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.