The eggs of a fish, sometimes along with the membrane of the ovary that holds them, are called "roe." The word is a noun and is both singular and plural.
Fish eggs consumed by humans are typically referred to as caviar and eaten raw. The original designation of caviar applied only to roe from wild sturgeon in the Caspian and Black Sea, narrowed down even more to the specific species of Beluga, Ossetra and Sevruga. The term caviar is now accepted for other fish, including other sturgeon, salmon, whitefish, tuna and steelhead trout. The eggs are salt-cured for safety and sieved to remove extraneous tissues and membranes. Some are additionally pasteurized.