“Beluga * Sterlet * Osetra * Sevruga
Caviar is the edible squishy eggs (roe) of the sturgeon, a slow-moving, bottom-grazing fish that can grow to twelve feet in length. It was originally associated with the Caspian Sea but is now bred in other regions of the world due to the fantastic price that caviar fetches and the decline in sturgeon numbers in the polluted inland sea. Beluga is the most expensive variety, composed of large, soft, pea-sized eggs (normally packed into a blue tin); Sterlet is small and golden coloured (golden tin); Osetra is medium-sized, from grey to brown (yellow or green tin); while Sevruga (red tin) are the small black and grey eggs.”
Excerpted from: Rogerson, Barnaby. Rogerson’s Book of Numbers: The Culture of Numbers–from 1,001 Nights to the Seven Wonders of the World. New York: Picador, 2013.