The sword-tail newt, sword-tailed newt, yellow-bellied newt, or Okinawa newt (''Cynops ensicauda'') is a species of true salamander from the

Ryukyu Archipelago The , also known as the or the , are a chain of Japanese islands that stretch southwest from Kyushu to Geography of Taiwan, Taiwan: the Ōsumi Islands, Ōsumi, Tokara Islands, Tokara, Amami Islands, Amami, Okinawa Islands, Okinawa, and Sakis ...

in Japan. It has recently been placed on Japan's Red List of Threatened Amphibians. Sword-tail newts are poisonous, and may also be referred to as fire-bellied newts due to the orange coloration of their underside. They are not to be confused with the common

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...

and

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 ...

species. It is distinguished from these two species by their larger size, broader heads and smoother skin. Its coloration ranges from brown to black, occasionally with an orange dorsal stripe. Some individuals may have light spotting or speckling on their backs. Sword-tailed newts can reach in males and in females.Caudata Culture Species Entry - Cynops ensicauda
/ref> They are the largest living members of their genus. They exhibit

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 ani ...

. Females’ tails are longer than the rest of their body; those of males are much shorter, and sometimes display a whitish sheen during breeding season.

Habitat and distribution

The sword-tailed newt is only found on the

, an island chain off the southern coast of Japan, as well as on many smaller surrounding islands. The newts typically live in cool, stagnant bodies of water. They are commonly found in man-made structures such as rice paddies, road-side ditches, and cattle waterholes. The two known subspecies of sword-tailed newt are ''C. e. ensicauda'' and ''C. e. popei''. Due to the

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...

climate of its native habitat, it is more tolerant of high temperatures than other ''Cynops''. The sword-tailed newt has no natural predators, thus deforestation and land development are the main causes of their endangerment. As of 2010, breeding grounds were visited by 75% less newts than in 1996. Many of their breeding sites are in roadside ditches and gutters, and they are highly territorial, making it difficult to relocate them.

Trends and threats

The populations of ''C. ensicauda'' have declined in recent years, especially as a result of habitat destruction due to land development. Large predatory fish of the genus ''

Tilapia Tilapia ( ) is the common name for nearly a hundred species of cichlid fish from the coelotilapine, coptodonine, heterotilapine, oreochromine, pelmatolapiine, and tilapiine tribes (formerly all were "Tilapiini"), with the economically most ...

'' have been introduced into traditional breeding ponds. Even in locations where suitable forest habitat has been preserved, the construction of access roads with concrete drainage ditches kills many; the newts wander to forage on rainy days and may fall into the ditches, where they will die when the rain ceases (Goris and Maeda 2004).

References

External links

Caudata Culture caresheet and photos of Swordtail Newt
{{Taxonbar, from=Q393887 Cynops Endemic amphibians of Japan Endemic fauna of the Ryukyu Islands Amphibians described in 1861 Taxa named by Edward Hallowell (herpetologist)