U.S. & Wildlife Service because successful reproduction has not been docu- spawning and growing season in order to serve the mented. It is also likely that the forage base once used needs of commercial navigation. Biologists recom- by pallid has been greatly altered, thus mend that these procedures be altered to include a affecting both growth and reproduction. The largest Spring water level Pallid Sturgeon remaining populations of pallid sturgeon appear to be rise, followed by a in the upper above Ft. Peck Reservoir mid-Summer albus in ; in the Missouri and Yellowstone rivers reduction in flows above Garrison Reservoir in North Dakota and and water levels in Montana, respectively; in the below order to simulate St. Louis, Missouri to the Old River Control Structure characteristics of in ; and below the Old River Control the natural river Structure in the Atchafalaya and Red rivers of Louisi- hydrograph that ana. the pallid sturgeon evolved under. Lisbon Bottoms Habitat Restora- Artificial Propagation: Pallid sturgeon were first The Spring rise tion Site. artificially spawned by Missouri Department of would trigger spawning activity, and the summer flow Conservation biologists in 1992. A number of other reduction would maintain lower flows and quieter Federal and State resource agencies are now also water for the rearing and feeding of young pallid involved in their own propagation activities. About sturgeon. This procedure would also allow for com- 10,000 hatchery reared pallids were stocked in the mercial navigation traffic to transport fertilizers and lower Missouri and Middle Mississippi rivers in the fuel upstream on the “Spring rise”, and harvested crops mid 1990’s. Several thousand more hatchery produced downstream on a “Fall rise”. However, this procedure fish were subsequently stocked in the upper Missouri has not been implemented due to political opposition and lower reaches of the Mississippi through the coming largely from farming and navigation industry combined efforts of state and federal biologists. representatives. Also the Pallid Sturgeon Recovery Plan, prepared by the Pallid Sturgeon Recovery Team, Human Uses: Aside from the pallid sturgeon’s has not been fully implemented, largely due to lack of Description: The pallid sturgeon, an ancient species importance as a natural inhabitant of the Missouri and funding support. that has existed since the days of the dinosaurs, is also Mississippi River systems, it is considered an indicator one of the most poorly known and infrequently seen species whose abundance and distribution is directly What can you do? Immediately release any fish freshwater in North American. It was listed by related to the quantity and quality of suitable habitats captured or caught on hook and line that is thought to the U.S. Fish & Wildlife Service as endangered on and riverine hydrology. be a pallid sturgeon. Become better informed about September 6, 1990, in accordance with provisions of needs, and support both state and the Endangered Species Act of 1973, as amended. What is being done to protect the pallid sturgeon? federal endangered species recovery programs, Similar in appearance to the , the A Pallid Sturgeon Recovery Plan has been established including the Pallid Sturgeon Recovery Plan. With a pallid has a flattened and shovel-shaped snout and is by the U.S. Fish and Wildlife Service, in cooperation little help, these “living fossils” can live along side of with state and private entities, under the auspices of the thriving economies and modern man! Endangered Species Act of 1973, as amended. This plan includes habitat restoration to reconnect the river For more information contact: with side channels and quiet backwater habitats (e.g. Lisbon Bottoms); strategies for restoring riverine flow U.S. Fish and Wildlife Service distinguished by pale, bony plates instead of scales, a regimes to some semblance of their natural character; La Crosse Fishery Resources Office reptile-like body, a sucker-type mouth and large and artificial propagation. Under present management 555 Lester Avenue barbels (whisker-like growths next to it’s mouth). The procedures of the U.S. Army, Corps of Engineers, Onalaska, Wisconsin 54650 barbels, used to sense the river bottom and identify Missouri River flows below Gavin’s Point dam (the (608) 783-8434 prey, allow the protrusible, vacuum cleaner-like mouth most downstream Missouri River reservoir) are raised to quickly capture it. Prey consists of aquatic insects in the Spring and held stable throughout the summer Revised 2 May 2001 and small bottom dwelling fish. The caudal peduncle smallest of the two successfully fed goldfish, crayfish, and minnows. (or tail) of the pallid sturgeon is flattened in cross weighed approxi- section, completely covered with armor-like plates, and mately 2 lbs, and