Two fruiting bodies (one already degraded) of a subaquatic fungus species photographed underwater (at about 60 cm deep), on an oak beam covered with filamentous algae, zebra mussels and here a freshwater sponge (spongilla lacustris) in the Mid-Deûle, in northern France. Air bubbles are probably produced by algae or sponges (photosynthetic) (perhaps Psathyrella sp.?)