محمود نفیسی بهابادی

Sturgeons are an interesting family of large primitive fish which are quite distinct from all other bony fish. They occur only in the northern hemisphere, and the family contains about 23 species in all of the world. The most important species of sturgeons in Iranian water bodies are Iranian sturgeon a subspecies of Russian sturgeon. Russian sturgeon, ship sturgeon, stellate sturgeon and beluga sturgeon. Sturgeons have been valued as commercial species for hundred, of years. Their large size ease of capture and tasty flesh and eggs have led to the development of important fisheries in almost all parts of the world where they occur however their slow rate of growth has rendered them very susceptible to overfishing and a number of populations have become extinct because of this. Others have disappeared due to major pollution or barriers(e. g weirs) to migration in the lower reaches of rivers which they once frequented. In Iran all of the sturgeons are endangered species and the government try to artificial propagation and restocking the species in Caspian sea. Total of 151,836,500 peaces of sturgeons released to the rivers lead to the Caspian sea from 2000 to 2010. Depleted stocks in some areas have led to successful fish farming with a number of species. The fact that several of these interbreed to produce hybrids has helped make the industry successful. In Iran because of low return of sturgeons to the rivers they once frequented, artificial culture of these species started and in year 2011 lead to 287 ton flesh and 3.6 kg caviar. The flesh is eaten fresh or smoked, and in some areas is dried. The roe is eaten as caviar. To prepare this the ovaries are removed from ripe females, the eggs are separated from ovarian tissue cleaned carefully and then packed in brine. Export of Iranian caviar about 4,000 Kg for year 2010 and the value of exported 100 million US$.