Mallasen, M., W. C. Valenti
Differences in culture duration, the metamorphosis rate and the productivity in the hatchery of M. rosenbergii using a closed system with natural and a specific artificial brackish water were evaluated. Information regarding the reuse of brackish water in more than one hatchery cycle was also obtained. Natural brackish water and artificial brackish water constituted the two tested treatments, which were distributed in four recirculating systems (tank and respective biofilter). Four batches of culture were made in which the 2nd and 4th reused the water from the 1st and 3rd, respectively. The results obtained show that the mean duration of hatchery period was 28 days in natural brackish water and 31 days in artificial brackish water. The metamorphosis rate and the average productivity obtained in the natural brackish water treatment was 74% and 60 postlarvae/L, respectively, higher than the values obtained in the hatchery with artificial brackish water, which were 55% and 44 postlarvae/L. However, the results show the viability of hatchery of M. rosenbergii in this specific artificial brackish water and its use can be advantageous in enterprises located far from the coast. Brackish water can be used in two consecutive cultures without negatively influencing productivity.
(Faculdade de Ciencias Agraria e Veterinarias, Centro de Aquicultura da UNESP, NEBECC 14870-000 Jaboticabal, SP, Brazil)
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