@article{oai:mie-u.repo.nii.ac.jp:00010312,
 author = {Ozawa, Hiroyuki and 小澤, 宏之 and Kimura, Taeko and 木村, 妙子 and Sekiguchi, Hideo and 関口, 秀夫},
 issue = {3},
 journal = {Venus : the Japanese journal of malacology},
 month = {Sep},
 note = {application/pdf, The tropical mussel Modiolus philippinarum is common and abundant in seagrass beds in Okinawa Island, southernmost Japan, and is commercially important to local fishermen. In order to elucidate the mechanisms that maintain the difference in density between benthic populations of the mussel within and outside seagrass beds, we monitored temporal variations in densities of the mussel at different developmental stages (planktonic larvae; new settlers; small and large individuals) within and outside seagrass beds in Okinawa Island over one year. Based on these data, the difference in larval density was not significant, but there were significant differences between densities of new settlers (shell length<250μm), small individuals (250μm≦shell length<1.0mm) and large individuals (shell length≧1.0mm), within and outside seagrass beds. Cohort separation was applied to data for shell length distributions of new settlers and small and large individuals, and revealed that larvae mainly settled in July to August. New settlers grew up to about 20 mm in shell length in their first year; their mortality was constant and/or low once individuals had attained shell lengths of about 300μm. These facts indicates that the much higher density of benthic populations of the mussel within seagrass beds may be determined at and/or shortly following larval settlement, though details of the mechanisms driving the above difference are not yet identified., ホソスジヒバリガイは沖縄本島では主として海草藻場に生息し,隣接する海草のない区域にはほとんど見られない。この海草藻場内外のホソスジヒバリガイの密度差が形成され維持される機構を解明するために,沖縄本島の金武湾の海草藻場内外に定点を設け,各成長段階(浮遊幼生,海底稚貝,小型個体,大型個体)の密度の変動を1年間にわたって調査した。海草藻場内外のホソスジビバリガイの密度差は,浮遊幼生を除いて,各成長段階において統計的に有意であった。ホソスジビバリガイの殼長頻度分布に基づくコホート解析の結果によれば,浮遊幼生は主として7月〜8月に着底し,着底後1年で約20mmにまで成長する。着底直後の死亡率は著しく高いが,殼長約300μmを越す小型個体の死亡率は低くなり,ほぼ一定となる。これらの事実は,その具体的な詳細は未解明であるが,海草藻場内のホソスジヒバリガイの大型個体の密度は着底直後の死亡率の高低によって決定されており,また海草藻場内外の密度差は着底稚貝の段階において決定されていることを示している。},
 pages = {203--220},
 title = {Larval Recruitment of the Tropical Mussel Modiolus philippinarum (Bivalvia: Mytilidae) in Seagrass Beds},
 volume = {65},
 year = {2006}
}