Biochemical identification of shark fins and fillets from the coastal fisheries in New Zealand

The protein fingerprints of shark fillets and fins taken from commercial la ndings in northern New Zealand waters were compared with the protein finger prints from control samples of ten species of coastal sharks. Isoelectric f ocusing (IEF) in agarose gels revealed species-specific protein profiles in the ten control species. The fillets and fins were identified as school sh ark (Galeorhinus galeus), rig (Mustelus lenticulatus), hammer-head shark (S phyrna zygaena), and bronze whaler (Carcharhinus brachyurus). Around 40% of fillets from cartons labelled as lemon fish (M, lenticulatus) were from ot her species. Shark fins were identified from four species, two of which are prohibited target species in northern New Zealand. The large number of mis labelled shark products necessitates the use of a simple biochemical techni que for identification of shark species in commercial shark products. With IEF, around 100 specimens can be identified by a laboratory technician each working day from small amounts (<0.5 g) of white muscle.