Fallfish n. : A fresh-water fish of the United States (Semotilus bullaris); -- called also silver chub, and Shiner. The name is also applied to other allied species.

Example:
What is this fish <Fallfish> just curious

Taxonomy
Fallfish, Picture, Minnow family, Northeast, abundantly, St. Lawrence River, Lawrence River basin, to Virginia, prefered habitat, swift, streams, rock pools, clear lakes, mounds, gravel, 3 feet, six feet, eggs.

Defination from the web:
Fallfish are the largest members of the Minnow family in the Northeast. Fallfish reach size typically between 12 to 18 inches long. ... The male fallfish build a mounds of gravel often as large as 3 feet high and six feet wide to protect the eggs. ...