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Sauger
The sauger (''Sander canadensis'') is a freshwater perciform fish of the family Percidae which resembles its close relative the walleye. They are members of the largest vertebrate order, Perciformes.〔Jaeger, Matthew. 2004. Montana's Fish Species of Special Concern: Sauger. Montana Cooperative Fisheries Research Unit. http://www.fisheriessociety.org/AFSmontana/SSCpages/Sauger%20Status.htm. (Accessed May 2011).〕 They are the most migratory percid species in North America.〔Kuhn et al. 2008. Habitat Use and Movement Patterns by Adult Saugers from fall to Summer in an Unimpounded Small-River System. ''North American Journal of Fisheries Management''. 28: 360-367. American Fisheries Society. 2008.〕 Saugers obtain two dorsal fins, the first is spiny and the posterior dorsal fin is a soft-rayed fin. Their paired fins are in the thoracic position and their caudal fin is truncated which means squared off at the corners, a characteristic of the Percidae family. Another physical characteristic of Saugers are their ctenoid scales which is common in advanced fishes. Saugers have a fusiform body structure, and as a result saugers are well adapted predatory fishes and are capable of swimming into fast currents with minimal drag on their bodies. They may be distinguished from walleyes by the distinctly spotted dorsal fin, by the lack of a white splotch on the caudal fin, by the rough skin over their gill, and by their generally more brassy color, or darker (almost black) color in some regions. The average sauger in an angler's creel is in weight.
==Distribution==
Saugers are a widely distributed fish species. Their historical range consisted of eastern U.S west of the Appalachian Mountains, mostly southern, central, and western U.S up into southern Canada.〔 Sauger distribution and range has decreased from historical ranges because of degraded and fragmented habitat conditions.〔Jaeger et al. 2005. Seasonal Movements, Habitat Use, Aggregation, Exploitation, and Entrainment of Saugers in the Lower Yellowstone River: An Empirical Assessment of Factors Affecting Population Recovery. ''North American Journal of Fisheries Management ''25.1550-1568. American Fisheries Society 2005.〕 Sauger distribution within its home range varies by time of year because they are a migratory fish species.〔 Saugers are more typical of rivers whereas walleyes are more common in lakes and reservoirs. In many parts of their range, saugers are sympatric with walleyes. Hybridization between saugers and walleyes is not unknown; the hybrids, referred to as saugeyes, exhibit traits of both species. Being intermediate in appearance between the two species, saugeyes are sometimes difficult to differentiate, but they generally carry the dark blotches characteristic of the sauger. Saugers, however, are usually smaller and will better tolerate waters of higher turbidity than the walleye. Saugers require warmer summer water temperatures of 20-28 degrees Celsius. The need for warm water temperatures is thought to affect the northern and western boundaries of their range.〔Amadio et al. 2006. Abundance of Adult Saugers across the Wind River Watershed, Wyoming. ''North American Journal of Fisheries Management''. 26: 156-162. American Fisheries Society. 2006.〕
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