Assembling the superior biofloc tilapia strains for industry

The decreasing productivity and increasing environmental pressure on intensive tilapia culture in open waters, especially in floating net cages, have forced the development of a biofloc system for tilapia farming. This study aimed to develop the superior tilapia strain suitable for the biofloc system and to observe their productivity and economic profitability under commercial scale in the biofloc system. The selective breeding activity was carried out on 100 families reared and mated in hapa (a double-walled contrivance in which an inner hapa, made of mosquito netting material, is installed within an outer one made of whole cloth) in the biofloc pond for three generations. The individual selection was conducted at the age of 6 months on the characters of standard length and body weight with the best 10% of the top part of the population as a reference for the formation of the next generation. After three generations, the offspring obtained from mass spawning were grown out in round-limen ponds and square-concrete ponds for productivity and profitability observations. The results showed that heritability values of the biofloc tilapia strain were 0.4196 (standard length, SL) and 0.4898 (body weight, BW). The average response selection of BW and SL was 13.04% and 6.11%, respectively. Biomass gain was obtained between 19.29–28.83 kg/m3. The production multiply value was 8.07-13.59x. The average daily weight growth was between 2.8g-3.0g. The Benefit-Cost ratio is valued from 1.81 to 2.71. The superior tilapia biofloc strain has a moderate heritability value. When it is raised in a biofloc ponds system at different volumes, it significantly affects the productivity on biomass, body weight, and multiplication value. Also, it is advantageous when applied on an industrial scale.