Gut fungi of isopods: the genus Palavascia

The genus Palavascia is revised, and the first record and new species of th is genus in the Southern Hemisphere is described from the Patagonia region of Argentina. Palavascia patagonica shares some similarities with the other two species of the genus but it possesses very distinct features such as a U-shaped extension at its base and a ringed holdfast. The worldwide distri bution of the genus is analyzed and new records and hosts for P. sphaeromae are reported. Evolutionary hypotheses for the origin of the isopod-fungi r elationship are proposed.