Abstract
SYNOPSIS. Myxidium serotinum was found in 51 of 58 (87.9%) specimens of the two‐lined salamander, Eurycea bislineata, from West Virginia. This constitutes a new host record. No specimens of the order Salientia, or other species of the order Caudata were infected. Eurycea bislineata appears to be the normal host of M. serotinum, which is specific for the gallbladder in a variety of amphibian hosts. Apparently, larval E. bislineata becomes infected with M. serotinum, and the parasite does not become a mature trophozoite until after the tadpoles metamorphose to the adult salamander. Certain host hormonal factors may be important to the maturation of M. serotinum.