Ossetra genitive case form "осетра" (osetra, 'of sturgeon') of the Russian word "осётр" (osyotr 'sturgeon') from the phrase "икра осетра" (ikra osetra, 'caviar of sturgeon'). At one time, the term "ossetra" simply referred to Russian sturgeon species harvested for this type of caviar. In Russian, there are different names for the species of sturgeon that live in various territories such as "Beluga" ("Huso huso"), Sevruga ("Acipenser stellatus") and Sterlet ("Acipenser ruthenus"). The name Ossetra corresponds to the species "Acipenser gueldenstaedtii", which is much smaller than Beluga sturgeon ("Huso huso"), and has a firmer texture. In the territory of the Russian Federation
USS Sterlet (SS-392) October and unleashed four torpedoes on small convoy. Results: four misses. Not to be denied, "Sterlet" made another approach on the convoy. This time, four of the six fish she launched scored. Three hit a large gasoline tanker, and the fourth plowed into a freighter. The tanker, "Jinei Maru", is known definitely to have gone down. "Sterlet" spent the remainder of the day evading the attacks of the escorts. That night, she allowed a hospital ship to pass unmolested. She attacked a small freighter with four torpedoes on 29 October, but had to surface and sink it with her deck