SYSTEMATICS OF THE SALMONID GENUS SALVELINUS INFERRED FROM RIBOSOMAL DNA-SEQUENCES

DNA sequences of the second internal transcribed spacer (ITS2) of the nuclear ribosomal DNA were determined for six species of the genus Sal velinus: S. alpinus (Arctic char), S. malma (Dolly Varden), S. conflue ntus (bull trout), S. leucomaenis (Japanese char), S. fontinalis (broo k trout), and S. namaycush (lake trout), and for Hucho perryi (huchen) . The ITS2 sequence data (approximately 375 base pairs (bp)) were comb ined with previously determined sequence data for the ITS1 (approximat ely 575 bp), giving a total of 981 bp of aligned sequence for each spe cies. Phylogenetic analysis of the aligned sequences was done using ma ximum parsimony, maximum likelihood, and distance matrix methods with H. perryi as an outgroup. The results were consistent with previous wo rk based on comparisons of morphologies, allozymes, and karyotypes. Co mparison of these results with those based on mitochondrial DNA sequen ces suggests that hybridization may have occurred between S. confluent us and S. alpinus or S. malma.