gudgeon

small spiny-finned fish of coastal or brackish waters having a large head and elongated tapering body having the ventral fins modified as a sucker

small slender European freshwater fish often used as bait by anglers

A small European freshwater fish (Gobio fluviatilis), allied to the carp. It is easily caught and often used for food and for bait. In America the killifishes or minnows are often called gudgeons.