Studies on the Biology of Philophthalmus gralli Mathis and Leger, 1910 (Trematoda: Digenea)

Abstract

The adult of Philophthalmus gralli occurs in the orbit of wild birds and has been obtained experimentally in chicks. Rodents were refractory to infection by the oral route. Goniobasis spp. and Pleurocera acuta serve as molluscan hosts. The miracidium penetrates the snail only far enough to release a single redia. It localizes in the heart and produces daughter rediae which migrate to the digestive gland and produce megalurous cercariae. Cercariae escape and encyst on the exoskeleton of arthropods which are eaten by the definitive host, in which the worms migrate to the eye by way of the nasolacrimal duct. Factors concerned with such migration are considered and all stages in the life history are described. The family Ommatobrephidae is reduced to synonymy with the Philophthalmidae and the species Philophthalmus nyrocae to synonymy with Philophthalmus gralli.