Production of live food for initial feeding of freshwater fish larvae

Abstract

In order to produce live food needed for the initial feeding of freshwater fish larvae, the microalgae Chlorella homosphaera and the euryhaline rotifer Brachionus plicatilis were mass cultured: the former, in 60 Iiters fiberglass containers filled with freshwater and commercial fertilizers, and the latter, in until 500 liters tank in a semi continuous system. Salinity was maintained at about 18% by adding NaCI to fresh water. The rotifers were fed with fresh baker's yeast Saccharomyces cerevisiae. The maximum production of microalgae was between the 4^th and 6^th days, and the concentration reached 5 x 10⁶ cell.mL^-1. The maximal density reached 650 organisms.mL^-1, and the rotifers populations in the mass cuIture were maintained at relatively high density of 100 -150 organisms.mL^-1, for a period of about 50 days. The periodical harvests, that reached 39% of the total volume of the culture, represented about 6 to 8 million of rotifers.day^-1. The systems and methods utilized were efficient for the production of a great number of these organisms for the larviculture of "curimbatá" Prochilodus scrofa at the Laboratory of Freshwater Fish Biology, at Pirassununga, SP. These systems may be also applied for larva of other freshwater fish species.