About Unio tumidus Philipsson, 1788
Unio tumidus Philipsson, 1788, commonly called the swollen river mussel, is a species of freshwater mussel. It is an aquatic bivalve mollusc that belongs to the family Unionidae, which are commonly referred to as river mussels. One recognized extinct subspecies is † Unio tumidus ludwigi Wenz, 1922. This mussel is native to Europe. Confirmed occurrences within its native range include Croatia, the Czech Republic (found in both Bohemia and Moravia, where it is classified as vulnerable, VU), Germany (classified as highly endangered, with the status "Stark gefährdet", and listed as a specially protected species in annex 1 of the Bundesartenschutzverordnung), Latvia, Lithuania (classified as vulnerable), the Netherlands, Poland, Slovakia, Sweden, and the British Isles (specifically in England).
