Life Cycle and Development of Prosthorhynchus formosus (Van Cleave, 1918) Travassos, 1926, an Acanthocephalan Parasite of Birds

Abstract

The life cycle of Prosthorhynchus formosus (Van Cleave, 1918) Travassos, 1926 is presented. The terrestrial isopods Armadillidium vulgare, Porcellio laevis, and P. scaber served as experimental intermediate hosts, and chickens and turkeys as experimental definitive hosts. After ingestion of the eggs by the isopod, the acanthor emerges from its shells within 15 min to 2 hr, enters the gut wall of its host, and remains there 15 to 25 days. It then migrates to the hemocoel and develops through the acanthella stage to the infective cystacanth by the 60th to 65th day of infection. Van Cleave (1918) described Plagiorhynchus formosus on the basis of four specimens collected from the flicker, Colaptes auratus, at Bowie, Maryland. In 1926, Travassos reassigned this species to the genus Prosthorhynchus but gave no reasons for the change. Van Cleave (1942) disagreed strongly with this change in generic status and reaffirmed its position in Plagiorhynchus. Golvan (1956) clarified the differences between Plagiorhynchus and Prosthorhynchus and defended its position in Prosthorhynchus. This view, which was upheld by Petrochenko (1956) and Yamaguti (1963), is accepted by the present authors. Jones (1928) extended the host list to include the chicken (Gallus domesticus), robin (Turdus migratorius), and the crow (Corvus americanus). She remarked on the possibilities of this worm becoming an important parasite of domestic fowl. Cuvillier (1934) added the catbird (Dumatella carolinensis), and a thrush Received for publication 17 April 1964. * Part of a thesis submitted by the senior author to the Graduate School of Colorado State University in partial fulfillment of the requirements for the Ph.D. degree, February 1964. This investigation was supported by Training Grant PHS-2E-94 (C2,3) from the National Institute of Allergy and Infectious Diseases of the National Institutes of Health, U. S. Public Health Service, and by a fellowship from the Boettcher Foundation, Denver, Colorado. (Hylocichla sp.), and Van Cleave (1942) the towhee (Pipilo erythrophthalmus), starling (Sturnus vulgaris), grackle (Quiscalus quiscala), and hermit thrush (Hylocichla guttata). Chandler and Rausch (1949) found it in the brown thrasher (Toxostoma rufum), and Hunter and Quay (1953) in Macgillivray's seaside sparrow (Ammospiza maritima macgillivaraii). The present report adds the red-shafted flicker (Colaptes cafer) and the domestic turkey (experimental). Sinitsin (1929) reported finding a juvenile of Plagiorhynchus formosus in the sowbug, Armadillidium vulgare, near Washington, D. C. To date, this is the only report on the life history of P. formosus, although Dollfus and Dalens (1960) reported larvae of Prosthorhynchus cylindraceus in A. vulgare in France. This work presents the complete life cycle of Prosthorhynchus formosus as observed under laboratory conditions, utilizing three species of terrestrial isopods as intermediate hosts and domestic fowl as definitive hosts. MATERIALS AND METHODS