Ptychobranchus subtentum is an interesting mussel for a couple reasons. First, it is part of the assemblage of freshwater mussels endemic to the Cumberland and Tennessee rivers in Kentucky, Tennessee, Alabama and Virginia. Second, the genus Ptychobranchus has unique modifications for brooding its larvae and delivering them to their host fish. Some amazing pictures can be found at Chris Barnhart's Unio Gallery page about the Fluted Kidneyshell.
Classification:
Phylum Mollusca
Class Bivalvia
Subclass Palaeoheterodonta
Order Unionoida
Superfamily Unionoidea Rafinesque, 1820
Family Unionidae s.s.
Subfamily Ambleminae Rafinesque, 1820
Tribe Lampsilini von Ihering, 1901
Genus Ptychobranchus Simpson, 1900
Species Ptychobranchus subtentum (Say, 1825)
