Studies on the Helminth Fauna of Iowa. I. Trematodes of Amphibians

Abstract

A survey of 542 amphibians collected during 1953-1967 from 40 areas of northwest Iowa reveals an incidence of 52.8% infection with digenetic trematodes. Almost all represent new locality records. Hosts examined include Ambystoma tigrinum (Green), Bufo americanus Holbrook, Bufo cognatus Say, Acris crepitans Baird, Hyla versicolor LeConte, Pseudacris triseriata (Wied), Rana catesbeiana Shaw, and Rana pipiens Schreber. Fifteen species of flukes are included in the collection, 14 of which are harbored by Rana pipiens (leopard frog), the most abundant host in the region. A summary of pertinent literature relating to each species of trematode. is presented, together with 20 illustrations. The trematode fauna of amphibians of the United States is quite varied and has been the subject of numerous investigations. Early compilations by Stiles and Hassall (1894) and by Pratt (1900, 1904) were followed by the first comprehensive systematic accounts of Stafford (1902a,b, 1905), who published several reports on helminths of North American vertebrates. Later studies on amphibian helminths from the United States include those by Cort (1912, 1915a), Harwood (1932), Brandt (1936), Ingles (1936), Rankin (1937), Manter (1938), Kuntz (1940), Parker (1941), Kuntz and Self (1944), Rankin (1945), Bouchard (1951), Lehmann (1954, 1956, 1960), Odlaug (1954), Najarian (1955), Frandsen and Grundmann (1960), Waitz (1961) and Campbell (1967). Pratt and McCauley (1961) compiled an annotated catalogue of the trematodes of the Pacific northwest. A series of abstracts and papers published by Walton (1942-1962)1 included a worldwide compilation of amphibian hosts, parasites and their geographic distribution. This information, together with a comprehensive bibliography, was published in microcard form in 1964. The herculean effort of Yamaguti (1958) to bring together an account of all genera of digenetic trematodes of vertebrates has provided a useful summary of the literature up to 1955. Published accounts of the helminth fauna of Iowa are regrettablv meager. Since 1953, an extensive survey of helminths of vertebrates within the state has been under way and has resulted in the examination of several thousand hosts. This report, the first in a series devoted to the helminths of Iowa vertebrates, is concerned with trematodes of amphibians, particularly those from the lakes region of northwestern Iowa. 1 For a listing of these reports, see the U.S. Dep. Agriculture Index Catalogue of Medical and Veterinary Zoology, Part 17 (1952) (Authors) and subsequent supplements.