The Greater Redhorse is the largest redhorse in the world. It can reach weights approaching 17 pounds. Greaters have become very rare in recent years, mostly due to habitat degradation, the building of migration-blocking dams, and the decline in clam populations in our major rivers. These fish often dine on clams, crushing them with the molarlike teeth at the back of their throat. The Greater has a fan-shaped, bright red top fin, 8 scales across the base of the tail, and a rounded top lobe of the tail fin. Good baits for greaters are nightcrawlers, crawfish, and shrimp. Flies for greaters include most crawfish and stonefly imitations, as well as clam flies. Their fight is incredible. This is truly the fish of a lifetime.

photo courtesy of Vinnie 

Identification

The greater redhorse has a bright red tail and a convex (fan-shaped) dorsal fin.  Coloration is dark - each scale has a dark patch at the base.  Greaters have a large mouth.  Greaters are most often confused with the River Redhorse.  Rivers can be distinguished by their concave dorsal fin, or by counting the scales across the base of the tail in a diagonal line.   Rivers have six scales along this line, while Greaters have 8.

photo courtesy of Jknuth 

Spawning

The greater redhorse begins spawning at a water temperature of approximately 64 degrees.  This usually occurs around the end of May in the midwest. It spawns in riffles from 2-4 feet in depth, covered with sand and gravel.