Comparative Efficacy of Anesthetic Agents (Clove Oil and Sodium Bicarbonate) on Cultured African Catfish, Clarias gariepinus (Burchell, 1822) and Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758)

Abstract

Fish (Fin and shellfishes) is a principal supply for humans, especially as source of animal protein 7,8 ; digestible minerals 9, 10 ; commercial (profit-making) or subsistence (survival) farming 11 and also serve as important by-products for exportation in many regions of the world. 12 . Anesthetics are chemical/physical agents used to calm animals by causing them to gradually lose their equilibrium, mobility, consciousness, and ultimately their reflex action 13 . In laboratories, overdose of anaesthesia is often usually use as euthanasia at the end of experimental procedures and it is not a common practice for fish which is destined for the food chain. 14 Availability of an anesthetic that is nontoxic, inexpensive, easily administered and able to immobilize fish quickly with good recovery rate make it an ideal candidate for anesthesia 15,16 . Tricaine methane sulphonate (MS-222), benzocaine (ethyl-p-aminobenzoate), ethylen glycol monophenyl ether (eugenol and 2-phenoxyethanol), methomidate and clove oil are the most commonly used anesthetics in aquaculture. 17 There are many factors influencing the efficacy of anesthetic agent in fishes. These are biological factors, environmental factors; fish species, fish body size, the fish density in the bath solution and the water quality parameters 18,19,20,21 . Different species differ greatly in their responses to various anesthetics. 22,23,24 It is therefore very vital to screen and select the best anesthetic and effective doses for a particular species and procedure. This is because unpremeditated adverse effects can result from a good anaesthetic if not