The life cycle of Cloacitrema michiganensis McIntosh, 1938 (Trematoda: Philophthalmidae).

Experimental infections of Cloacitrema michiganensis were established in chicks by inoculation per cloaca with excysted metacercariae. Ovigerous adults were present 20 days later with eggs containing ocellate miracidia after 21 days. The eggs hatch in utero; the miracidium contains a fully developed redia. Rediae of 2 size groups were present in the digestive gland of the brackish-water snail, Cerithidea californica. Megalurous cercariae are released and encyst on submerged objects. The stages of C. michiganensis resembled those of Parorchis acanthus, a philophthalmid also infecting C. californica, except for differences in the epidermal plate count of their miracidia and in their cercarial stage which was larger in P. acanthus and had a spinuous tegument with a collar of spines.