USE OF HOT BRANDING IN MARKING JUVENILE PIKEPERCH (STIZOSTEDION-LUCIOPERCA)

Hot branding methods used for adult fish are generally considered harm ful to juveniles. Use of a very thin electrically heated metal (nichro me) wire to impress a mark on the scales of the fish is a fairly gentl e procedure compared with the traditional method of branding. The thin metal filament can easily be shaped to form code symbols. About 200 0 00 one-summer-old pikeperch (Stizostedion lucioperca) juveniles (mean weight 2.5-5.5 g) were branded with this method during 1986-1995 and s tocked in two lakes in southern Finland. No mortality or physiological responses caused by the branding were observed and the marks were rea dily identified on adult fish several years after application. This me thod is very economical. Branding instruments cost about FIM 600 and o ne person can mark up to 500-1 000 fish per hour. The method is suitab le for pikeperch and other species with fairly small and firmly attach ed scales.