Pallid sturgeon (Scaphirhynchus albus)
Where Listed: WHEREVER FOUND
The pallid sturgeon was first recognized as a species different from shovelnose sturgeon by S. A. Forbes and R. E. Richardson in 1905 based on a study of nine specimens collected from the Mississippi River near Grafton, Illinois (Forbes and Richardson 1905). They named this new species Parascaphirhynchus albus. Later reclassification assigned it to the genus Scaphirhynchus where it has remained (Bailey and Cross 1954; Campton et al. 2000). Pallid sturgeon have a flattened shovel-shaped snout; a long, slender, and completely armored caudal peduncle (the tapered portion of the body which terminates at the tail); and lack a spiracle (small openings found on each side of the head) (Forbes and Richardson 1905). As with other sturgeon, the mouth is toothless, protrusible (capable of being extended and withdrawn from its natural position), and ventrally positioned under the head. The skeletal structure is primarily composed of cartilage rather than bone.
This species is listed wherever it is found, but
- States/US Territories in which the Pallid sturgeon, Entire is known to or is believed to occur: Arkansas , Illinois , Iowa , Kansas , Kentucky , Louisiana , Mississippi , Missouri , Montana , Nebraska , North Dakota , South Dakota , Tennessee
- US Counties in which the Pallid sturgeon, Entire is known to or is believed to occur: View All
- USFWS Refuges in which the Pallid sturgeon, Entire is known to occur:
ATCHAFALAYA NATIONAL WILDLIFE REFUGE, AUDUBON NATIONAL WILDLIFE REFUGE, BIG MUDDY NATIONAL FISH AND WILDLIFE REFUGE, CHARLES M. RUSSELL NATIONAL WILDLIFE REFUGE, DELTA NATIONAL WILDLIFE REFUGE... Show All Refuges
- Countries in which the the Pallid sturgeon, Entire is known to occur: United States
|Status||Date Listed||Lead Region||Where Listed|
|09/06/1990||Mountain-Prairie Region (Region 6)||Entire|
» Federal Register Documents
» Action Plans
|09/25/2009||Pallid sturgeon spotlight species action plan|
» RecoveryRecovery Plan Information Search
|Date||Title||Plan Action Status||Plan Status|
|03/04/2014||Final Revised Recovery Plan for the Pallid Sturgeon (Scaphirhynchus albus)||View Implementation Progress||Final Revision 1|
|Date||Citation Page||Title||Document Type|
|03/04/2014||79 FR 12213 12214||Endangered and Threatened Wildlife and Plants; Final Revised Recovery Plan for the Pallid Sturgeon, Notice of document availability|
|03/15/2013||78 FR 16526 16527||Draft Revised Recovery Plan for Pallid Sturgeon|
|06/13/2007||Pallid Sturgeon 5-Year Review|
» Critical Habitat
No critical habitat rules have been published for the Pallid sturgeon, Entire.
» Conservation Plans
No conservation plans have been created for Pallid sturgeon, Entire
|02/23/1989||54 FR 7813 7814||ETWP; 90 Day Finding on Petition to List the Pallid Sturgeon; 54 FR 7813 7814|
» Life History
Pallid sturgeon are a bottom-oriented, large river obligate fish inhabiting the Missouri and Mississippi rivers and some tributaries from Montana to Louisiana (Kallemeyn 1983). Pallid sturgeon evolved in the diverse environments of the Missouri and Mississippi river systems. Floodplains, backwaters, chutes, sloughs, islands, sandbars, and main channel waters formed the large-river ecosystem that met the habitat and life history requirements of pallid sturgeon and other native large-river fishes. Substrate Pallid sturgeon have been documented over a variety of available substrates, but are often associated with sandy and fine bottom materials (Bramblett and White 2001; Elliott et al. 2004; Gerrity 2005; Snook et al. 2002; Swigle 2003; Peters and Parham 2008; Spindler 2008). Substrate association appears to be seasonal (Kochet al. 2006a; Koch et al. 2012). During winter and spring, a mixture of sand, gravel and rock substrates are used and during the summer and fall, sand substrate is most often used (Koch et al. 2006a). In the middle Mississippi River, pallid sturgeon transition from predominantly sandy substrates to gravel during May which may be associated with spawning (Koch et al. 2012). In these river systems and others, pallid sturgeon appear to use underwater sand dunes (Bramblett 1996; Constant et al. 1997; Snook et al. 2002; Elliott et al. 2004; Jordan et al. 2006). Depths and Velocity Across their range, pallid sturgeon have been documented in waters of varying depths and velocities. Depths at collection sites range from 0.58 meter (m) to > 20 m (1.9 to > 65 feet (ft)), though there may be selection for areas at least 0.8 m (2.6 ft) deep (Bramblett and White 2001; Carlson and Pflieger 1981; Constant et al. 1997; Erickson 1992; Gerrity 2005; Jordan et al. 2006; Peters and Parham 2008; Wanner et al. 2007). Despite the wide range of depths associated with capture locations, one commonality is apparent: this species is typically found in areas where relative depths (the depth at the fish location divided by the maximum channel cross section depth expressed as a percent) exceed 75% (Constant et al. 1997; Gerrity 2005; Jordan et al. 2006; Wanner et al. 2007). Bottom water velocities associated with collection locations are generally < 1.5 m/s (4.9 ft/s) with reported averages ranging from 0.58 m/s to 0.88 m/s (1.9 ft/s to 2.9 ft/s) (Carlson and Pflieger 1981; Elliott et al. 2004; Erickson 1992; Jordan et al. 2006; Swigle 2003; Snook et al. 2002).
