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
Sterlet become self-sustaining. Today, the majority of the international trade involves sterlets from aquaculture. The sterlet's main source of food is benthic organisms; they commonly feed on crustaceans, worms, and insect larvae. The sterlet commonly reaches the age of 22 to 25 years. Males reach sexual maturity at 3–7 years old and females at 4–12 years old. Spawning occurs from the middle of April to the beginning of June. Females may lay from 15,000–44,000 eggs, at water temperatures preferably 12–17 °C (54–63 °F). Sterlets require relatively large ponds with good water conditions, and may get entangled in plants such as blanketweed.