see text The Abyssocottinae are a subfamily of ray-finned fishes in the family Cottidae, the sculpins.

[2][3] These include, for instance, Abyssocottus korotneffi and Cottinella boulengeri which are among the deepest-living freshwater fish.

[5] Baikal is the deepest lake on Earth (1,642 m or 5,387 ft) and sculpins occupy even its greatest depths.

[4] Molecular studies based on mitochondrial DNA suggest that the Abyssocottinae along with other Lake Baikal cottoid fishes, now attributed to the likewise endemic Cottocomephorinae (Baikal sculpins) and Comephorinae (Baikal oilfish), together make a monophyletic group that has originated and diversified within the lake relative recently, since the Pliocene.

The Abyssocottidae itself appears as a natural group within this radiation, except that also the genus Batrachocottus should be included.