Comephorus

Genus of fishes

Comephorus, known as the golomyankas or Baikal oilfish, are a genus comprising two species of peculiar, sculpin fishes endemic to Lake Baikal in Russia. Comephorus is the only genus in the subfamily Comephorinae. Golomyankas are pelagic fishes and the main food source for the Baikal seal.

Comephorus was first proposed as a monospecific genus in 1800 by the French naturalist and politician Bernard Germain de Lacépède with Callionymus baikalensis as its only species. Other authorities have used phylogenetic studies which have found that Baikal sculpins that were classified in the subfamilies Comephorinae and Abyssocottinae by Fishes of the World radiated from an ancestor which was likely to be within the genus Cottus and that the classification of the Baikal sculpins in a different taxon from Cottus was paraphyletic.

The common name golomyanka originates from the old Russian golomen, meaning "far from the shore" in the local dialect and referring to their pelagic behavior. They are the principal ecological competitor to the omul, which also eat small golomyankas, and represent a primary food source for the Baikal seal, at more than 90% of its diet. During the night they move up the water column to feed, often occurring as shallow as , and in the winter they can occasionally be seen swimming just below the ice covered surface. They are considered the world's most abyssal freshwater fish, together with certain Lake Baikal deep water sculpins (Abyssocottidae). They move without much regard for changes in pressure, although they can exist only in cold temperatures, preferring water that is no more than 5 °C (41 °F) and dying at 10 °C (50 °F). The biomass of the golomyanka population is estimated at about 150 thousand tons, making it the most populous fish in Lake Baikal. Large shoals are not known for this species, although groups of up to about 20 individuals have been recorded near the lake bottom. and have relatively large mouths with several rows of somewhat brush like teeth, allowing them to sift out fine organisms from the water. including those of their own species.

Despite being numerous in the lake, golomyankas are difficult to catch in large quantities as they do not gather in large schools. Golomyankas are not harvested commercially, although their fats and oils were used in lamps and as traditional medicine by native Siberians when storms tossed the fish up on shore. They are of no value as a food source for humans, dogs or cats, but are the primary food source for the Baikal seal, and also eaten by other fish in the lake. They are so numerous and spawn so rapidly that they represent the largest concentration of fish biomass within the entire lake, and would seriously unbalance the ecosystem of Lake Baikal if not constantly preyed upon by predators.