This is a very special merboy, the first tropical fish in space! Here he is floating in a SpaceX dragon capsule wearing a modified starman suit that accommodates his tail. He's loving the mission, even though he's having a little trouble getting around in zero-g.
Animated GIF available for my Patrons.

I'd like to put it to SpaceX to take a mermaid tail up to the ISS so we can test out how merfolk would cope in zero-g. ;)

Arkuatica comic, anyone? https://www.patreon.com/Arkuatica
https://www.patreon.com/DonPretzel