Lasmigona decorata

The Carolina heelsplitter (Lasmigona decorata) is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae. It is named the 'Carolina heelsplitter' because in life the sharp edge of the valves protrudes from the substrate and could cut the foot of someone walking on the river or stream bed. This species is endemic to the United States and is found in only North Carolina and South Carolina. This species current status is classified as 'critically endangered'. The IUCN Red List website states that to be considered critically endangered means that the species is facing an extremely high risk of becoming extinct in the wild in the immediate future. The first recorded encounter with the Carolina heelsplitter was in 1852 by Isaac Lea. He described this new creature as Unio decoratus. The largest recorded specimen was about five inches long. This freshwater mussel has a shell which is greenish-brown to dark brown on the outside. The inside of the shell usually has nacre that is pearly white or bluish-white, although the nacre can be pale orange in older specimens. The younger individuals tend to have faint black or greenish-brown rays on the outer surface of the shell.