Census of potential predators and competitors of sandfish, <i>Holothuria scabra</i> , juveniles during floating <i>hapa</i> ocean nursery culture

Predation and competition are among the most important factors affecting sandfish, Holothuria scabra, growth survival in ocean-based production systems. In this study, potential predators competitors of sandfish juveniles reared at two sites Philippines using floating hapa ocean nursery system were assessed. A total 26 species from 16 different families fishes, molluscs crustaceans recorded. These taxa dominated by opisthobranch Stylocheilus striatus Bolinao (north–west Luzon) isopod Cymodoce sp. Maliwaliw (eastern Visayas). Highest number that recruited and/or migrated to inside nets was recorded on day 23 30 Maliwaliw, then decreased over 69-day duration study. Mean length, absolute rates (AGRs) hapas varied during AGRs highest 1.17 ± 0.06 mm day−1 Bolinao, 1 0.08 days 60, respectively. lengths end study 46.7 0.15 58.8 2.4 mm, respectively, both high 96% Negative correlations observed between individual competitors, Our results highlight importance predator competitor management measures appropriate site selection optimize performance culture