Breeding season and life history of Lingula anatina after settlement in Amami-Oshima Island, Kagoshima, Japan

抄録

Lingula species are brachiopods inhabiting the tidal flats. In Japan, they are threatened by the marine pollution and decreasing habitat. Although these brachiopods are endangered in Japan, little is known about their life history. The aim of this study was to examine the life history characteristics of Lingula anatina after settlement in Kasari Bay, Amami-Oshima Island, Kagoshima, Japan, by measuring the gonad index and seasonal changes in size distribution. The results revealed that the breeding season of this species is from summer to early autumn, which is longer than that of other populations in Japan. Their settlement starts in winter after the planktonic stage, and they reach maturity after two or three years. Their longevity is more than four years and they breed every year. Lingula species are under taxonomic revision; therefore, for convenience, we named the species in Amami-Oshima as Lingula anatina.