Aythya is a genus of diving ducks. The name Aythya comes from the Ancient Greek word authuia, which may have referred to a sea-dwelling duck or an auklet.

1/ Greater scaup (Vịt biển, Aythya marila), scaup in Europe, or "bluebill" in North America
The epithet marila is from the Greek word for charcoal embers or coal dust.
2/ Baer's pochard (Vịt đầu đen, Aythya baeri) 
3/ Common pochard (Vịt đầu đỏ, Aythya ferina), known simply as pochard

4/ Tufted duck or tufted pochard (Vịt mào, Aythya fuligula)
The epithet is from Latin fuligo 'soot' and gula 'throat'.

5/ Ferruginous duck (Vịt mặt trắng, Aythya nyroca), also known as ferruginous pochard, common white-eye or white-eyed pochard
The epithet is from nyrok, the Russian name for a duck.