Comephorus

Comephorus is a genus of small, freshwater fishes endemic to Lake Baikal in Siberia. These fish are notable for their unique adaptations to the deep-water environment of the lake. They belong to the family Comephoridae, which is exclusively found in Lake Baikal. The genus currently contains two recognized species, Comephorus baicalensis and Comephorus dybowskii.

Comephorus species are commonly known as baikal oilfish due to their high fat content, which can comprise up to 40% of their body weight. This high lipid content helps them maintain buoyancy in the cold, deep waters of Lake Baikal. They are also characterized by their translucent bodies, reduced fins, and lack of scales. Their skeletal structure is poorly ossified, contributing to their fragile nature.

These fish are pelagic, meaning they inhabit the open water column rather than the lakebed. They are found at depths ranging from near the surface to over 1,500 meters. Comephorus are viviparous, giving birth to live young. Their diet consists mainly of zooplankton. Despite their widespread distribution within Lake Baikal, they are considered vulnerable due to their specialized habitat and reliance on the lake's unique ecosystem.