Spottail Shiner
Spottail shiners are native to eastern North America ranging from the Mississippi basin in the west to the Atlantic seaboard, south from the gulf coast north into Canada including Hudson Bay drainages, the Mackenzie River drainage (Arctic basin), Northwest Territories and Alberta. Their preferred habitat is large lakes and rivers over a substrate of sand or gravel.  They are a shoreline species and avoid strong currents.
 
These small silvery fish, typically three to five inches, have a rather large distinctive black spot at the base of the tail.  The tail also sports a white lower edge. All the other fins are transparent.
Shiners have elongate, somewhat compressed bodies, with a well-rounded nose and a large eye.
The back is a pale olive turning silver on the sides with a white belly.
 
Spottail shiners start spawning in late spring and may spawn several times a year. They are broadcast spawners over sand and gravel near shorelines.  The eggs attach to the sand and gravel.
 
Shiners have a diverse diet with plankton, aquatic insect larvae, algae, eggs and young shiners all being on the menu.
This species is known from Arvada, Aurora, Quincy and Lon Hagler reservoirs in the South Platte drainage.