The Baikal sturgeon, Acipenser baerii baicalensis, is a sturgeon

Sturgeon

Sturgeon is the common name used for some 26 species of fish in the family Acipenseridae, including the genera Acipenser, Huso, Scaphirhynchus and Pseudoscaphirhynchus. The term includes over 20 species commonly referred to as sturgeon and several closely related species that have distinct common...

 indigenous to Lake Baikal

Lake Baikal

Lake Baikal is the world's oldest at 30 million years old and deepest lake with an average depth of 744.4 metres.Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the...

 in Siberia

Siberia

Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...

, Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

. It is a subspecies of the widely distributed Siberian sturgeon

Siberian sturgeon

The Siberian sturgeon is a species of sturgeon in the Acipenseridae family. It is most present in all of the major Siberian river basins that drain northward into the Kara, Laptev and East Siberian seas, including the Ob, Yenisei the Lena and Kolyma rivers...

 (Acipenser baerii). It resides primarily in the northern end of the lake, making considerable movements along the shore, and migrating up the Selenga River to spawn

Spawn (biology)

Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...

. Not long ago, sturgeons weighing 125 kilograms were not uncommon. The Baikal Sturgeon is now listed as endangered

Endangered species

An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...

.