Sevruga caviar as saltier, but it can vary depending on the origin of the fish. The caviar is packaged and sold in red tins. A rare type of caviar known as Imperial Caviar, from the Sterlet sturgeon (Acipenser ruthenus), a now nearly extinct species of sturgeon from the Caspian Sea, is sometimes incorrectly labeled as Sevruga, as well as the even rarer Golden Caviar from the albino Sterlet, the caviar being yellow in color. “Pressed sevruga caviar” can also be found, made of a blend of Osetra and Sevruga caviar that has been heated in a saline solution. Sevruga caviar Sevruga caviar
USS Sterlet (SS-392) On 30 November, the submarine returned to the Submarine Base at Pearl Harbor. Following almost two months in Hawaii, "Sterlet" embarked on her third war patrol on 25 January 1945. Her assigned area was off Honshū, Japan, particularly the area off Tokyo Bay, where she stood lifeguard duty for Fifth Fleet pilots attacking Tokyo. She made reconnaissance sweeps of the Japanese Fleet and patrolled with a "wolfpack" that also included , , , and . During this cruise, she made two torpedo attacks, one each on 1 March and 5 March, and claimed two sinkings, a freighter and a tanker.