Beluga sturgeon (esturjão Beluga, or Esturjão Branco - Latin scientific description - Huso huso), beluga coming from a Russian word belyi, ‘branco’).http://pt.wikipedia.org/wiki/Beluga
Eggs are associated with female animals, from many species. So they talk about human eggs (óvulos), fish eggs (ovas), chicken eggs/turkey/ostrich (ovos de aves), reptile eggs (examples - lizard and snake eggs - ovos de lagartixas/lagartos e cobras)http://www.wordreference.com/definition/egg
So, caviar is essentially, fish eggs (fish roe).
Caviar is a fish roe, but not always fish roe is caviar, though.https://caviarlover.com/exactly-whats-d ... -fish-roe/