This was a neat fish that I caught a few examples of while on my visit to southern Illinois. The Largescale Stoneroller may attain a length of 12 inches, but is usually about eight inches long. It is a dark-brown minnow with patches of brown or black scattered over the body. Its fins are short and rounded and its bluntly rounded snout projects beyond its mouth.
It is found natively in many of North American streams, rivers, lakes, and creeks. This fish inhabits well-oxygenated waters with low turbulence and a reduced flow of water. This species can tolerate waters that are polluted and therefore it does not have much competition in some habitats. It has been introduced to other areas of the United States, probably as escaped bait fish.
The Largescale Stoneroller’s lower jaw has a hard edge that is used for scraping algae when feeding. It is a herbivorous fish which eats diatoms, green algae, and blue-green bacteria, with a tendency to ingest less sand and silt than its relative the Central Stoneroller.
This creature prefers upland habitats above the Fall Line where they spawn from early March through April. Males excavate spawning pits in shallow water by moving stones with their mouths or pushing them with their heads.
It was fun to find a new fish and the Largescale Stoneroller certainly is an interesting one.