The U.S. Fish and Wildlife Service on Tuesday announced it’s proposing protections for a rare freshwater mussel historically found in 10 states.

The at-risk green floater is a small freshwater mussel found in small streams and large rivers in the eastern United States, the federal agency reported.

The short-lived green floater is near endangerment due to “the loss, fragmentation, and degradation of its aquatic habitat,” the service told USA TODAY.

The agency said it is proposing to list the mussel as threatened under the Endangered Species Act.

What states historically have green floaters?

The mussel is historically native to the District of Columbia and the following 10 states:

  • Alabama
  • Georgia
  • Maryland
  • New Jersey
  • New York
  • North Carolina
  • Pennsylvania
  • Tennessee
  • Virginia
  • West Virginia.

As of Tuesday, the green floater could still be found in seven states within its native range: Maryland, New York, North Carolina, Pennsylvania, Tennessee, Virginia and West Virginia.

But wildlife officials said there are no recent records of green floater from New Jersey or D.C., and green floaters were considered eradicated in Alabama and Georgia.

What is a green floater mussel?

The U.S. Fish and Wildlife Service oversees management of endangered species including the green mussel which have ovate trapezoidal shaped shells.

Their shells are yellowish brown or olive green and adults rarely exceed 2.17 inches, according to the North Carolina Wildlife Commission.

The species were first found in Pennsylvania, according to a fact sheet rom the commission, are omnivore and eat microscopic matter including bacteria and algae, the agency said. Their lifespan is three to four years.