The Yuriyagai: J. Malacozool. Ass. Yamaguchi, 8(1). December 2001

Original Articles

Distribution and seasonal maturation of the alien slug Lehmannia valentiana (Gastropoda: Pulmonata: Limacidae) in Yamaguchi Prefecture, Japan

Yasunori KANÔ, Hiroshi FUKUDA, Hiroshi YOSHIZAKI, Miyoko SAITÔ, Ken-Ichi HOSAKA, Tomoyuki SUGIMURA, Yasuko F. ITÔ, Hiroji FUJIWARA, Yasuhiro NAKAMURA, Kazuyuki MASHINO, Kenji ITÔ, Kunihiko TONE, Toshikazu FUKUDA, Teruhisa MITOKI, Hiroyoshi YAMASHITA, Shigeo HORI, Kotoe HORI and Hisasuke HORI

Abstract The distribution, morphology and sexual maturity of Lehmannia collected from all districts of Yamaguchi Prefecture are examined. Anatomical characters confirm all the specimens to be Lehmannia valentiana (Férussac, 1822). Some specimens were collected from coastal and mountain areas away from human settlements, indicating that L. valentiana occurs in relatively undisturbed environments as well as in urban areas. This species is a potential agricultural pest, as it feeds on fresh leaves of green plants. In Yamaguchi Prefecture, adults were found from September to May. L. valentiana hatches in winter and spring and lives for slightly longer than one year. As it ages, the skin becomes deep brown, the reticulate pattern of the dorsal mantle becomes prominent, and the longitudinal color bands become thinner. Body length is only partly related to age or maturity.

Key words: Madrella, morphology, taxonomy, revision, distribution, Japan.

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New localities for Madrella sanguinea (Angas, 1864) (Gastropoda: Arminoidea: Madrellidae) from the Ariake Inland Sea and the Seto Inland Sea, with a review of records of the Madrellidae of Japan on the Internet


Abstract The first records of the nudibranch species Madrella sanguinea from the Ariake Inland Sea and the Seto Inland Sea are here presented, which make up the first findings from inner-bay habitats. Some differences are recognized in the external morphology between specimens from these two localities. The radula and jaw of the specimen from the Seto Inland Sea were examined and they were different to those of a specimen previously reported from the Ligurian Sea. Access to websites run by SCUBA divers and others has revealed eight new localities for existence of Madrella spp. in Japan. M. gloriosa has, in fact, been photographed in three localities. In Mie Prefecture, M. granularis, or a presumably undescribed species of Madrella, was recorded. Both M. gloriosa and M. granularis have not been recorded after their original descriptions from Sagami Bay. M. sanguinea is here regarded to be distributed southwards from Tsunoshima Island on the Japan Sea coast, and in the Pacific from Sagami Bay southwards to the Okinawa Islands.

Key words: Madrella, morphology, taxonomy, revision, distribution, Japan.

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Discovery of healthy populations of the endangered bivalve Soletellina adamsii Reeve, 1857 (Tellinoidea: Psammobiidae) on the Suô-nada Sea (western Seto Inland Sea) coast of Yamaguchi Prefecture, western Japan, with taxonomic remarks

Jirô HONDA, Richard C. WILLAN, Kôhei SUZUKIDA, Kôichirô MIZOGUCHI and Hiroshi FUKUDA

Abstract Soletellina adamsii Reeve, 1857 (previously misidentified as S. diphos (Linnaeus, 1771) in the Japanese literature) was estimated as an Ågendangered speciesÅh in the Red Data Book by the World Wide Fund for Nature Japan (WWFJ). Recently, we found healthy populations of this species of bivalve at four localities in Aio-chô and Ajisu-chô, both Yamaguchi Prefecture, along the Suô-nada Sea, western Seto Inland Sea. Coastal people at these localities sporadically gather this species, together with S. boeddinghausi (Lischke, 1870), for consumption. At some of these localities, both adults and juveniles were recognized leading to our conclusion that both species breed and recruit there. The present populations can be regarded as precious and very restricted in modern Japan.

Key words: Soletellina adamsii, Soletellina diphos, Bivalvia, Tellinoidea, Psammobiidae, habitat, species diversity, conservation, sandy tidal-flat, Aio-chô, Ajisu-chô, Seto Inland Sea

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Brief Communication

A review of the species of the family Limacidae (Gastropoda: Pulmonata) from Yamaguchi Prefecture, Japan

Yasunori KANÔ

Abstract Records of limacid species from Yamaguchi Prefecture have frequently been impossible to confirm because of the lack of voucher specimens. Here I re-identify species that were originally reported by Kazuyuki Mashino on the basis of his photographs, and review all previous records of limacid species from Yamaguchi Prefecture. Three species are here recorded from the Prefecture: Limax flavus Linnaeus, 1758, Lehmannia valentiana (Férussac, 1822) and Deroceras laeve (Müller, 1774). All are alien species.

Key words: Limax flavus, Lehmannia valentiana, Deroceras laeve, slug, introduced species, re-identification, taxonomy

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