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

true salamander Salamandridae is a family of salamanders consisting of true salamanders and newts. 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 v ...

from the Ryukyu Archipelago 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 and Japanese 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. 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 Ryukyu Archipelago, 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'' 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)