Center for Biological Diversity

For Immediate Release, March 17, 2023


Tierra Curry, (928) 522-3681,

Two Southern Freshwater Mussels Proposed for Endangered Species Protection

Mussels Live in Texas, Louisiana, Arkansas, Mississippi, Oklahoma

DALLAS— In response to a Center for Biological Diversity lawsuit, the U.S. Fish and Wildlife Service today proposed protection for two freshwater mussels in five southern states and designated 1,860 river miles as critical habitat.

“These long-overdue protections for the Texas heelsplitter and Louisiana pigtoe would toss a lifeline to two special critters that won’t survive without Endangered Species Act safeguards,” said Tierra Curry, a senior scientist at the Center. “Freshwater mussels tell us a lot about water quality, and their decline sends a warning that we need to do a better job of protecting rivers, for their sake and ours.”

The Texas heelsplitter and Louisiana pigtoe are threatened by water pollution, declining river flows and higher water temperatures resulting from climate change. The rivers where the mussels live are being polluted by wastewater treatment plants, oil and gas development, and sand and gravel mining.

The Texas heelsplitter, named for its sharp shell, is 7 inches long with a tan to black elliptical shell and may live up to 50 years. Texas heelsplitters live in the Trinity, Neches and Sabine rivers in east Texas and western Louisiana. There are only five remaining populations — all of which are on the brink of extinction. The proposed critical habitat for the Texas heelsplitter includes 832 river miles in 31 counties in Texas.

The Louisiana pigtoe has a brown to black triangular shell with green rays and grows to 2.5 inches long. There are 13 remaining populations, but only two are considered to be healthy. The Louisiana pigtoe lives in rivers in east Texas, including the Big Cypress-Sulphur, Neches-Angelina, Sabine and San Jacinto. In Louisiana the species is found in the Calcasieu, Sabine and Pearl rivers. The mussels also occur in the Cossatot, Saline, Rolling Fork and Little rivers in Arkansas, the Little River in southeast Oklahoma, and the Pearl River in Mississippi.

The proposed critical habitat for the Louisiana pigtoe consists of 1,028 river miles in 21 counties in Texas, three counties in Arkansas, six parishes in Louisiana, two counties in Mississippi, and one county in Oklahoma.

The Texas heelsplitter was put on a waiting list for Endangered Species Act protection in 1989. The conservation group Wild Earth Guardians filed a formal petition in 2007 for protection of the two mussels. In 2020 the Center sued the Service for leaving both species to languish on the candidate list.

Passed 50 years ago, the Endangered Species Act has saved 99% of the plants and animals under its care, including the bald eagle, brown pelican, American alligator and humpback whale.

Louisiana pigtoe. Credit: USFWS. Image is available for media use.
Texas Heelsplitter. Credit: USFWS. Image is available for media use.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.

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