Species information
Scientific name: Satsuma eucosmia eucosmia
Japanese name: オキナワヤマタカマイマイ
Chinese name: 沖繩高腰蝸牛
English name: Satsuma eucosmia eucosmia
Origin: Okinawajima, Hamahigajima
Ecology and description
Satsuma eucosmia is an arboreal land snail with the following two subspecies:
- S. e. eucosmia (nominate subspecies): It occurs on Okinawajima and Hamahigajima. The shell is about 21–30mm in diameter, and its height often exceeds its diameter. There are three basic shell patterns: pale white with a yellowish suture and base; two bands on the periphery; and dark bands above and below the periphery that fade to yellowish red toward the suture and base. Individuals in northern Okinawajima show additional patterns.
- S. e. erabuensis: It occurs on Okinoerabujima in the Amami Islands. The shell is about 26–30mm in diameter and 19–26mm high, so its height does not exceed its diameter and the shell is flatter. The shell is pale yellow with a broad purplish-brown band above the periphery and another below it, and it shows no individual variation in color.
S. e. eucosmia occurs in two isolated areas of Okinawajima, one in the north and one in the south, and is absent from the Motobu Peninsula and from the central part of the island, from Yomitan and Uruma to Urasoe and Okinawa City. The genital morphology of the northern and southern populations differs slightly.
Satsuma largillierti occurs on Okinawajima north of Urasoe, where it shares its range with S. e. eucosmia in the north. The shells of the two species are difficult to tell apart by appearance, and their genitalia must be examined.
Takeuchi et al. (2001) surveyed the arboreal snails of the subgenus Satsuma (Luchuhadra) in the Ryukyu Islands from 1996 to 1999. At that time, S. eucosmia and S. largillierti had not yet been separated and were treated together as S. largillierti. These snails on Okinawajima live in natural forest and have also been found in woodland within farmland. They lay their eggs in the leaf mold inside hollows in the trunks or branches of Ficus virgata, or in hollows in adjacent limestone.
References: Kameda, Yuichi, and Makoto Kato. “Systematic Revision of the Subgenus Luchuhadra (Pulmonata: Camaenidae: Satsuma) Occurring in the Central Ryukyu Archipelago.” Venus: Journal of the Malacological Society of Japan, vol. 66, no. 3–4, 2008, pp. 127–145. doi:10.18941/venus.66.3‑4_127
Takeuchi, Masatoshi, Yukio Komine, and Masashi Nomura. “Geographical Distribution and Habitat Characteristics of the Arboreal Land Snail Subgenus Luchuhadra in the Ryukyu Islands, Japan.” Wildlife Conservation Japan, vol. 6, no. 2, 2001, pp. 91–107.
Field photographs taken during our tours, with observation dates
You may see this snail on our 【Forest Walk】 or 【Herping】 tours.
