Estudo de uma série de tanques de alvenaria como modelo para condução de experimentos com organismos aquáticos

Abstract

Water quality determines lhe success or failure of fish researches. A series of rectangular concrete tanlcs covered with nylon nets were evaluated as a pattem for conduction assay with aquatic animais, when environment conditions must be the sarne. Physical and chemical characteristics ofwater were observed. The tanlcs were populated with ten juvenile pacu (Piaractus mesopotamicus) which were fed ad /ibitum twice a day. The experiment was carried out between November and February of 1992/1993. ln the middle of experiment five fishes were slaughtered in order to keep the biomass adequate until the end (87 days). Insuitable limnologic conditions were detected in the lower waterflow tanlcs. Toe increased biomass and decreased waterflow were related to increased mortality and diseases. This kind of serial tanlcs building allows homogeneous environmental conditions and the waterflow was the parameter which must be carefully monitored.