Japanese Wrinkled Frogs of the genus Rugosa (sometimes considered a subgenus of Rana or Glandirana) are widespread in Japan and east Asia, as well as Hawaii, where they were introduced in the nineteenth century. They are common at low altitudes (under ~300 m) and can survive in a variety of environments. The Frogs were originally all classified as members of a single species, Rana rugosa, but recent morphological and genetic studies have revealed considerable diversity within the group.
In a paper published in the journal Zootaxa on 7 December 2012, Kunio Sekiya of the Department of Environmental Science at Niigata University, Ikuo Miura of the Institute for Amphibian Biology at Hiroshima University and Mitsuaki Ogata of the Laboratory of Zoo Biology at the Preservation and Research Center in Yokohama describe a new species of Wrinkled Frog from Sado Island, off the north coast of Honshū.
The new species is named Rugosa susurra, from the Latin 'susurrus', meaning whispering, since its call was notable quieter than that of other Frogs in the same area. Rugosa susurra is a 33-45 mm greyish-to-khaki Frog with yellow and white markings in the underside. The females are larger than the males. It has elongated granules (warts) arranged in a linear pattern on its back, giving it a wrinkled appearance. The tadpoles are greyish-brown with white spots. The Frogs were found around rice-fields, ponds and small streams; they apparently do not move far from water. They mate from May to August, laying egg masses which are attached to submerged plants. Both adults and tadpoles hibernate by burying themselves in soft mud under water.
Rugosa susurra. (Top) Adult male. (Middle) Tadpole. (Bottom) Egg mass. Sekiya et al. (2012).
See also How Cow pats help the spread of the Invasive Cane Toad in northern Australia, Three new species of Frog from the Peruvian Andes, New species of Robber Frog from Panama, A cryptic species of Ground Frog from southern Chile and New Spadefoot Toad from southeastern Laos.
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