Fragile Legacy
Endangered, Threatened & Rare Animals of South Dakota
Pallid Sturgeon (Scaphirhynchus albus)
Status: FE, SE
Description: The pallid sturgeon is one of the largest (30-60 inches, 76-152 cm) fishes found in the Missouri-Mississippi River drainage, with specimens weighing up to 85 pounds (39 kg). It is usually light brown on the dorsal surface and white underneath. It has a flattened, shovel-shaped snout. Fleshy chin barbels are located at about 1/3 the distance between the mouth and snout, with the inner barbels about 1/2 the length of the outer barbels. The pallid has a long, slender, flattened and armored region from the dorsal fin to the tail fin (caudal peduncle), which has a long upper lobe. There are no bony plates on the belly.
Habitat and Habits: This species is a bottom dweller, found in areas of strong current and firm sand bottom in the main channel of large turbid rivers such as the Missouri River. The pallid sturgeon is a member of a primitive family (Acipenseridae) which, like other sturgeon, has lengthwise rows of bony plates covering its body, rather than scales. Pallids are slow-growing, late-maturing fish that feed on small fishes and immature aquatic insects. Spawning occurs from June through August.
Distribution: The pallid sturgeon is distributed from the headwaters of the Missouri River (Fort Benton-Great Falls, Montana) through the Mississippi River to New Orleans, Louisiana.
Conservation Measures: Virtually the entire range of the pallid sturgeon has been altered in some way. Normal movements have been blocked by dam construction. Alteration of water quality, temperature and flow pattems, as well as reduced spawning habitat, have reduced the overall habitat diversity of the pallid sturgeon, threatening the species' survival.
As a result of these habitat changes, no successful pallid sturgeon reproduction has been documented in recent history and the pallid was federally listed as endangered in 1990. Most sightings of this species in South Dakota since 1980 have occurred in the Missouri River reservoirs of Lakes Lewis and Clark, Sharpe and Oahe.
Recent research efforts in South Dakota and Montana have included implanting of sonic transmitters into pallids, to leam more about habitat needs and movement patterns and to locate spawning areas or other concentration sites. Successful propagation of other sturgeon species may assist with captive breeding of pallid sturgeon, if enough pallids can be found in the wild.
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