SciFi and Fantasy Art: (3) Coy

I've always found mermaids to be a difficult subect to draw mainly because there's no clear-cut description of what a mermaid is. Over the last couple of months all sorts of mermaids have been swimming through my head: some with goldfish tails, others with dolphin tails, even ones with eel-like tales. There was one odd thing I noticed. All the air breathing Mers had their tails horizontally splayed (like dolphins and whales) while the non-air breathing ones had their tails splayed vertically (sharks, salmons and such)... so... just how varied are the races/species of mermaids?

This one managed to swim out of my ear and landed on the paper. Hopefully she stays on the paper a little while longer cause she might be swimming on someone's back sometime soon.

2B mechanical pencil on A4 80gsm paper.