Nematopsis ostrearum and N. prytherchi (Eugregarinina: Porosporidae) with Special Reference to the Host-Parasite Relations

Abstract

of host-parasite relation, the opportunity was taken to test the opinion formed by the senior author in preliminary observations that the two types of spores mentioned by Prytherch (1940) represent two species. The senior author, at the same time, extended the observations made by Prytherch (1938, 1940) on morphology and life cycle. Nematopsis ostrearum Prytherch has already been separated into N. ostrearuml, emended, and a new species, N. prytherchi, by Sprague (1949) in an abstract anticipating a series of papers dealing with these species. In this paper experiments are reported which concern primarily the host-parasite relations, but which also provide part of the basis on which the two species of Nematopsis were separated. A later paper will deal more fully with morphology and life cycle of the parasites. During June, 1948, through January, 1949, three infection experiments were performed at Louisiana State University Marine Laboratory, Grand Isle, La., to obtain, in addition to other data, information on host-parasite relations. These