Species information
Scientific name: Microhyla okinavensis
Japanese name: ヒメアマガエル
Chinese name: 沖繩小雨蛙、沖繩飾紋姬蛙
English name: Okinawa narrow-mouthed toad
Origin: Amami Islands, Okinawa Islands, and Miyako Islands
Ecology and description
Originally, the Okinawa narrow-mouthed toad and the Taiwanese narrow-mouthed toad were both classified under the South Asian M. ornata. However, a phylogenetic study in 2005 reclassified the Taiwanese population as M. fissipes, and the Ryukyu Islands population as M. okinavensis. A 2020 phylogenetic study further classified the Yaeyama Islands population as M. kuramotoi. Currently, Okinawa narrow-mouthed toad is distributed in the Amami Islands, Okinawa Islands, and Miyako Islands. Okinawa narrow-mouthed toad breeds in the summer (March to July), and during rainy days, the loud calls of males can be heard. However, due to their small size and tendency to hide under fallen leaves and in mud, they are difficult to spot.
Okinawa narrow-mouthed toad tadpoles are active at the water surface, characterized by their translucent bodies and eyes located on the sides of their heads, which distinguishes them from other tadpoles.
References:
Matsui, M., Ito, H., Shimada, T., Ota, H., Saidapur, S. K., Khonsue, W., Tanaka-Ueno, T., & Wu, G. F. (2005). Taxonomic relationships within the Pan-Oriental narrow-mouth toad Microhyla ornata as revealed by mtDNA analysis (Amphibia, Anura, Microhylidae). Zoological Science, 22(4), 489–495.
Matsui, M. (2011). Taxonomic revision of one of the Old World’s smallest frogs, with description of a new genus and three new species (Amphibia: Anura: Microhylidae). Zoological Journal of the Linnean Society, 161(2), 348–402.
Matsui, M., & Tominaga, A. (2020). Distinct species status of a Microhyla from the Yaeyama Group of the Southern Ryukyus, Japan (Amphibia, Anura, Microhylidae). Current Herpetology, 39(2), 120–136.
Field photographs taken during our tours, with observation dates
During our 【Herping】 in the spring season, we often hear Okinawa narrow-mouthed toad calls, and with luck, we may spot an individual calling. On our 【Island Tour】 to Miyakojima in March 2025, we observed many Okinawa narrow-mouthed toad in calm water areas courting.
