Eugenol as anesthetic for fingerlings of patinga (Piaractus mesopotamicus x Piaractus brachypomus)

Abstract

RESUMO:O objetivo com a realização deste trabalho foi avaliar o eugenol como agente anestésico para o hibrido patinga. Foram utilizados 60 alevinos com peso médio de 1,08 ± 0,17 g e comprimento total médio de 3,53 ± 0,15 cm. Avaliaram-se seis concentrações diferentes de eugenol (10, 20, 30, 40, 50, 60 mg L -1 ). Os peixes foram expostos individualmente ao anestésico para avaliação da indução anestésica, após o procedimento de anestesia, os peixes foram transferidos para aquários com água livre de anestésico, para observação do tempo de recuperação. Posteriormente, os peixes de cada tratamento foram colocados em aquários com capacidade de 30 litros para o monitoramento da mortalidade, durante 72 horas. Observou-se diferença significativa (P<0,05) para os tempos de indução e recuperação anestésica para as diferentes concentrações de eugenol. Observou-se mortalidade de animais em concentrações acima de 40 mg L -1 de eugenol. Conclui-se que a melhor concentração eugenol para a anestesia de patinga é de 20 mg L -1 , pois apresentou eficiência na indução e recuperação de anestesia, sem causar mortalidade.Termos para indexação: Anestesia, híbrido, nativos, aquicultura. ABSTRACT:The aim of this work was to evaluate eugenol as an anesthetic agent for hybrid patinga. Were used 60 fingerlings with an average weight of 1.08 ± 0.17 g and total length of 3.53 ± 0.15 cm. They were evaluated six different concentrations of eugenol (10, 20, 30, 40, 50, 60 mg L -1 ). The fish were individually exposed to anesthetic to evaluate the anesthetic induction, after the anesthesia procedure, the fish were transferred to aquaria with anesthetic free water, for observation of recovery time. Thereafter, the fish in each treatment were placed in tanks with 30 liters for monitoring the mortality during 72 hours. There was a significant difference (P <0.05) for the induction times and recovery room for different concentrations of eugenol. Mortality was observed in animals above 40 mg L -1 eugenol concentrations. It is concluded that the best concentration for the eugenol anesthesia patinga is 20 mg L -1 showed efficacy for the induction and recovery of anesthesia, without causing mortality.

Current knowledge on use of essential oils as alternative treatment against fish parasites

“…A study on Piaractus mesopotamicus reported that almost 50% of the fish did not survive exposure to Melaleuca alternifolia (Valladão et al, 2016). In addition, mortality among Brycon hilarii exposed to eugenol at 250 mg L À1 (Fabiani et al, 2013), hybrid P. mesopotamicus x Piaractus brachypomus exposed to 50 mg L À1 (Rodrigues et al, 2015), Centropomus undecimalis exposed to 75 mg L À1 (Bernardes-J unior et al, 2013) and Cyprinus carpio exposed to 0.08 mg L À1 (Kamble et al, 2014) has been reported. Several studies on EOs have also used biochemical, hematological and histopathological parameters to evaluate signs of toxicity in the oil tested (Hashimoto et al, 2016;Soares et al, 2016;Soares et al, 2017a, b).…”