The production of Brachionus plicatilis rotifers is essential for the development of marine fish larviculture, since it is commonly used as the first food for larvae. The use of the microalga as food enables good quality of rotifers large-scale production. Thus, new species of microalgae have been tested due to their nutrient profiles, mainly lipids, minerals and pigments.
The first experiment was conducted to evaluate N. oceanica on rotifers production. The trial was delineated from the factorial statistical model of Central Composite Rotatable Design. The rotifers were stocked at different densities (59, 100, 200, 300 and 341 rot mL-1) and fed with different amounts of concentrated N. oceanica (59, 100, 200, 300 and 341 × 109 cell rot-1 day-1).
The second experiment evaluated three concentrations (2,5, 5 and 10 × 109 cell/ 1 × 106 rot-1 day-1) of P. cruentrum as food for rotifers, plus two controls treatments fed with 200 × 109 cell 106 rot-1 day-1 of N. oceanica, and 0,7 g of baker yeast 106 rot-1 day-1.
After the experiment 1, a surface response graph (Figure 1) was generated for the results of population growth rate. While the results of rotifer population growth in rotifers fed with P. cruentrum are shown in the Figure 2.
In conclusion, in order to obtain a maximized population growth rate of the rotifer B. plicatilis, it is recommended to use a N. oceanica concentration of 300 × 10? cell 106 rot-1 day-1 and a rotifer stocking density of 100 rot mL-1. The concentration of P. cruentrum must be kept at 10 × 109 cell/ 106 rot-1 day-1.