Effect of Color During Transport and Anesthetic Efficacy of Alcoholic Drink, 2-Phenoxyethanol, Clove Oil, MS-222, and Benzocaine in Silver Therapon, Leiopotherapon plumbeus (Kner 1864)

The study evaluated the survivability of silver therapon, Leiopotherapon plumbeus (Kner, 1864) in different color containers during transport and the efficacy of five anesthetic agents [alcoholic drink, 2-phenoxyethanol, clove oil, tricaine methanesulfonate (MS-222), and benzocaine] in the induction and recovery time of L. plumbeus. Different colored polyethylene bags (black, red, yellow, blue, and transparent) did not influence the survival rate of fish until the termination of the experiment (12-h transport time). The immersion experiment used three different concentrations in each anesthetic agent with three replicates (ten fish specimens per replicate). Different dosages significantly influenced the induction time, with decreased induction efficacies in high dosages. Moreover, the 200 ml L-1 and 300 ml L-1 alcoholic drinks anesthetized the fish specimens comparable to the induction efficacy of several dosages of 2-phenoxyethanol, MS-222, and benzocaine. Recovery time significantly varied among treatments, with a prolonged recovery period with increasing anesthetic concentrations. Regression analysis revealed a positive correlation between fish standard length and induction time (P < 0.05), albeit more pronounced in smaller dosages. Induction and recovery times were not correlated to fish size when exposed to higher dosages. The present finding demonstrated the anesthetic efficacy of four commercial anesthetic solutions, so as with alcoholic drinks with concentrations between or equal to 200 ml L-1 and 300 ml L-1. Experimental trials for fish euthanization and field trials are open for further investigation.