Pallid Sturgeon

The pallid sturgeon (Scaphirhynchus albus) is an endangered species of ray-finned fish, endemic to the waters of the Missouri and lower Mississippi River basins of the United States. Named for its pale coloration, the pallid sturgeon is closely related to the relatively common shovelnose sturgeon (Scaphirhyncus platorhynchus), but is much larger, averaging between 30 and 60 inches (760 and 1,500 mm) in length and 85 pounds (39 kg) in weight at maturity. The pallid sturgeon takes 15 years to mature and spawns infrequently, but can live for up to a century. A member of the Acipenseridae (sturgeon) family of fish that originated during the Cretaceous period 70 million years ago, the pallid sturgeon has remained essentially unchanged. The species is considered to be a relict of the dinosaur era, and has been called "one of the ugliest fish in North America".

In 1990, the U.S. Fish and Wildlife Service (USFWS) placed the pallid sturgeon on the endangered species list, because few young individuals had been observed in the preceding decade, and sightings had greatly diminished; the species is now rarely seen in the wild. It was the first fish species in the Mississippi River drainage area to be listed as endangered, and a loss of its habitat is thought to be responsible for its decline. The vast majority of the Mississippi River drainage system has been channeled and dammed, reducing the gravel deposits and slow-moving side channels that are its favored spawning areas. Until the middle of the 20th century, pallid sturgeon were common and anglers found catching such a large fish in fresh water a rewarding experience. The species is considered to be good-tasting, and its eggs have been used as caviar, although less commonly than those of many other sturgeon.

Efforts to prevent the species from becoming extinct have had modest success. Pallid sturgeon are actively being raised in a dozen hatcheries and the offspring are being released back to the wild every year. To better understand pallid sturgeon behavior, researchers have implanted GPS transmitters to track their movements and help identify possible spawning areas. Federal and state agencies are working together to improve habitat by restoring spawning areas since restoration of these areas is required if the species is to survive in the wild.