A New Type of Metacercarial Cyst of the Genus Apophallus, from the Perch, Perca flavescens, in Minnesota

Abstract

A new type of cyst containing a metacercaria with the characters of the genus Apophallus, but differing considerably from any Apophallus cysts previously described, was found imbedded in the musculature of the common perch, Perca flavescens, in northern Minnesota. These cysts were present in all of 30 perch examined from Lake Itasca and in a single large perch, about 12 inches in length, examined from Leech Lake. The fish from the first lake varied from two to eight inches in length. A few cysts were also found in one of a number of minnows, Notropis sp., from Lake Itasca, but they were not found in Fundulus diaphanus, Esox lucius, Stizostedion vitreum or Ambloplites rupestris, although several of each were examined. Following is a description of the cysts and of the contained metacercaria, for which the name Apophallus itascensis is proposed, a report of negative experimental feedings, and a discussion of the relation of this parasite to other species of the genus. Grateful acknowledgement is made of the assistance given by Dr. Asa C. Chandler in the course of this study.