Decapitation and brining: experimental tests show that after these commercial methods for slaughtering eel Anguilla anguilla (L.), death is not instantaneous

Abstract

The recent idea that fish, like all vertebrates, have emotional brains is based on new evidence about the evolution of the brains of vertebrates, and about homologies between behavioural, neurohormonal and neurostructural features of fish and mammals (humans). Therefore it is now assumed that fish are liable to suffer, and should be slaughtered by methods that induce insensibility by the fastest way, as is required for mammals. Two commercial methods for slaughtering eel, decapitation and brining, were experimentally tested and found inadequate: severed eel heads showed signs of life for up to 8 h; after the brining procedure eels remained alive for up to 18 h. It has been too readily assumed that, like a mammal, a fish is killed immediately by decapitation. The so-called isolated gill preparation, a standard method for studying various gill functions, but actually involving part of a severed fish head, is one further example of this shallow generalization.