Save the Cracking Pearly Mussel

(Hemistena Lata) - Endangered Species


The Cracking Pearly Mussel can grow up to 90 mm in length, making it a medium sized mussel. It is brownish green to brown outer shell and broken dark green rays on the inside of it's shell. It is a fresh water mussel and can live up to 50 years. They start as larva and latch onto fish until they mature and then they burry themselves in the sand. The larva eat fish fluids and the mature mussels eat bacteria, algae, and detritus.

Where it is found!

It is located in the United States and resides in the free flowing rivers that flow through Alabama, Kentucky, Tennessee, Virginia, Indiana and Pennsylvania. Examples of these rivers are the Tennessee River below the Wilson Dam, Powell River, Clinch River, Green River, Elk River and the Ohio River. Cracking Pearly Mussels are found in gravel riffles, mud and sand bottoms of slow moving water. It buries itself in the gravel with only its feeding siphon exposed.

Why is it endangered?

Dams and reservoirs that have been built in these rivers have flooded most of the Cracking Pearly Mussels' habitat, by reducing its gravel/sand habitat. The dam also disrupt the distribution of fish hosts limiting the mussels ability to have larva mature. Also strip mining, logging, and farming around the rivers adds silt to the rivers which clog the mussels feeding siphons and smother it to death. Water pollution from agricultural and industrial run off leak into the water and toxic metals become concentrated in the mussels body tissues and it eventually poisons the mussel to death.

Ecological Importance?

The Cracking Pearly Mussel are water clarifiers, they filter suspended organic matter. They are considered aquatic decomposers and help the water stay clean for other organisms to survive. They are also a food source for many aquatic and terrestrial species.

Economic Importance?

They are an indicator species for water pollution. This can help notify humans when the water is getting to polluted and can become harmful for humans to swim in or use and for other species that would be used as a food source for us such as fish. This can also help show when water pollution is getting too high because it is better to clean up at little than a lot because it can get expensive.

Recovery Plan:

There was a recovery plan to be put in place July 11, 1991 to help clear the water of pollutants and and regulate the building of dams. And slowly reintroduce the species back into their environment. This plan unfortunately ended after a couple of years due to a lack of funding.


BY: Adrian Auchterlonie (3Red)