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
Types of motorcycles used for motor-paced cycling events. While motorcycles typically have two wheels, some motorized tricycles are classed as three-wheeled motorcycles. Some brands have made various types of three-wheelers direct from the factory. Most of these vehicles are treated as motorcycles for registration or licensing purposes. Tilting three-wheelers keep all three wheels on the ground when they lean to negotiate curves. These include Honda's Gyro range, all of which have a front wheel that leans and a pair of rear wheels that do not, and the Piaggio MP3, which has two front wheels and a single rear wheel, all of which lean.