In Russia, they have Rusalkis, and they have Selkies in Scotland, and in Fiji, you have a special mention of it. The first earliest mermaid mentioned in history books was Atargartis in Assyria, a thousand B.C... In Africa, you have Mami Wata.
I was actually quite surprised how many more mythologies there are about mermaids than the ones our society knows. I was so pleasantly surprised for 'Siren' to add quite an original idea to that: One that is a predator. One that is very intelligent but still has to survive in the ocean with all of its challenges.
