Great Basin Naturalist


Posthodiplostomum minimum (MacCallum 1921), a strigeoid trematode normally found in the intestine of piscivorous birds, has been shown to be capable of developing in 17 orders of amphibian, reptilian, avian, and mammalian hosts. Both Physa gyrina and Lymnaea reflexa serve as the first intermediate host. Only sunfish from the lakes region were infected with metacercariae of P. minimum, indicating the presence of two physiologically distinct strains of Posthodiplostomum. Extensive feeding experiments involving all four vertebrate classes of hosts demonstrated the lack of host specificity in this genus.