POSITIVE EFFECTS OF BIOFLOC SYSTEMS ON NILE TILAPIA OFFSPRING PRODUCTION

Julie Ekasari*, Enang Harris Surawidjaja, Muhammad Zairin Jr., Peter De Schryver, Peter Bossier
 
Departement of Aquaculture
Faculty of Fisheries and Marine Science
Bogor Agricultural University
Indonesia
j_ekasari@ipb.ac.id

Tilapia is one of the most important aquaculture species that has been intensively produced all over the world. The production, however, could be limited by the availability of good quality seed. The present study investigated the application of biofloc systems in Nile tilapia broodstock and larvae culture with more focus given on the reproductive performance of the broodfish and the production performance as well as the robustness of the larvae. On the first experiment, Nile tilapia broodstock were housed in two different environments, biofloc environment (with organic carbon addition) and control environment (without organic carbon addition) for 84 days of experimental period. Tilapia maintained in biofloc system showed generally higher fecundity than that of the fish in control system. The total larvae produced by the broodstock housed in biofloc system was 65% higher that housed in the control system.  The second experiment elucidated the effect of housing the broodstock and the larvae in biofloc system on the larvae production and robustness. Tilapia broodstock was maintained with the same manner as the first experiment. A growth test was performed with larvae that were harvested from each broodstock treatment tank and were subsequently housed in a biofloc environment or a control environment. After the growth test, the survival of the larvae from biofloc broodstock was significantly higher than the survival of the larvae from control broodstock, indicating the enhanced robustness of the larvae produced by biofloc broodstock (Table 1). This was confirmed by the results of salinity stress test and challenge infection with the pathogenic Streptococcus agalactiae, which showed that the survivals of larvae from biofloc broodstock were significantly higher than the larvae from control broodstock. Furthermore, the resistance against S. agalactiae of the larvae originating from control broodstock were also enhanced when they were maintained in biofloc water.