Abstracts Biological Sciences

The life history and ecology of the northern lake chub (Couesius plumbeus) in the La Ronge region of Saskatchewan

by Joseph Harry Brown

Very little has been published pertaining to the life history and ecology of the lake chub (Couesius plumbeus (Agassiz), at present equal to Hybopsis plumbea (Agassiz)), and the purpose of the this study was to gain some knowledge in these areas. References to C. plumbeus are common in the literature but they mostly comprise incidental remarks. Life history studies are confined to an unpublished B.A. thesis undertaken in some small British Columbia lakes by Geen (1955). Data on the life history of Couesius in Michigan are being collected by Dr. V. C. Applegate. The problem of defining Couesius subspecies and the direct involvement of C. plumbeus in the present controversy over the validity of the genus Hybopsis made this project more interesting. Before these problems can be satisfactorily resolved, it is necessary that the variation of taxonomic and behavioral characteristics of the species be clearly established throughout the geographical range. Studies such as the present one help provide such information.