Role of biofloc technology in hatchery efficiency for farming of mangrove crab (Scylla serrata)

Abstract

Mangrove crab aquaculture is expanding in response to the growing global demand, however, production in the Philippines remains limited due to low survival rates, which are attributed to suboptimal water quality, insufficient nutrition, and disease outbreaks. This study assessed the overall performance of <i>Scylla serrata</i> from zoea to crab instar in various culture media: Biofloc water (BW), green water (GW), and clear water (CW). Survival from zoea 5 to crab instar was highest in GW; however, no significant differences were observed among treatments (<i>p</i>&gt;0.05). Microbial analysis showed significantly higher total heterotrophic bacteria and presumptive <em>Vibrio</em> counts, but significantly lower luminous bacteria, in BW compared with GW and CW (<i>p</i>&lt;0.05). Crabs reared in BW exhibited significantly higher survival after 12 hours of simulated transport and greater tolerance to abrupt low salinity exposure after 12 and 24 hours (<i>p</i>&lt;0.05). Although survival after 24 hours of transport did not differ significantly among treatments, BW consistently maintained the highest mean survival. Overall, BW emerges as a promising alternative culture medium to traditional hatchery protocols, particularly during early larval stages (zoea 1–5). This study provides the first empirical evidence supporting the use of biofloc technology in mangrove crab larval hatchery systems, with the potential to enhance both resilience and sustainability.