(Rapid colbranding with liquid nitrogen for rainbow trout (Salmo irideus, Gibbons) identification)

Abstract

With the objective of testing the efficiency of a method to mark fishes, an experiment was carried out at the Estação Experimental de Salmonicultura de Campos do Jordão. Three hundred rainbow trouts (Salmo irideus, Gibbons) were submitted to the method of cold branding in the region between the dorsal finn and the operculum, with frozen copper numbers imersed in liquid nitrogen (-196°C). The method was practically inocuous, rapid, and easy to be applied and the identification was possible in 77.90% of the specimens after three months. This time can be considered good enough for the realization of various experiments with salmonids.