POLYMERASE CHAIN REACTION-BASED SPECIES IDENTIFICATION OF SALMON AND COASTAL TROUT IN BRITISH-COLUMBIA

The western coast of North America has seven native species of anadrom ous salmon and trout (Oncorhynchus spp.), introduced brown trout (Salm o trutta), and low numbers of Atlantic salmon (S. salar) that have pre sumably escaped from fish farms. Species identification based on morph ology of intact juvenile or adult specimens is not usually difficult, but in cases in which only anonymous tissue samples, larvae, or suspec ted hybrids are examined, molecular methods of identification are ofte n required. Current molecular species identification techniques involv e electrophoresis of proteins and restriction mapping or sequence anal ysis of mitochondrial or genomic DNA. Here, the development of a new, DNA-based species identification method using the polymerase chain rea ction (PCR) to amplify a portion of the growth hormone type-2 gene is described. No intraspecific variation was detected when this species i dentification method for Oncorhynchus and Salmo species was tested on representatives of 31 different populations collected from 19 location s on the western coast of North America. The test was also applied to anonymous samples, interspecific hybrids, and suspected feral Atlantic salmon larvae, as well as to commercially prepared fresh, previously frozen, and smoked fish samples.