The Pallid sturgeon (Scaphirhynchus albus) is an endangered species of fish that exists in the waters of the Mississippi and Missouri River and numerous tributaries. In 1990, the U.S. Fish and Wildlife Service placed the species on the endangered species list, as very few young sturgeon had been found in recent years, and also due to the fact that all sightings of the fish had lessened in the preceding decade.
The Pallid sturgeon is one of the largest fish found in the Mississippi drainage. The larger specimens that have been caught are over 60 in (152 cm) in length and weigh 85 lbs (39 kg). Pallid Sturgeons are extremely long lived fish, with estimates of their lifespan in the wild averaging 60 years. The Pallid has a shovel nosed snout, toothless mouth, bony plates and a tail that is reptilian in appearance. In color they are usually light brown with a white underside. From the dorsal fin to the tail fin, the Pallid sturgeon has an armored backside of cartilage and a soft fleshy underside and nowhere on the fish are scales as are found in more modern species. The Pallid is a relic of the dinosaur era and has been called the “ugliest fish in North America”.
The Pallid usually takes a decade to mature and become able to reproduce. The fish spawns between the months of June and August and can produce thousands of eggs. In 2005, nine specimens in a fish hatchery (6 males and 3 females) produced 400,000 eggs. However, the eggs produced in the wild are considered to be uncommon and are heavily subject to predation and other forces of nature.
The Pallid sturgeon is thought to have become endangered due to loss of habitat. The vast majority of the Mississippi River drainage system has been channeled and dammed, thus reducing gravel deposits and slow moving side channels that are favored spawning areas. The fish was relatively common until the middle of the 20th century, and anglers found the prize of landing such a large fish in fresh water a rewarding experience. The Pallid is also considered to be an excellent tasting fish, and like many sturgeon, the eggs have been used as caviar, though this was uncommon with this species. Current populations of the fish are small and the fish is now rarely seen in the wild. The Pallid was the first fish species in the Mississippi drainage that was listed as an endangered species.
Efforts to restore the endangered fish have yet to yield positive results. Capturing a young Pallid has become a rare event since the 1980’s. With the major alterations to natural spawning areas that have occurred throughout their native habitat, restoration of spawning areas throughout the Mississippi drainage basin will be mandatory if the species is to be expected to survive in the wild. Active efforts using fish hatcheries for spawning may help to ensure the species continues to exist, but this existence is heavily dependent on human assistance. In at least one situation, researchers have implanted sonic transmitters in sturgeons, making it easier to track their movements and help identify possible spawning areas.