[2] Species occupy many types of aquatic habitats, including marine and fresh waters, and deep and shallow zones.

A large number occur in near-shore marine habitat types, such as kelp forests and shallow reefs.

[3] The Cottidae was first recognised as a taxonomic grouping by the French zoologist Charles Lucien Bonaparte in 1831.

The 5th edition of Fishes of the World retains a rather conservative classification, although it includes the families Comephoridae and Abbyssocottidae as subfamilies of the Cottidae recognising that these taxa are very closely related to some of the freshwater sculpins in the genus Cottus.

[4] Other workers have found that Cottidae is largely restricted to the freshwater sculpins, i.e. Cottus, Leptocottus, Mesocottus, Trachidermus, and the species flock in and around Lake Baikal, and the marine genera are placed in the Psychrolutidae.