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of this tissue due to uncertainties of the overall effects to the fish. To date, most ages have been <br />collected from mortalities. <br />It should be noted that recent efforts to validate pallid sturgeon age estimates from pectoral fin rays <br />have questioned the accuracy and precision of this aging technique. Using hatchery raised fish, Hurley <br />(1999) documented that the majority of pallid sturgeon age estimates, based on pectoral fin rays, were <br />incorrect, with the most frequent error being 3 years. He noted a tendency to underage, rather than <br />overage pallid sturgeon samples. Large variations between first and second age estimates for the same <br />fish by each reader (within reader variation) were noted. Hurley (1999) found only 28 percent <br />accuracy and up to 4 years variation using pectoral fm rays for aging. However, a 3 to 4 year variation <br />in age estimates may not be significant given on older pallid sturgeon (40 -50 years). <br />The total length of pallid sturgeon was significantly greater than that of shovelnose in the lower Missouri <br />and Mississippi Rivers for each age group in which comparable data were available (Carlson et al. <br />1985). Fogle (1963) estimated growth rates using cross sections of pectoral fm rays from six pallid <br />sturgeon from Lake Oahe in South Dakota. He estimated that growth of those fish was relatively rapid <br />during the first 4 years, but that growth decreased to approximately 2.8 in (70 mm) per year between <br />ages 5 and 10. Carlson and Pflieger (198 1) presented data (n =8) from the Missouri and Mississippi <br />Rivers in Missouri, that showed slightly slower growth than from pallid sturgeon in South Dakota. <br />Keenlyne and Jenkins (1993) found that male pallid sturgeon showed rapid growth from age -5 to age -7 <br />until sexual maturity. Those fish were from Louisiana, Missouri and North Dakota. <br />In 1998, a 66 -1b (30 -kg), 63 -inch (160 -cm), female pallid sturgeon captured from North Dakota was <br />aged following mortality. Dennis Scameccia (1999, Univ of Idaho, pers comm.) used techniques <br />developed for white sturgeon and estimated the age at over 50 years and possibly as high as 60. <br />Movements - Pallid sturgeon exhibit seasonal variation in movement patterns based upon temperature <br />and discharge ( Bramblett 1996, Constant et al. 1997, Sheehan et al. 1998a, Hurley 1999). Movement <br />patterns also vary between spawning versus non - spawning years ( Bramblett 1996). Bramblett (1996) <br />reported an average home range of 48.8 mi (78 km) in the Yellowstone and upper Missouri Rivers <br />while Sheehan et al. (1998a) reported a home range of 21.2 mi (34 km) in the Mississippi River. <br />Sheehan et al. (1998a) speculated that because habitat in the Mississippi River is relatively uniform, <br />large movements and home ranges may not be as beneficial in the Mississippi River, as in the <br />Yellowstone and Upper Missouri Rivers area, because study fish are not likely to encounter new <br />habitats and thus have a smaller home range. <br />As large river fish, pallid sturgeon are capable of moving long distances in search of favorable habitat. <br />Sheehan et al. (1998a) noted one study fish moving along a 60.3 -mi (97 km) stretch of river. Bramblett <br />(1996) noted a maximum home range as large as 198.6 mi (319 km), with pallid sturgeon moving up to <br />13 mi/day (21 km/day) and shovehlose sturgeon moving up to 9 mi/day (15 km/day). <br />102 Status Range Wide -PS <br />