Summary of investigations on the morphometry of the cisco, Leucichthys artedi (Le Sueur), in the lakes of the northeastern highlands, Wisconsin

Abstract

The morphometric studies on the cisco or lake herring, Leucichthys artedi (Le Sueur), which are briefly summarized in this paper are part of a program of investigation of the fishes of the lakes in the northeastern highland district, Wisconsin. For the morphometric studies, 1,548 specimens were employed, all of them collected in the summers of 1931 and 1932 from four 'type' lakes, selected on the basis of their size, depth, and physicochemical and biological characteristics. Of this number 753 individuals were used to determine the general nature of the morphological variations in the Trout Lake, Muskellunge Lake, Silver Lake, and Clear Lakes cisco populations, while 795, collected from Muskellunge Lake in 1932 were employed in a detailed examination of certain morphological differences between the 1928 and 1929 year classes of that population. An attempt is made in this paper to present all the important conculsions, together with a small amount of illustrative material.