Efeito do óleo essencial de Lippia alba (Mill.) N. E. Brown, no transporte simulado de alevinos de Tambaqui (Collossoma Macropomum) na Região Oeste do Pará.

Abstract

The aim of the study was to evaluate the potential of the essential oil of Lippia alba as an additive in the simulated transport of tambaqui fingerlings ( Colosoma macropomum ) , noting the survival and behavior of physical-chemical parameters of the water . The simulated transport was performed for 17h in closed system ( plastic bags ). Two essential oil concentrations were used: 5 and 20 μL.L - ¹ and three control treatments were evaluated : Pure water ( Cágua ) ; water + alcohol ( CAg + Al ) and terramycin + salt ( CT + sal) . The stocking density used was 105 peixes.L - 1 or 117.6 gL - 1 and each treatment had 3 replicates . Physico-chemical parameters (pH , temperature , conductivity and dissolved oxygen) were measured with the aid of multiparameter probe . Survival was calculated counting the total number of live and dead fishes after 30min of acclimation in tap water. Survival in all treatments were satisfactory , with the highest values found in LA [ 20 ] treatment and CT + sal ( 99.06 % and 99.34 % respectively). The lowest survival rate was found in the LA[ 05 ] treatment ( 90.14 % ) . In relation to oxygen , treatment CT + sal showed the worst results ( 1:21 ± 0.63 mg.l-1 ) . The treatments with essential oil obtained satisfactory results of dissolved oxygen. In the LA [05] treatment the obtained value was 4.03 ± 0.31mg.L- 1 and LA [20] was 3:01 ± 0.44mg.l- 1 . The pH values were within the comfort range for the species in all treatments . The use of the essential oil of L. alba in the concentration of 20 - μL.L -¹ is effective in the transport of tambaqui fish fry , resulting in high rates of survival and maintenance of dissolved oxygen levels .