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87 Rusty crayfish at moderate densities can reduce aquatic plant densities while high densities can totally eliminate plants. 141, 203 Snail numbers declined drastically (from >10,000 to <5 per square meter) in a Wisconsin lake after a Rusty crayfish invasion. 251 In the same lake, the numbers of dragonflies, damselflies, caddis flies and amphipods also declined. A similar impact was observed in Lake Erie with a 33% reduction in macroinvertebrate biomass. 223 The Bluegill and Pumpkinseed, fishes that shared prey with Rusty crayfish, declined over time while piscivorous fishes showed no change. 251 On potential positive impact was noted were Rusty crayfish reduced Zebra mussels though a similar study found no impact. 186, 223 DISTRIBUTION AND ABUNDANCE The original native range of the Rusty crayfish is considered to be an area comprising eastern Indiana, western Ohio, and central Kentucky in the Ohio drainage as well as southeast Michigan and northwest Ohio in the Lake Erie drainage. The species is often sold as bait so has been widely introduced in many areas around North America. Another source of introductions was deliberate stocking as, in the 1930's, the Ohio Division of Conservation reared crayfish in their hatcheries and provided them to private parties around the state. Most of these were probably Rusty crayfish. 233 To date, the rusty crayfish has been found four times in Nebraska. The first three were all in Douglas County. 1) The first were discovered in a bait dealer's tank in August 2005. 2) The second was in Benson Park Lagoon in 2007. 3) The third was in 2010 in the lake owned by the Lakeside Hills Association just north of 175 th and West Center Road. Based on aerial photos, this lake was built sometime between 1993 and 1999. In 1993, this area was an undeveloped pasture with a small stream and a couple of ponds. By 1999, the lake had been constructed while housing and a shopping center were under construction. By 2003 the area was pretty much as it appears now. The Rusty crayfish was first found in this lake in the spring of 2010 along with the Northern crayfish. The Northern crayfish was historically present in the drainage and mght have been present at this location. The Rusty crayfish had to have been stocked but the source is unknown. The newest find was in 2015. A South Dakota Conservation Officer found Rusty Crayfish in the possession of an angler who had collected them from the Missouri River below Gavins Point Dam (west of Yankton, South Dakota). Their presence in the Missouri River was subsequently confirmed and, as they seem to be