Data on food habits of age-0 pallid sturgeon are limited. In a hatchery environment, exogenously feeding fry (fry that have absorbed their yolk and are actively feeding) will readily consume brine shrimp suggesting zooplankton and/or small invertebrates are likely the food base for this age group. Data available for age-0 Scaphirhynchus indicate mayflies (Ephemeroptera) and midge (Chironomidae) larvae are important (Sechler et al. 2012). Juvenile and adult pallid sturgeon diets are generally composed of fish and aquatic insect larvae with a trend toward piscivory as they increase in size (Carlson and Pflieger 1981; Hoover et al. 2007; Gerrity et al. 2006; Grohs et al. 2009; Wanner 2006; French 2010). Based on the above diet data and habitat utilization by prey items, it appears that pallid sturgeon will feed over a variety of substrates (Hoover et al. 2007; Keevin et al. 2007). However, the abundance of Trichoptera in the diet suggests that harder substrates like gravel and rock material may be important feeding areas (Hoover et al. 2007).
Pallid sturgeon can be long-lived, with females reaching sexual maturity later than males (Keenlyne and Jenkins 1993). Based on wild fish, estimated age at first reproduction was 15 to 20 years for females and approximately 5 years for males (Keenlyne and Jenkins 1993). Like most fish species, water temperatures influence growth and maturity. Female hatchery-reared pallid sturgeon maintained in an artificially controlled environment (i.e., near constant 16 to 20oC temperatures) can attain sexual maturity at age 6, whereas female pallid sturgeon subject to colder winter water temperatures reached maturity around age 9 (Webb in litt., 2011). Thus, age at first reproduction likely is variable and dependent on local conditions. Females do not spawn each year (Kallemeyn 1983). Observations of wild pallid sturgeon collected as part of the conservation stocking program in the northern part of the range indicates that female spawning periodicity is 2-3 years (Rob Holm, USFWS Garrison Dam Hatchery, unpublished data). Fecundity is related to body size. The largest upper Missouri River fish can produce as many as 150,000-170,000 eggs (Keenlyne et al. 1992; Rob Holm, USFWS Garrison Dam Hatchery, unpublished data), whereas smaller bodied females in the southern extent of the range may only produce 43,000-58,000 eggs (George et al. 2012). Spawning appears to occur between March and July, with lower latitude fish spawning earlier than those in the northern portion of the range. Adult pallid sturgeon can move long distances upstream prior to spawning, and females likely are spawning at or near the apex of these movements (Bramblett and White 2001; DeLonay et al. 2009). This behavior can be associated with spawning migrations (U.S. Geological Survey (USGS) 2007; DeLonay et al. 2009). Spawning appears to occur over firm substrates, in deeper water, with relatively fast, turbulent flows, and is driven by several environmental stimuli including flow, water temperature, and day length (USGS 2007; DeLonay et al. 2009). Incubation rates are governed by and depend upon water temperature. In a hatchery environment, fertilized eggs hatch in approximately 5-7 days (Keenlyne 1995). Incubation rates may deviate slightly from this in the wild. Newly hatched larvae are predominantly pelagic, drifting in the currents for 11 to 13 days and dispersing several hundred km downstream from spawn and hatch locations (Kynard et al. 2002, 2007; Braaten et al. 2008, 2010, 2012a).
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