in man-made structures such as rice paddies, road-side ditches, and cattle waterholes.[2] The two known subspecies of sword-tailed newt are C. e. ensicauda and C. e. popei. Due to the subtropical climate of its native habitat, it is more tolerant of high temperatures than other Cynops. The sword-tailed newt has no predators, so deforestation and land development are the main reasons for their endangerment.

Breeding places are being frequented by only a fourth of the population that was breeding 14 years ago. This lack of breeding is another key reason for them becoming endangered. Many of their breeding places are in roadside ditches and gutters, which can lead to them being run over. Sword-tail newts are extremely territorial, thus making moving their breeding places difficult.

Trends and Threats

The once-teeming populations of C. ensicauda have declined alarmingly in recent years. There has been massive habit destruction, especially of breeding sites, because of land development. Large, voracious fish of the genus Tilapia have been introduced into traditional breeding ponds. Even where supposedly suitable forest habitat has been preserved, the construction of access roads with concrete drainage ditches often proves fatal. The animals wander about to forage on rainy days and tumble into the ditches, where they are baked by the sun when the rain ceases (Goris and Maeda 2004).[3]


  1. ^ "Cynops ensicauda". Amphibian Species of the World 5.5. American Museum of Natural History. Retrieved 8 September 2012.
  2. ^ a b c Caudata Culture Species Entry - Cynops ensicauda
  3. ^ "AmphibiaWeb - Cynops ensicauda". amphibiaweb.org. Retrieved 2017-03-03.

External links

Fire belly newts

The fire belly newts or fire newts are a genus (Cynops) of newts native to Japan and China. All of the species show bright yellow or red bellies, but this feature is not unique to this genus. Their skin contains a toxin that can be harmful if ingested.

List of endangered amphibians

As of September 2016, the International Union for Conservation of Nature (IUCN) lists 848 endangered amphibian species. 13% of all evaluated amphibian species are listed as endangered.

No subpopulations of amphibians have been evaluated by the IUCN.

For a species to be considered endangered by the IUCN it must meet certain quantitative criteria which are designed to classify taxa facing "a very high risk of exintction". An even higher risk is faced by critically endangered species, which meet the quantitative criteria for endangered species. Critically endangered amphibians are listed separately. There are 1393 amphibian species which are endangered or critically endangered.

Additionally 1567 amphibian species (24% of those evaluated) are listed as data deficient, meaning there is insufficient information for a full assessment of conservation status. As these species typically have small distributions and/or populations, they are intrinsically likely to be threatened, according to the IUCN. While the category of data deficient indicates that no assessment of extinction risk has been made for the taxa, the IUCN notes that it may be appropriate to give them "the same degree of attention as threatened taxa, at least until their status can be assessed."This is a complete list of endangered amphibian species evaluated by the IUCN.

Ryukyu Islands

The Ryukyu Islands (琉球諸島, Ryūkyū-shotō), also known as the Nansei Islands (南西諸島, Nansei-shotō, lit. "Southwest Islands") or the Ryukyu Arc (琉球弧, Ryūkyū-ko), are a chain of Japanese islands that stretch southwest from Kyushu to Taiwan: the Ōsumi, Tokara, Amami, Okinawa, and Sakishima Islands (further divided into the Miyako and Yaeyama Islands), with Yonaguni the westernmost. The larger are mostly high islands and the smaller mostly coral. The largest is Okinawa Island.

The climate of the islands ranges from humid subtropical climate (Köppen climate classification Cfa) in the north to tropical rainforest climate (Köppen climate classification Af) in the south. Precipitation is very high and is affected by the rainy season and typhoons. Except the outlying Daitō Islands, the island chain has two major geologic boundaries, the Tokara Strait (between the Tokara and Amami Islands) and the Kerama Gap (between the Okinawa and Miyako Islands). The islands beyond the Tokara Strait are characterized by their coral reefs.

The Ōsumi and Tokara Islands, the northernmost of the islands, fall under the cultural sphere of the Kyushu region of Japan; the people are ethnically Japanese and speak a variation of the Kagoshima dialect of Japanese. The Amami, Okinawa, Miyako, and Yaeyama Islands have a native population collectively called the Ryukyuan people, named for the former Ryukyu Kingdom that ruled them. The varied Ryukyuan languages are traditionally spoken on these islands, and the major islands have their own distinct languages. In modern times, the Japanese language is the primary language of the islands, with the Okinawan Japanese dialect prevalently spoken. The outlying Daitō Islands were uninhabited until the Meiji period, when their development was started mainly by people from the Izu Islands south of Tokyo, with the people there speaking the Hachijō language.

Administratively, the islands are divided into Kagoshima Prefecture (specifically the islands administered by Kagoshima District, Kumage Subprefecture/District, and Ōshima Subprefecture/District) in the north and Okinawa Prefecture in the south, with the divide between the Amami and Okinawa Islands, with the Daitō Islands part of Okinawa Prefecture. The northern (Kagoshima) islands are collectively called the Satsunan Islands, while the southern part of the chain (Okinawa Prefecture) are called the Ryukyu Islands in Chinese.


Salamandridae is a family of salamanders consisting of true salamanders and newts. Currently, 74 species (with more expected) have been identified in the Northern Hemisphere - Europe, Asia, the northern tip of Africa, and North America. Salamandrids are distinguished from other salamanders by the lack of rib or costal grooves along the sides of their bodies and by their rough skin. Their skin is very granular because of the number of poison glands. They also lack nasolabial grooves.

With a few exceptions, salamandrids have patterns of bright and contrasting colours, most of these are to warn potential predators of their toxicity. They have four well-developed limbs, with four toes on the fore limbs, and (in most cases) five toes on the hind limbs. They vary from 7 to 30 cm (3 to 12 in) in length.All species within the genus Lyciasalamandra are viviparous, meaning they give birth to live young, without a tadpole stage. There are some species within the genus Salamandra are known to be viviparous too. Some newts are neotenic, being able to reproduce before they are fully metamorphosed.


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