Japanese common sea cucumber Apostichopus japonicus is one of the most important fisheries species of the world, while the natural resources are declining recently. We examined the retention rate of single spaghetti tags applied to A. japonicus to use future mark-recapture studies for estimating their stocks and/or their ethology. Eight of 10 individuals retained the tags for 76 days under 12°C. The retention rate is high compared to the other studies using spaghetti tags on Aspidochirotida, and that is practical levels to utilize for ecological and/or conservation studies in the active and reproductive season of A. japonicus.
