Life Cycle of Metagonimoides oregonensis Price, 1931 (Trematoda: Heterophyidae) in North Carolina

Metagonimoides oregonensis (Heterophyidae: Digenea) Infection In Pleurocerid Snails and Desmognathus quadramaculatus Salamander Larvae In Southern Appalachian Streams

“…Variation in the morphology of adult M. oregonensis from Oregon and North Carolina has been previously noted (Lang et al, 1968). Here, we found initial evidence that cercariae morphology might also differ among populations.…”

“…The only heterophyids that have been identified as emerging from Pleurocera snails in streams in this region are M. oregonensis (Lang and Gleason, 1967;Lang, 1968). Indeed, Lang and Gleason (1967) state that ''a cercaria identical to that described for M. oregonensis by Burns and Pratt was found to emerge from the snail Goniobasis proxima collected from streams near Chapel Hill.'' The only other heterophyids in North America that commonly use amphibians as second intermediate hosts are species of Euryhelmis (Prudhoe and Bray, 1982;Sutherland, 2005).…”

“…However, Metagonimoides using Juga (5Oxytrema) nigrina appear to lack a free-swimming stage and form metacercariae only within the first intermediate snail host (Ingles, 1935). In North Carolina, Lang and Gleason (1967) suggested that there were no metacercariae formed within the snails hosts; all rediae produced free-swimming cercariae that leave the snail and infect larval stream salamanders, especially Desmognathus quadramaculatus, black-bellied salamanders. Lang et al (1968) followed up these studies on life cycle variation by examining adult parasites collected from raccoons in Oregon and North Carolina.…”

“…In North Carolina, Lang and Gleason (1967) suggested that there were no metacercariae formed within the snails hosts; all rediae produced free-swimming cercariae that leave the snail and infect larval stream salamanders, especially Desmognathus quadramaculatus, black-bellied salamanders. Lang et al (1968) followed up these studies on life cycle variation by examining adult parasites collected from raccoons in Oregon and North Carolina. They suggested that there were ''significant differences in morphology'' and that M. oregonensis from these different sites should be considered ''separate strains of the same species.''…”

“…A complex of cryptic Metagonimoides species may exist, so we caution that our usage of ''Metagonimoides oregonensis'' throughout the manuscript is based on current knowledge, and nomenclature may change with future studies. Since the study of Lang et al (1968), little work beyond the mention of M. oregonensis in host surveys (e.g., Goater et al, 1987) has been done on this parasite system.…”