Reduced dorsal spine numbers in two isolated populations of the brook stickleback ( Culaea inconstans) from eastern Canada.

The sample from Lac du Beau Portage, Quebec, is made up entirely of fishes with 1 or 2 dorsal spines. The Ontario sample, from Tom Lake, has 2-5 spines, and the Tom Lake pelvic skeletons varied from complete to absent. -from Authors