Japan Sea-Farming Association, Tamano Station, Tamano, Okayama 706-0002, Japan
Suitable materials and structures with application to artificial nursery reefs for releasing artificially reared juveniles of the red spotted grouper Epinephelus akaara were studied experimentally. Experiments using four kinds of miniature reefs were conducted to study their ability to attract the juveniles and to protect them from predators. The juveniles preferred the miniature reefs with smaller space to those with larger space under reared conditions. This corresponded to the behavior of wild juveniles which might avoid predators by hiding in small holes or crevices. The miniature reefs with smaller space effectively hindered the scorpion fish Sebastiscus marmoratus from taking the juveniles. Artificial nursery reefs for juvenile red spotted grouper should have proper smaller spaces to attract the juveniles and to avoid predation.