Historic and Present Range: The original range and the upper lobe of the tail fin is elongate and shark-like. both were believed distribution of pallid sturgeon (see map) included the The pallid is lighter in color (greyish-white) than the to be less than three (from the confluence of the Bighorn shovelnose (tan to gray or yellowish green dorsally and years old, indicat- River downstream to the confluence of the Missouri light ventrally) and is much larger in maximum size. ing recent pallid River), the Missouri River (from Great Falls, Montana, While the shovelnose sturgeon rarely exceeds 5 lbs in sturgeon reproduc- downstream weight, the pallid can exceed 6 ft. in length and weigh tion in the area. to the Pallids can live confluence beyond 60 years of of the age, but do not Mississippi reach sexual River), and maturity until about Larval pallid sturgeon collected the Missis- age 20. Pallid at Lisbon Bottoms habitat sippi River sturgeon are known restoration site. (from the Historic Range and Distribution of to hybridize in confluence Pallid Sturgeon. nature with the closely related shovelnose, and it is of the thought that loss of habitat and reproductive cues Missouri River to the Gulf of Mexico). The one or two (water level rises) are the likely causes. Since the two early records of pallid sturgeon from the Mississippi sturgeon species are so closely related, and their former River above the confluence of the Missouri River were unique spawning habitats have been altered or lost likely strays because prior to construction of naviga- over 100 lbs. Also, the belly of the pallid sturgeon is largely due to damming, altered hydrology, and tional features, the upper Mississippi River probably completely without bony plates throughout its life and channelization, both species are forced to at the did not provide the preferred turbidity and temperature the barbels are positioned differently (see figure few remaining acceptable locations. Fertilization range of the species. Historic abundance of pallid above). In the shovelnose, all four barbels are in line occurs externally, and hybridization occurs when sturgeon is poorly known, but available information and evenly spaced in front of the mouth. In the pallid, and sperm of the two species are mixed in the river suggests that the species was always rare. In the early the outer barbels are placed slightly farther back. water as it flows over the gravelly spawning beds. In 1900’s, pallid sturgeon reportedly comprised only 1 in the lower Missouri and in the Missouri reach of the 500 of river sturgeon captured in the Mississippi River Biology: While little is known about pallid sturgeon Mississippi River (below St. Louis), hybrids are more at Grafton, Illinois. Since development of the Missouri life requirements, we do know that they prefer large, common than pallids. Hybrids were first identified in River dams and reservoirs, the species has declined turbid, free-flowing riverine habitats with rocky that reach of the Mississippi River in the late 1970’s. even further. There are now only remnant, small substrates. Pallid sturgeon are well adapted to life on More recently hybrids have also been captured in populations of pallid sturgeon remaining in each of the the river bottom and inhabit areas of swifter water than Louisiana near the Old River Control Structure in both reservoir do the smaller shovelnose. The first documented the Mississippi and Atchafalaya rivers. Fertile hybrids complexes in natural reproduction of pallid sturgeon in the lower may constitute a serious threat to the survival of pallid North and Missouri River was recorded by U.S. Fish and Wildlife sturgeon in the southern portion of their range because South Dakota. Service biologists in 1999 and 2000 near Columbia, of competition and genetic “swamping” (i.e. shovel- Also, the MO. Several larval pallid sturgeon were collected in a nose and genes vastly outnumbering true pallid remaining side channel associated with a recently completed sturgeon genes causing them to gradually disappear riverine habitat habitat restoration project at Lisbon Bottoms on the from the gene pool). The primary forage base for adult between the Big Muddy National Fish and Wildlife Refuge. In pallids, prior to extensive modifications of riverine dams appar- October 1992 Louisiana Department of Wildlife and habitat, is assumed to have been flathead chubs, plains ently does not Fisheries biologists captured two small (24 and 26 in) minnows, and western silvery minnows which are meet the pallid sturgeon below the Old River Control Structure found over sand and gravel bars. The few pallid requirements Missouri River dams prevent up- at the headwaters of the Atchafalaya River. The sturgeon that have been held in captivity have been of the species stream pallid sturgeon movements.