Individual tracking to specify the aestivation site of adult sea cucumber Apostichopus japonicus on a jetty in Yoshimi Bay, western Yamaguchi Prefecture, Japan

Abstract

To specify the aestivation site of Apostichopus japonicus, an individual tracking survey was carried out in the jetty in Yoshimi Bay, western Yamaguchi Prefecture. Ten marked animals were released and continuously tracked for one summer. Their aestivation sites were not in the mud that was once considered as the main aestivating habitat of this species, but in the narrow space between shells on the steel sheet-pile wall in the bend of the jetty, and the undersurface of the overhang-structure in the quay. We conclude that underneath of the rock tracts and boulder stones are the natural aestivating habitats.