Anaesthetic efficacy of clove oil-coated LDPE bag on improving water quality and survival in the Siamese fighting fish, Betta splendens, during transportation

Abstract

With brilliant colouration and long, flowing fins, the Siamese fighting fish (Betta splendens) is one of the most popular species of freshwater aquarium fish. In the ornamental Siamese fighting fish business, stress is one of the major causes of fish injury, including collapse of the fins. To overcome this problem, attempts are being made to develop anaesthetic packaging, in which anaesthetic agents are coated onto low-density polyethylene (LDPE) packaging bags and released from the bags. The feasibility of using clove oil-incorporated methylcellulose-coated LDPE bag as a packaging material to induce an anaesthetic effect on Siamese fighting fish during transportation was also investigated. Based on a criterion of fish transportation within 2 days, concentrations of clove oil in anaesthetic-coated LDPE bag ranging from 0 to 11.67 mg L−1 were determined using an aqueous dilution method. Clove oil-incorporated methylcellulose-coated LDPE bags, filled with either 150 or 75 mL water and with equivalent anaesthetic concentrations, induced an anaesthetic effect in a similar manner. After 48 h of fish exposure, the water quality in clove oil-incorporated methylcellulose-coated LDPE bags was better than that of the control treatment. This study demonstrated that clove oil-incorporated methylcellulose-coated LDPE packaging bag could be successfully employed for transportation of Siamese fighting fish; in turn, this will minimize a dropped price when reaching the destination.