Lumbrineris latreilli (Audouin et Milne-Edwards)の生殖行動と若虫の分散

抄録

Previous studies (Nishihira et al., 1980; Sato et al., 1982; Tsuchiya et al., 1982) on the breeding ecology of the polychaete, Lumbrineris latreilli (Audouin et Milne-Edwards) were summarized and reproductive strategy was discussed. The worm was restricted to the patches of Zostera marina L. on the fine sediments and patches of Sargassum and other algae growing on pebbly bottom. When water temperature rises up to about 16°C, many breeding individuals come up on the algae to liberate gavietes around high tides at night. The worms select spawning site on the sea weeds growing at, or just near, their living place, and tend to attach egg masses to the sea weeds as high as possible. The local population in a certain area spawns almost simultaneously (2-3 days). Fertilized eggs develop into juveniles through trochophore within a jelly mass and the young emerge little by little over a period of about 20 days in a closed shore, so the stage of development at emergence varies from 3- to 10-setiger stage. It was estimated that 60-70% or more of spawn eggs became potential recruits around the spawning site, but the number of young actually collected in the field was about 1/3 of the estimated figure.