Host Resistance and Regulation of the Development of Plasmodium lophurae in Pheasants, Coots and Domestic Pigeons

Abstract

To know the nature of a parasite one must study it under all conditions compatible with its development. Plasmodia are related to their hosts in a highly specialized manner, and their mode of reproduction enables one to study quantitatively certain fundamental aspects of their behavior in all possible host-parasite combinations. This problem of biological inter-relations was undertaken to determine the effects of various hosts upon the course of development of P. lophurae as reflected by: (1) the rate of reproduction; (2) the course and intensity of parasitemia; (3) the destruction and survival of parasites; and (4) the percentage frequency of merozoite groups. Plasmodium lophurae (Coggeshall, 1938) is capable of reproducing in diverse avian hosts. Indeed, its hosts have lately been extended to include mice (McGhee, 1951). This indicates an unusual adaptability of the schizogonous cycle; therefore it is not surprising that it displays little avian host specificity. Considerable work has been done on various aspects of the biology and morphology of P. lophutrae but detailed studies of the asexual cycle have been carried out using ducks and chickens as hosts.