Native to the Black, Caspian or Azov Seas, Huso Huso Sturgeon have also been observed in the tributaries of the Adriatic and lonian Seas, before disappearing. It can reach a maximum length of 8m and weigh more than 1.5 tonnes. This variety of caviar is the rarest and most expensive in the world. It is characterized by grains with diameter greater than 3mm, rather oval in shape, with a colour ranging from pearl to dark grey. It takes 20 years to obtain this caviar!