Aquatic Phycomycetes of Lily Lake, Utah

Authors

Hugh M. Rooney, Virginia Poltechnic Institute and State University, Blacksburg, Virginia
Kent H. McKnight, Plant Protection Institute, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, Maryland

Abstract

During the ice-free period from May to November on two successive summers water molds were collected on 14 different substrata placed in Lily Lake, a subalpine bog lake in the Uinta Mountains of Utah. Twenty-five collections yielded thirty-four species in 20 genera, 11 families, and 6 orders of aquatic Phycomycetes. Correlation of frequency presence of the species reported with physical and chemical characteristics of the lake showed that the number of species collected increased with an increase in water temperature and a decrease in oxygen content during June to August, reaching a peak in late July. Rhipidium americanum Thaxter (100 percent frequency) and Sapromyces androgynus Thaxter (72 percent frequency) were the most common species and the species found on more different substrata than any others. Also in the "very abundant" group were Saprolegnia ferax (Gruith.) Thurent and Achlya sp., both with 64 percent frequency.