The Description of Euryhelmis pacificus N. SP., and Notes on its Life Cycle

Author: Clyde Senger
Advisor: Ralph W. Macy
Year: 1952

Summary: A new species of Heterophyidae, Euryhelmis pacificus, has been found in the mink and muskrat in western Oregon. It can clearly be differentiated from the other species of Euryhelmis by its characteristic shape. The life cycle has been proven to involve the Pacific Giant Salamander, Dicamptodon ensatus (Eschscholts) as the second intermediate host. The metacercaria, which are located in the striated muscle of the salamander, will mature in three days when fed to white rats. Note has been taken of the viability of both the metacercaria and the adults. Measurements from a large number of flukes have shown that there is a definite variation in size between those in the mink and those in the muskrat. The taxonomic position of the fluke is mentioned.

[The only muskrat found to be infected with E. pacificus was the one taken from the Reed canyon. A Pacific Giant Salamander taken from the Reed canyon was "very heavily infected" with E. pacificus.]