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| Microhyla kuramotoi Matsui & Tominaga, 2020 DOI: 10.5358/hsj.39.120 |
Abstract
A Japanese microhylid, Microhyla okinavensis, originally described from Okinawajima Island, middle Ryukyus, was long synonymized with M. ornata from India. However, molecular phylogenetic studies revealed its distinct species status from M. ornata, and more recent phylogenetic study revealed the population from the Yaeyama Group of the southern Ryukyus to be a sister taxon to Chinese M. mixtura and not to populations from the remaining group of the Ryukyus, that are sister to another Chinese species, M. beilunensis. The Yaeyama and the remaining Ryukyu populations greatly differ phylogenetically, although less clearly morphologically. From these data, we consider the Yaeyama population as a species distinct from M. okinavensis from the middle Ryukyus.
KEYWORDS: Microhyla beilunensis, Microhyla fanjingshanensis, Microhyla mixtura, Microhyla okinavensis, new species, Yaeyama Group
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| Dorsal (A) and ventral (B) views of male holotype of Microhyla kuramotoi sp. nov. (RUMF-ZH-01017). Scale bar = 5 mm. |
Systematics
Microhyla kuramotoi sp. nov.
[Japanese name: Yaeyama-Himeama-Gaeru]
[English name: Yaeyama Narrow-Mouthed Toad]
Microhyla okinavensis Stejneger, 1907, p. 89, (part); Parker, 1934, p. 138, (part); Okada, 1966, p. 42 (part).
Microhyla fissipes Okada, 1930, p. 63 (part); Okada, 1931, p. 71 (part).
Microhyla ornata Gressitt, 1938, p. 164, (part); Inger, 1947, p. 324 (part); Nakamura and Uéno, 1963, p. 66 (part).
Diagnosis: A member of the Microhyla fissipes species group of Garg et al. (2019), which is distinguished from other Microhyla groups by; small to medium-sized adults; nostrils placed towards the lateral sides of the snout; finger and toe tips rounded; terminal phalanges of toes knobbed or T-shaped; inner metatarsal tubercle present, elongate; outer metatarsal tubercle small, rounded; webbing between toes rudimentary; dorsal skin shagreened to sparsely granular; a narrow mid-dorsal line extending from tip of the snout to the vent.
Etymology: The specific name is dedicated to Dr. Mitsuru Kuramoto, Emeritus Professor of the Fukuoka University of Education, for his great contributions to Asian amphibian biology, including the fauna of the southern Ryukyus.
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| Map of East Asia (A) and Ryukyu Islands (B), showing distribution of Microhyla species. Open circle and obliquely hatched area: Microhyla kuramotoi sp. nov., reverse triangle and vertically hatched area: M. okinavensis, closed circle: M. beilunensis, closed triangle: M. fanjingshanensis, closed square and finely dotted area: M. mixtura, horizontally hatched area: M. fissipes. |
Range: Yaeyama Islands of Southern Ryukyus, Okinawa Pref., Japan: Ishigakijima Is., Taketomijima Is., Kohamajima Is., Iriomotejima Is., and Haterumajima Is. Artificially introduced into Kuroshima Is.
Natural history: Microhyla kuramotoi sp. nov. occurs from lowlands to montane regions, and lives on the ground among leaf litter and grasses. The breeding season extends almost the entire year, but is usually intensive from February to October. Film-like egg mass is laid on the surface of various bodies of still waters including ponds, rice fields, temporary pools, and sometimes slowly flowing small streams. Eggs are dark yellowish brown in the animal hemisphere. Females collected from Iriomotejima Is. and Kohamajima Is., respectively, contained 624–1207 (mean=916.9) and 271–890 (528.9) mature ova of 1.0–1.3 (mean=1.2) mm in diameter (Matsui and Ota, 1984 as M. ornata). Larvae form a cohort, swimming slowly in the middle and upper layers of water sucking in plankton.
Masafumi Matsui and Atsushi Tominaga. 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. DOI: 10.5358/hsj.39.120
