Concentrações de amônia, nitrito e nitrato em larvicultura do camarão Macrobrachium rosenbergii (De Man), realizada em sistema fechado com água salobra natural e artificial

Variations of ammonia, nitrite and nitrate in a recirculating M. rosenbergii (Crustacea, Decapoda) hatchery, reusing natural and artificial brackish water, in two successive cultures, were studied. Ammonia and nitrite values oscillated between 1.1 to 74.0 µg/l and 1.1 to 34.6 µg/l, respectively, and did not differ among the tested water types. Nitrate concentrations (N) increased similarly with time (T), according to a linear model (N = 0,241T – 0,734) with both natural and artificial water. Data suggested that the use and reuse of the artificial water did not affect the nitrification process. Therefore, it can be used in recirculating systems for M. rosenbergii hatchery.