|Scientific Name:||Sander vitreus|
|Species Authority:||(Mitchill, 1818)|
Perca vitrea Mitchill, 1818
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer(s):||Smith, K. & Darwall, W.R.T.|
|Facilitator/Compiler(s):||Hammerson, G.A. & Ormes, M.|
Listed as Least Concern in view of the large extent of occurrence, large number of subpopulations, large population size, and lack of major threats. Trend over the past 10 years or three generations is uncertain but likely relatively stable, or the species may be declining but not fast enough to qualify for any of the threatened categories under Criterion A (reduction in population size).
|Range Description:||Native to St. Lawrence-Great Lakes, Arctic, and Mississippi River basins from Quebec to Northwest Territories, and south to Alabama, Mississippi, and Arkansas; widely introduced elsewhere in U.S., including Atlantic, Gulf, and Pacific drainages; uncommon or locally common (Page and Burr 1991). Subspecies/form glaucum (blue pike) of Lake Erie, Lake Ontario, lower Niagara River, and Lake Huron (where formerly rare at most) has not been reported since 1970 and is presumed to be extinct. Native southern walleye historically occurred in all eight Mobile Basin drainages in Alabama, Georgia, and Mississippi, and in a small area of Tennessee (USFWS, Federal Register 12 September 1995).|
Native:Canada; United States
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is represented by a large number of subpopulations and locations.
Total adult population size is unknown but relatively large.
Southern walleye likely has declined in distribution and population size, but data are not adequate for an accurate assessment; USFWS concluded that the southern walleye is still sufficiently abundant that timely management and conservation efforts can improve its status (USFWS, Federal Register, 12 September 1995).
|Current Population Trend:||Stable|
|Habitat and Ecology:||Lakes; pools, backwaters, and runs of medium to large rivers; generally in moderately deep waters. Avoids bright light. Generally in quiet water when not spawning. Often in beds of aquatic vegetation, in holes among tree roots, or in or near similar cover by day. A pH of 8-9 is most suitable. Adults avoid temperatures above 24 C, if possible. Greatest population densities under moderately turbid conditions or in deep clear lakes with strong deepwater forage base (Sublette et al. 1990). See McMahon et al. (1984) for further details, including a habitat suitability index model. Spawns in turbulent rocky areas in rivers, boulder to coarse gravel shoals of lakes, along riprap on dam face of reservoirs, and flooded marshes (Becker 1983, Sublette et al. 1990). Eggs are broadcast and abandoned, adhesive but may drift great distances. Larvae initially are pelagic, soon become bottom dwellers. Adults tend to return to formerly used spawning (and feeding) areas.|
|Movement patterns:||Not a Migrant|
|Major Threat(s):||Decline of subspecies/form glaucum (blue pike) was due to degradation of Lake Erie, introduced fishes, overfishing, and hybridization with subspecies vitreum (Miller et al. 1989). Potential habitat throughout the Mobile River basin may have been affected or eliminated due to impoundment of approximately 1000 miles of river habitat and/or by extensive stream channelization and desnagging; erosion due to headcutting, a proposed channelization project, and proposed impoundments pose additional threats; potential threats to stream habitat quality include various point source effluents (e.g., coal surface mining and sand/gravel mining) as well as sediments, nutrients, and toxicants from nonpoint runoff; excessive harvest at spawning sites in Alabama may reduce reproduction; threats from dam construction, channelization, and water pollution recently may have been stabilized, but illegal gravel mining and headcutting remain problematic in some areas (USFWS, Federal Register, 13 March 1995, 12 September 1995).|
|Conservation Actions:||Currently, this species is of relatively low conservation concern and does not require significant additional protection or major management, monitoring, or research action.|
|Citation:||NatureServe. 2013. Sander vitreus. The IUCN Red List of Threatened Species 2013: e.T202605A18229159. . Downloaded on 26 November 2015.|
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