MITOCHONDRIAL-DNA VARIATION IN LAKE STURGEON (ACIPENSER-FULVESCENS) FROM THE ST-LAWRENCE-RIVER AND JAMES BAY DRAINAGE BASINS IN QUEBEC, CANADA

Restriction fragment length pattern analysis of mitochondrial DNA (mtDNA) was used to assess genetic differentiation in sympatric lake sturgeon (Acipenser fulvescens) from the St. Lawrence River drainage basin (St. Lawrence and Ottawa rivers and Lac des Deux Montagnes) and in sturgeon from the Waswanipi River (James Bay drainage basin). Using 14 restriction enzymes on mtDNA from 82 specimens, the genetic divergence was relatively low (d = 0.219-0.744%), as only three genotypes were found. Genotype 1 is present at all sites whereas genotype 2 is present only in Lac des Deux Montagnes and the Ottawa and Waswanipi rivers. The St. Lawrence River sturgeon form a homogeneous genotypic group that was not found significantly different from sturgeon from Lac des Deux Montagnes. The genetic heterogeneity seemed higher in the James Bay drainage population than in the St. Lawrence drainage populations that probably have been more significantly influenced by over-fishing and man-made habitat changes.