Nagasaki Prefectural Institute of Fisheries, Nagasaki 851-2213, Japan
This study evaluated the stock effectiveness of hatchery-produced ocellate puffer by sampling survey in Ariake Sound where mature puffer are landed. In 1,584 samples, 85 marked puffer were observed, and were judged to be from age 2 to 8 years old (mainly 3 years old) from marked otolith by alizarin complexone and/or tetracycline. The recapture rate of released seeds (3-100 mm in total length) was estimated to be 0-0.41%, and corresponded to release size. The von Bertalanffy growth equations were fitted as Lt=63.3{1−exp [−0.245(t＋0.192)] for male, and Lt=75.0{1−exp [−0.130(t＋2.13)] for female, where t is age (year) and Lt is total length (cm) at the age. All recaptured puffers had matured similar to wild puffer judged from GSI. These results suggest that hatchery-produced ocellate puffer returned to Ariake Sound by homing ability to the same natal spawning ground.