Use of Variation in Biological Characters for the Classification of Anadromous Rainbow Smelt (Osmerus mordax) Groups

Abstract

Analysis of meristics, growth patterns, and fecundity to somatic weight relationships of spawning anadromous rainbow smelt (Osmerus mordax) in Quebec waters demonstrated the existence of three geographical groups (Chaleur Bay, south shore of the St. Lawrence Estuary, and Saguenay Fjord). Although homing to spawning rivers does not appear to occur, the degree of heterogeneity of spawning smelt of different geographical areas is less at the extremes of their Quebec distribution. Classification of smelt from the commercial fishery catch indicates limited mixing of these groups during open-water migration. The existence of a fourth group is suggested by classification analysis of smelt caught along the lower north shore of the St. Lawrence Estuary.