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
HMS Sterlet (2S) reload torpedoes for a total of a dozen torpedoes. They were also armed with a 3-inch (76 mm) deck gun. Ordered on 2 March 1936, "Sterlett" was laid down on 14 July 1936 in HM Dockyard, Chatham and was launched on 22 September 1936. The boat was completed on 6 April 1938. At the onset of the Second World War, "Sterlet" was a member of the 2nd Submarine Flotilla. From 23–26 August 1939 the 2nd Submarine Flotilla transferred to its war bases at Dundee and Blyth. On 8 April 1940 "Sterlet" left for a patrol in the Skagerrak, off Norway