WESLACO – A species of mussels found in the Rio Grande is now on the U.S. endangered species list.

Texas Hornshell Mussels were added to the list in February.

Roel Lopez, director of the Texas A&M Natural Resources Institute, says these freshwater mussels prefer narrow areas of rivers and streams with sand, clay or gravel bottoms.

He said he’s concerned what the decline of the Texas Hornshell means for the water quality of the river.

Watch the video above for more information.