North America has been exclusively blessed with a wide variety of freshwater mussel species, the envy of many foreign shell collectors. Of the 300 American species, 50 are found in Texas. They inhabit our streams, rivers, and lakes, filtering toxins from the water and providing food for many aquatic organisms. Their utilitarian shells are not very pretty, but their rugged lines and irregular shapes create a unique attraction that enchants collectors the world over. They truly are a Texas treasure.
Unfortunately, their sensitivity to environmental changes makes these animals extremely vulnerable to extinction. Pollution, dam building, and competition from invasive species have played major roles in destabilizing native mussel populations. As much as 10% of all freshwater mussel species are extinct; of those that remain, 70% are considered under threat by the U.S. Fish and Wildlife Service.