Like Sea Bream, there are many different Emperor species. 

They look a lot like Snapper, and are closely related, the difference being that Emperor are species from the family Lethrinidae and Snapper are from the family Lutjanidae. 

Just to further confuse, there is a fish called Emperor Snapper that is a member of the Lutjanidae family. 

Ranging from 300g– 1kg, varieties of emperor include Longnose, Emperor Snubnose, Spangled (also known as Capitaine or Blue Emperor) and Yellowtail Emperor (Lethrinus atkinsoni). 

When it comes to cooking, while Emperor does not have quite as strong a flavour as Snapper, it can be cooked in the same way.