Immersion of rohu fingerlings in clove oil reduced handling and confinement stress and mortality

Abstract

The use of anaesthetics becomes essential in the transportation medium for mitigating physiological stress and reducing metabolic rates. Clove oil is now emerging as safe, eco-friendly, effective, and economic fish anaesthetic. We tested the efficacy of clove oil as an anaesthetic for the handling and transportation of rohu, Labeo rohita (Hamilton-Buchnan) fingerlings. The lowest effective dose of clove oil that produced induction (≤3 min) and recovery (≤5 min) found was 50µl L -1 .The induction times decreased and recovery times increased with increased in the concentrations of clove oil. The effective sedative dose at 5µl L -1 of clove oil was found suitable for transportation in plastic bags with pure oxygen up to 12h. The mortality rate (%) of fingerlings was significantly higher (14.4±1.14%) in the control (without sedative) than sedative doses of clove oil (P<0.05). The dose at 5µl L -1 of clove oil was found to mitigate stress responses with lower glucose level and reduce the deterioration of water quality in comparison to control. The present findings revealed that clove oil is promising to be used as anaesthetic and sedative for handling and transportation of rohu fingerlings. Clove oil is feasible to use in the commercial fish seed transportation due its merits like cheap and safe anaesthetic.