Caviar off their coasts. Beluga caviar is prized for its soft, extremely large (pea-size) eggs. It can range in color from pale silver-gray to black. It is followed by the small golden sterlet caviar which is rare and was once reserved for Russian, Iranian and Austrian royalty. Next in quality is the medium-sized, light brown to rich brown Ossetra, also known as Russian caviar. Others in the quality ranking are the gray sevruga caviar, the Chinese Kaluga caviar, and the American osetra. The Siberian variety with black beads is similar to sevruga and is popular because of its reduced (5 years)
Hypothetical types of biochemistry Hypothetical types of biochemistry Hypothetical types of biochemistry are forms of biochemistry speculated to be scientifically viable but not proven to exist at this time. The kinds of living organisms currently known on Earth all use carbon compounds for basic structural and metabolic functions, water as a solvent, and DNA or RNA to define and control their form. If life exists on other planets or moons, it may be chemically similar; it is also possible that there are organisms with quite different chemistries—for instance, involving other classes of carbon compounds, compounds of another element, or another solvent in place of