Golomyanka
From Wikipedia, the free encyclopedia
The Golomyanka (lit. fat fish) is a name given to two species of bullhead gobies endemic to Lake Baikal in Russia. They are the principle ecological competitor to the omul, and represent a primary food source for the Nerpa seal. They are easily identifiable, and are large enough (at 15-20 centimeters) to be easily seen. Golomyanka are unusual for their habit of moving throughout the entire water column of Lake Baikal without much regard for changes in pressure, although they can exist only within a very narrow range of temperatures and generally tend to find their ecological niche at 700-1600 feet. They are also known for rapidly decomposing in sunlight, leaving behind fat, oil, and bones.
[edit] Ecology
The biomass of the golomyanka population is estimated at anywhere from one hundred thousand to one hundred fifty thousand tons, making it one of the most populous forms of vertebrate life in Lake Baikal. They are extensively preyed upon by Nerpa, who consider the golomyanka their primary food source. Food sources for the golomyanka are fairly varied, including their own young and pelagic crayfish. Shoaling behavior is not known for this species, and the females do not lay eggs; rather, they are viviparous, producing a swarm of 2000-3000 larvae when they reach sexual maturity at two to three years.
[edit] Commercial implications
Due to their solitary lives, golomyanka are not harvested commercially, although their fats and oils were used medicinally when storms tossed them up on shore. They are valued primarily as the principle food source for the Nerpa, which are harvested commercially. They are so numerous and spawn so rapidly that they represent the largest concentration of fish biomass within the entire lake, and represent a grave threat to the ecosystem of Lake Baikal if not constantly fed upon by predators.
[edit] References
Ichthyofauna of Lake Baikal from Baikal Web World, accessed May 5, 2006.
Lake Baikal FAQ Irkutsk State University Lake Baikal FAQ, accessed May 5, 2006
Animals and plants of Lake Baikal from Irkutsk State University, accessed May 5, 2006