The Microscopic Anatomy of the Freshwater Sponge, Ephydatia muelleri

Abstract

Ephydatia muelleri is a freshwater sponge abundantly found in the lakes and streams of Western Montana. In this study, the microscopic anatomy of E. muelleri in Salmon Lake, a lake located ca. 35 miles east of Missoula, MT, is described for specimens taken at ca. two week intervals between the months of May and August, 1994. The major cells (pinacocytes, choanocytes, and archaeocytes) are described. Although no sperm forming structures were noted, an egg and embryo indicate that sexual reproduction occurred.