Elevated Salinity Tolerance of Reciprocal Hybrids of Improved Brackishwater Enhanced Selected Tilapia (iBEST) Oreochromis spp.

This study evaluated the salinity tolerance of juvenile reciprocal hybrids of saline-tolerant tilapia strain in terms of salinity indices: Median Lethal Salinity (MLS), Mean Salinity Tolerance (MST), and Optimum Salinity Tolerance (OST). After the 25-day challenge of progressive salinity increase by 3 ppt, it was observed that the progenies of the two reciprocal crosses of iBEST showed no significant differences in terms of MLS (iBEST Hybrid 1=62.67±3.21 ppt; iBEST Hybrid 2=54.00±5.29 ppt), MST (iBEST Hybrid 1=54.33±3.06 ppt; iBEST Hybrid 2=56.33±4.73 ppt), and OST (iBEST Hybrid 1=36.00±2.65 ppt; iBEST Hybrid 2=37.67±6.03 ppt) values, indicating that the offspring of the reciprocal crosses of parents is lacking of maternal/paternal influence with regards to the salinity tolerance of its progenies. Therefore, reciprocal hybrids of the iBEST Parent Lines would have a comparable salinity tolerance during the grow-out culture of tilapia in a brackish and saline environment. Salinity tolerance values of iBEST are significantly higher compared to the MLS (31.33 ± 6.43 ppt), MST (35.67 ± 2.52 ppt), and OST (14.33 ± 2.52 ppt) values of iEXCEL (Oreochromis niloticus) juveniles. This study demonstrated the capacity of iBEST hybrids in terms of salinity tolerance and its potential in brackish and saline water aquaculture.