An Arizona-based nonprofit said Monday it plans to sue the federal government over the protection of a rare fish in Limestone County.

The Center for Biological Diversity said in a news release that the spring pygmy sunfish is being threatened by the development of a new Mazda-Toyota joint vehicle assembly plant in a Huntsville-annexed portion of Limestone County.

Mazda and Toyota officials said the $1.6 billion plant is expected to bring in about 4,000 jobs. Production is scheduled to begin in 2021.

The center states in the release that the sunfish -- which is found in Beaverdam Creek in the Mooresville area -- should already have a critical habitat designated. The center said it intends to sue the U.S. Fish and Wildlife Service for not designating the habitat under the Endangered Species Act.

In 2013, the U.S. Fish and Wildlife Service declared the sunfish was protected under the act, and the service said it planned to designate more than 1,600 acres around the creek as a protected critical habitat. That still hasn't happened, according to the Center for Biological Diversity.

The Mazda-Toyota plant will bring construction and new roads that will hurt water quality and disrupt water flow to the spring, which could destroy the fish and make it extinct.

"Reckless development has already sent this little fish diving toward the brink of extinction," Center attorney Elise Barnett said in the release. "The Fish and Wildlife Service needs to protect the sunfish’s habitat immediately before this massive manufacturing plant destroys what’s left of it.”