Anesthesia in pirarucu by eugenol sprays in the gills

Abstract

Pirarucu (Arapaima gigas) is an important species to commercial fish farming in Amazon. It achieves more than 2m and 100kg. However, fish handling may be risky to workers. Anesthesia is necessary, but usual anesthetic baths are not feasible due to the size of fish and the pulmonary respiration of Pirarucu. This fish may die drowned in anesthetic baths. This research evaluated the alternative anesthetic eugenol to pirarucu by sprays in the gills. Solution in concentration of 30mg L-1 was sprinkled in the gills of three fish, and 60mg L-1 was sprinkled in the gills of two other fish. Eugenol sprays provided safe anesthesia for pirarucu. No mortality was observed even one month after the experiment.