Southworth, Darlene , Frank, Jonathan , Coffan, Robert .
Aquatic gilled mushrooms: Psathyrella fruiting in the Rogue River in southern Oregon.
A species of Psathyrella (Basidiomycota) with true gills has been observed fruiting underwater in the clear, cold, flowing waters of the upper Rogue River in Oregon. Fruiting bodies develop and mature in the main channel, constantly submerged, near aquatic vegetation, and were observed fruiting over 11 weeks. DNA sequence data place this fungus near Psathyrella brooksii. The underwater specimens differ from the type specimen in the ITS and 28S regions and may be a new species. These appear to be truly underwater mushrooms and not mushrooms fruiting on wood recently washed into the river. Substrates include water-logged wood, gravel, and the silty river bed. Water constrains spore dispersal. Spores were observed as wedge-shaped rafts released into a gas pocket under the cap. Underwater gills and ballistospores indicate a recent adaptation to the stream environment. This particular river habitat combines the characteristics of spring-fed flows, clear, cold, aerated water with woody debris in shallow depths on a fine volcanic substrate. The presence of nitrogen-fixing cyanobacteria near fruiting body attachment sites suggests a source of nitrogen in an otherwise clear stream. This observation adds to the biodiversity of stream fungi that degrade woody substrates. This is a new habitat for gilled mushrooms.
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1 - Southern Oregon University, Department of Biology, 1250 Siskiyou Blvd, Ashland, Oregon, 97520-5010, USA
2 - Southern Oregon University, Environmental Studies, Ashland, OR, 97520, USA
Presentation Type: Poster:Posters for Sections
Location: Ball Room & Party Room/SUB
Date: Monday, July 28th, 2008
Time: 12:30 PM