Beluga

google

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late 16th century (in beluga (sense 2)): from Russian belukha (beluga (sense 1)), beluga (beluga (sense 2)), both from belyĭ ‘white’.

wiktionary

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From the Russian белу́га(belúga), from бе́лый(bélyj, “white”).

In modern standard Russian, белу́га(belúga) denotes the fish ("European sturgeon") only, while белу́ха(belúxa) denotes "white whale".

etymonline

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beluga (n.)

1590s, from Russian beluga, literally "great white," from belo- "white" (from PIE *bhel-o-, suffixed form of root *bhel- (1) "to shine, flash, burn," also "shining white") + augmentative suffix -uga. Originally the great white sturgeon, found in the Caspian and Black seas; later (1817) the popular name for the small white whale (Delphinapterus leucas) found in northern seas.