Russian Sturgeon (Chalbash)

The Russian sturgeon, known as Acipenser gueldenstaedti, accounts for about 70% of the sturgeon migrating to the Volga River. Its distribution is less in Iranian waters than the A. persicus or qarah-burun and its major distribution is in northern part of Caspian Sea. The muzzle of the chalbaash is shorter than the Persian sturgeon`s muzzle, the back side of it is dark and the abdomen gray and the sides are dark brown. The percentage of females is greater than males.

Males mature in nature at the age of 11 to 13, and females at the age of 12 to 16, and the average caviar production in females is 3.5 kg. In breeding environments, males and females mature at age 7 and 8 to 10, respectively, and caviar amounts to 12 to 15 percent of their body weight.

Unlike Persian sturgeon (qarah-burun), the Russian sturgeons (chalbaash) are somewhat inclined to cold temperatures and migrate to the north during the hot seasons from the southern or central parts of the sea. Their main expansion was in the northwestern part of the Caspian Sea, accounting for only about 4 percent of Iran’s catch. Its main food consists of molluscs, crustaceans, polychaetes and gobies.