USO DE ÓLEO ESSENCIAL DE ERVA CIDREIRA, Lippia alba, COMO SUBSTÂNCIA SEDATIVA PARA JUVENIS DE ARRAIA CURURU, Potamotrygon wallacei

Abstract

This study used the essential oil of Lippia alba as a sedative to transport juvenile stingrays of the species Potamotrygon wallacei (cururu stingray), for a period of 24h. To establish the ideal concentration, increasing doses of 5, 10 and 15μL.L-1 of the substance were used in two experimental steps. In the first, the behavior of the exposed animals was evaluated, and in the next, the identification of possible physiological changes and gill morphology. For the assessment of behavior in each treatment, six individuals were individually opened open bags containing 1 L of water provided with constant aeration. At four-hour intervals (0, 4, 8, 12, 16 and 24h), the spirarular frequency, reflex activity and swimming capacity of each animal were evaluated. The concentration 5μL.L-1 did little to change the animals' activity, which was discarded for the 2nd stage. The other concentrations (10 and 15μL.L-1) promoted stages of light and deep sedation in individuals, respectively, with the 15μL.L-1 causing death in the last four hours of the experiment. In the second stage, hematological parameters, plasma metabolites and possible changes in the histology of the gills were evaluated after 24h of exposure. The hematological parameters at both concentrations did not differ from the pre-exposure group, as did the plasma metabolites, with the exception of lactate, which was significantly lower at the concentration of 15μL.L-1. In histology, the changes observed were similar in both concentrations tested, which are reversible, with identification of mild hyperplasia and hypertrophy of epithelial cells and chloride. In addition, there was no death at this stage. Thus, due to the absence of mortality, in addition to the sedative potential and the absence of irreversible lesions in the animals' gill apparatus, the concentration of 10μL.L-1 proved to be the most suitable for the transport of individuals from the stingray for periods of 24h. Keywords: Stress. Lippia alba. Potamotrygon wallacei. Protocol. Transport