Any of about 300 species (family Cottidae) of inactive, bottom-dwelling fishes found principally in northern regions. Sculpins are slender and tapered and have one or more spines on the gill covers, large fanlike pectoral fins, and smooth or spiny skin. The head is usually wide and heavy. Most species live in shallow seawaters, some live in deeper waters, and others inhabit fresh water. The largest species grow to 2 ft (60 cm) long; the miller's-thumb (Cottus gobio), common in European lakes and rivers, is only about 4 in. (10 cm) long. Other species of Cottus are found in Asia and North America.