Description
Rana amamiensis has a moderately slender body and a triangular head which is longer than wide. Its snout is dorsally pointed and projects beyond the lower jaw, with the nostril nearer to the tip of the snout than to the eye. Forelimbs are stout and the fingers are unwebbed, with the tips dilated into small discs with circummarginal grooves. Hindlimbs are rather long, about 2.9 times the length of a forelimb. The heels overlap when the limbs are held at right angles to the body. The tibiotarsal articulation of an adpressed limb reaches far beyond the tip of the snout. Toes are well webbed with thick, not crenulate, webs. The discs on the toes are as wide as those of the two outer fingers. SVL is 57-69 mm in males and 76-101 mm in females.

R. amamiensis frogs have a dorsal color ranging from light brown to greenish, with some individuals lacking dark dorsal markings. The dorsum has tubercles on the sacrum, while the side of the trunk is coarsely granular, and the chest and abdomen are smooth. There is a feeble dorsolateral line formed by short ridges. The supratympanic folds are weak.

R. amamiensis is similar to R. narina in that the inner side of the dorsolateral fold is usually lighter than the ground color. (This condition is never seen in the remaining species of the Rana narina group.) However, R. amamiensis is much larger than R. narina. There is no other large frog within its range that has such a long snout with nostrils at the tip.

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Japan

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (1 records).

R. amamiensis is found on the two islands of Amami Oshima and Tokunoshima, living along brooks in mountain forests. It can also be seen on mountain trails and it rarely descends to lowlands.

Life History, Abundance, Activity, and Special Behaviors
The breeding habits of R. amamiensis are similar to those of R. narina except for the season. Some populations of R. amamiensis may breed as early as mid-October and others as late as the beginning of May. They lay about 1500 eggs per clutch. The eggs are yellowish white. R. amamiensis tadpoles from Tokunoshima Island are more slender in shape and less pigmented by guanophores than R. supranarina tadpoles. They have a dental formula of 1:4+4/3:1+1.

Males have a pair of vocal sacs and a pair of vocal openings just inside the corners of the mouth. Their mating call is said to consist of two notes. The first is a short unpulsed note which, after a short interval, is followed by a longer unpulsed note.

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Dams changing river flow and/or covering habitat
Subtle changes to necessary specialized habitat
Local pesticides, fertilizers, and pollutants
Predators (natural or introduced)

References

Goris, R.C. and Maeda, N. (2004). Guide to the Amphibians and Reptiles of Japan. Krieger Publishing Company, Malabar, Florida.

Matsui, M. (1994). ''A taxonomic study of the Rana narina complex, with description of three new species (Amphibia: Ranidae).'' Zoological Journal of the Linnean Society, 111(4), 385-415.

Species Account Citation: AmphibiaWeb 2007 Odorrana amamiensis: Amami Hanasakigaeru <https://amphibiaweb.org/species/4974> University of California, Berkeley, CA, USA. Accessed Dec 22, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 22 Dec 2024.

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