Caviar sturgeon from the Sea of Azov began reaching the tables of aristocratic and noble Byzantine Greeks in the 10th century, after the commencement of large-scale trading between the Byzantine Empire and Kievan Rus'. The main types of caviar are Beluga, Sterlet, Kaluga hybrid, American osetra, Ossetra, Siberian sturgeon and Sevruga. The rarest and costliest is from beluga sturgeon that swim in the Caspian Sea, which is bordered by Iran, Kazakhstan, Russia, Turkmenistan, and Azerbaijan. Wild caviar production was suspended in Russia between 2008 and 2011 to allow wild stocks to replenish. Azerbaijan and Iran also allow the fishing of sturgeon
USS Sterlet (SS-392) of certainty in identification forced the submarine to pass up several inviting targets. To further cloud the issue, Japanese ships probably attempted to disguise themselves as Soviets on several occasions to escape American submarines. "Sterlet", however, managed to emerge victorious over two enemy ships. In the late afternoon of 29 May, she encountered a large and a small freighter, escorted by three patrol frigates. At 16:41, the submarine tried for a good setup, but failed due to the convoy's rapid change in course. She lost sound contact around 1720 and, 40 minutes later surfaced for a daylight end-around. At 1822,