by US Fish & Wildlife Service
Official Status: Endangered. Endangered species are animals and plants in danger of extinction throughout all or a significant portion of their range. It is unlawful to kill, harm, or harass endangered species.
Listed: 55 Federal Register 36641; September 6, 1990.
Historical Status: Historically, pallid sturgeon were found in the Missouri River from Fort Benton, Montana, to St. Louis, Missouri; in the Mississippi River from above St. Louis to the Gulf; and in the lower reaches of other large tributaries, such as the Yellowstone, Platte, Kansas, Ohio, Arkansas, Red, and Sunflower; and in the first 60 miles of the Atchafalaya River.
Present Status: Pallid sturgeon populations are fragmented by dams on the Missouri River. Pallid sturgeon are scarce in the upper Missouri River above Ft. Peck Reservoir; in the Missouri and lower Yellowstone Rivers between Ft. Peck Dam and Lake Sakakawea; in the Missouri River downstream of Gavins Point Dam; and in the Mississippi and Atchafalaya Rivers.
Habitat: Large rivers with high turbidity and a natural flow. Preferred habitat has a diversity of depths and velocities formed by braided channels, sandbars, islands, sand flats and gravel bars.
Life History: Sexual maturity for males is estimated to be 7-9 years, with up to 3 years between spawns. Females are not expected to reach sexual maturity until 7-15 years, with up to 10-year intervals between spawning. Pallid sturgeons are long lived, with individuals perhaps reaching 60 years of age or more.
Aid to Identification: Pallid sturgeon have a unique prehistoric appearance. They have a flattened snout, long slender tail and are armored with five lengthwise rows of bony plates instead of scales. Their mouth is toothless and positioned under the snout for sucking small fishes and invertebrates from the river bottom. Pallid sturgeon can weigh up to 80 pounds and reach lengths of 6 feet, whereas the closely-related shovelnose sturgeon rarely weighs more than 8 pounds. The back and sides of pallid sturgeons are grayish-white, versus the brownish tan color of the shovelnose sturgeons.
Reasons for Decline: Habitat loss and modification from construction of dams and channelization of rivers. Commercial fishing and environmental contaminants may have also played a role in the pallid sturgeons decline. Hybridization with the more common shovelnose sturgeon is a threat to the species and may be due to habitat modifications.
Recommendations: All species of sturgeon caught in North Dakota must be released immediately. Contact the U.S. Fish and Wildlife Service with information on any pallid sturgeon you catch.
Comments: Population augmentation and propagation has occurred to address poor recruitment of juveniles into the population. Current populations are composed of older fish that will die in the near future. Stocking now will ensure a breeding population for future recovery efforts; however, habitat restoration will also be essential to recover this species.
References: Pallid Sturgeon Recovery Plan, Fish and Wildlife Service, November 1993.
by U.S. Fish & Wildlife Service