<i>Isospora lacazei</i> (Labbe, 1893) and <i>I. chloridis</i> sp. n. (Protozoa: Eimeriidae) from the English Sparrow (<i>Passer domesticus</i>), Greenfinch (<i>Chloris chloris</i>) and Chaffinch (<i>Fringilla coelebs</i>)

Abstract

SYNOPSIS. Two species of Isospora are described from Chloris chloris with the additional hosts Passer domesticus and Fringilla coelebs. I. lacazei Labbé has spherical oocysts measuring 16.6 to 30.0 μ; the oocyst wall is colorless and smooth, consisting of a thick layer and, in the majority of oocysts, an inner thin membrane. Stages of the life cycle in the epithelial cells of the duodenum are described. The internal stages consist of first and late generation schizonts which produce merozoites without any residual body, spindle‐shaped microgametes and macrogametes without obvious “plastic granules.” The oocysts of I. chloridis sp. n. have colorless, smooth surfaced walls of one thick layer. They are ellipsoidal, measuring 17.2‐33.2 μ× 16.6‐30.0 μ. The internal stages of this species infect the epithelial cells of the small intestine in the same region as I. lacazei. They produce 2 generations of schizonts, consisting of merozoites and a residuum; microgametes are comma‐shaped and macrogametes have obvious “plastic granules.”