Powell, Porter and Longcore The microscopic aquatic fungi known as chytrids have recently received notoriety because a new parasitic species (described by co-PI Dr. Joyce Longcore) is implicated in the population decline of amphibians in various parts of the world. Confusion over the status and role of this organism has highlighted the poor state of taxonomic knowledge of these fungi, which are now the focus of this major research and training project. A "chytrid consortium" combines the talents of the leading researchers in the U.S. to apply morphological, culturing, ultrastructural (electron microscopy), and molecular DNA sequencing technologies to problems of classification, identification, and phylogeny of these ecologically interesting microbes. Recent molecular phylogenetic analyses of 18S ribosomal DNA sequences from various members of the traditionally recognized "phycomycetes" have demonstrated the polyphyletic nature of this group, and have helped delimit a more natural assemblage of chytrid fungi, possibly encompassing 1500 or so described species in the world. Studies of laboratory-cultured strains and new field collections are planned, to investigate morphological, ultrastructural, and molecular features that yield reliable diagnostic characters for species- and genus-level discrimination. Outcomes of the project include comprehensive taxonomic monographs of natural groups within the order Chytridiales, an interactive and image-based identification key available on the Web, and the development of new cryopreservation methods for long-term storage and culturing of these organisms, for future molecular and biotechnological studies. The chytrid consortium includes specialists at the universities of Alabama, Georgia, and Maine, along with colleagues with additional expertise in modern systematics practice and theory, all of whom will participate in mycological training at graduate and undergraduate levels. A series of yearly workshops will highlight recent scientific and technological developments, and will incorporate work done by Dr. Daniel Wubah at Towson State University, who specializes on fungi adapted as parasites and commensals in the intestines of animals. Dissemination of results and products will build upon a website currently maintained at the University of Maine for the zoosporic fungi of the world.