Robuta

https://www.fws.gov/apps/species/wheelers-pearly-mussel-arcidens-wheeleri Wheeler's Pearly Mussel (Arcidens wheeleri) | U.S. Fish & Wildlife Service wheeler s pearly mussel arcidens wheeleri fish wildlife service https://www.fws.gov/media/birdwing-pearly-mussel-inside Birdwing pearly mussel (inside) | FWS.gov pearly mussel birdwing inside fws