A survey of the Entomostraca of Manitoba and a study of feeding of Lake Winnipeg ciscoes

Abstract

The scientific value of a survey of the Entomostraca of Manitoba was first suggested to the author as a worthy undertaking, and as a suitable subject for a Ph. D. thesis, by Dr. J. A. McLeod under whose direction this work was begun over five years ago. The years intervening have been spent in the examination of samples of plankton collected from nearly 80 lakes from various parts of Manitoba. Samples from over 100 ponds, ditches and sloughs, and from 20 rivers and creeks have also been studied. Collections from so many sources and from such an extensive area could never have been made by one worker and the assembling of all these collections for study by the author represents an example of scientific teamwork which should be heartening to all scientific workers and reflects great credit on the agencies involved. The chief agencies for collection of plankton samples were: The Game and Fisheries Branch, Department of Mines and Natural Resources, Province of Manitoba; and the Central Fisheries Research Station, Fisheries Research Board of Canada, Winnipeg, Manitoba. During the years 1941-1947, plankton samples were collected for the Game and Fisheries Branch, Province of Manitoba, by Dr. J. A. McLeod and/or D.R. Moir, and subsequently by other field parties under the direction of G. E. Butler. Collections made included dredge samples, vertical lifts, horizontal drags usually at the surface and at 12-15 feet, and littoral collections along the shore and among water plants. Collections made by these agencies were supplemented by extensive collections made by the present worker. The importance of a survey of the Entomostraca of Manitoba (Parts I, II and III of this thesis) may be dealt with under three headings: (1) Entomostraca as links in food chains and especially as food of fishes. (2) Entomostraca as intermediate hosts of parasitic organisms. (3) The value of a survey of the Entomostraca of Manitoba as a contribution to general scientific knowledge...