corbicula here photographed in a mineral encrustation active area (algal and or bacterial origin) photographed (in August 2016) on the bottom of the river "Sèvre Niortaise" in a shallow and well lit place, called "Roman Bridge of
Azay-le-Brûlé "(France). On these crusts various invertebrates, including
gammares and many
w:Theodoxus can be observed. This section of the river is rich in crusting areas that typically form it from horizontal carpet aquatic of mosses (bryophyta) or vertical carpet of
Marchantiophyta. Note: Not very thick crust (more than a few cm thick) are found on the battery or the medieval bridge on rocks a priori old, suggesting that the phenomenon is recent.Another note: the crusts are not on lead sinkers (metal toxic and
Ecotoxical) neither on some rocks or on pieces of dead wood (to be confirmed by more attentive observations).