KNOXVILLE (AP) — The Tennessee Valley Authority says its biologists have discovered a new species of fish in streams in Tennessee.

TVA officials say the fish species, Percina apina, lives in the Duck River tributary streams in middle Tennessee.

TVA aquatic biologist Jeff Simmons, who helped discover the fish, named it after the clean, clear waters where it lives.

TVA says the Logperch species needs silt-free substrates to thrive as it hunts aquatic insect larvaem including blackfly, caddisfly, mayfly and stonefly.

TVA says the discovery of the fish shows water quality work in the Tennessee River Watershed is working.

TVA monitors more than 700 sites for water quality throughout the Tennessee Valley.

The nation's largest public utility powers 9 million customers in parts of seven Southern states.