O efeito da relação água:oxigênio, da densidade e da duração do tempo de transporte em sistema fechado sobre a mortalidade de juvenis de tambaqui (Colossoma macropomum)

Abstract

Juveniles mortality of tambaqui at the end and after transportation can cause damages to producer and consequently compromising the productivity of the culture. Thus, the present study had the objective to test the water:oxygen ratio, density and duration of transport of tambaqui closed system. In the first experiment, the juveniles were transported for 6 hours with densities of 67, 50, 40 and 33 fish/L, which tested different proportions of water:oxygen ratio in the transportation bags , namely, 1:3 , 1:2 , 1:1.4 and 1:1. In the second experiment, the juveniles were transported for 6 hours at a proportion 1:3 of the water:oxygen ratio, which tested the densities of 67, 87, 107 and 133 fish/L. In the third experiment, the juveniles were transported at a proportion 1:3 of water:oxygen ratio and density of 133 fish/L, which were tested the time of 6h , 12h , 18h and 24h of transportation. In all experiments, mortality was evaluated at the end (opening the bags) and after transportation, in floating cages, during intervals of 6h, 12h, 18h, 24h and 30h, as well as the quality of water. The ratio water:oxygen, density and time of transportation had no significant relation with mortality at the end and until to 30 hours after transportation. The condition biotic and/or abiotic of ponds was a limiting factor for mortality of tambaqui after transportation. The water quality parameters remained within acceptable limits for the maintenance and development of the specie at the end and until to 30 hours after transportation. So that the ratio water:oxygen, density and time of transportation did not influence the mortality of tambaqui at the end and until to 30 hours after transportation, but the condition of the ponds, where fish were kept after transportation, yes.