Rana supranarina has a moderately stout body and a triangular head which is longer than wide. Its snout is dorsally sharply pointed and projects beyond the lower jaw, althought females tend to have a more blunt snout. The nostril is midway between the tip of the snout and the eye. Forelimbs are stout and the fingers are unwebbed, with the tips dilated into small discs having circummarginal grooves. The hindlimbs are rather short, about 2.5 times the length of the forelimbs. Its heels overlap when the hindlimbs are held at right angles to the body. The tibiotarsal articulation of an adpressed limb reaches the anterior corner of the eye. The toes are rather well webbed with thick, not crenulate, webs. Toe disks are slightly larger than those of the two outer fingers.
The color in life is fairly variable and individuals have a dorsal color ranging from light brown to greenish brown. The dorsum is smooth, the side of its trunk is coarsely granular, and the chest and abdomen are smooth. This frog has a weak dorsolateral fold and supratympanic folds.
It is the largest species of the Rana narina group, with a snout to vent length of 60-76 mm in males and 82-103 mm in females. R. supranarina occupies the same range as R. utsunomiyaorum, but R. supranarina can be distinguished by its much larger size and longer hind legs.
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Japan
Rana supranarina is found on the two southern islands of Ishigakijima and Iriomotejima, living along brooks in mountain forests. Unlike R. utsunomiyaorum, it is found not only along mountain streams but also in riverside forests just outside mangrove vegetation only several meters above sea level.
Life History, Abundance, Activity, and Special Behaviors
The breeding habits of R. supranarina are the same as for R. narina except that the breeding season begins earlier. Some populations of R. supranarina breed at the beginning of October and others as late as the end of March, with the peak of breeding in late December to early January.
Males have a pair of vocal sacs and a pair of vocal openings just inside the corners of the mouth. The mating call is said to be a short unpulsed note with extreme frequency modulation.
Breeding occurs in high altitude water basins and in spring pools along brooks in foothills. Egg masses are attached to stones or dead leaves under the water in a shallow stream or in a pool. Eggs are yellowish white in color and laid in a compact gelatinous mass consisting of two layers. There are about 1100 eggs in a clutch. The mean diameter of ova ranges from 2.6 to 2.9 mm. Tadpoles of this species have been found at the breeding sites. They are rather slender in shape, with a long, muscular tail. Both body and tail are low in height. The spiracle is sinistral and the dental formula is 2:3+3/3:1+1 when fully grown. They reach 50 mm in total length.
Possible reasons for amphibian decline
General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
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.
Originally submitted by: Nichole Winters (first posted 2007-04-17)
Edited by: Kellie Whittaker (2007-06-04)
Species Account Citation: AmphibiaWeb 2007 Odorrana supranarina: O-hanasakigaeru <https://amphibiaweb.org/species/5160> University of California, Berkeley, CA, USA. Accessed May 18, 2021.
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Citation: AmphibiaWeb. 2021. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 18 May 2021.
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