I am making a fish folk race, and I want to figure out if tattoos/ piercings could be possible. My ideas for piercings would be on the flesh itself or on the fins. If they had piercings in these areas, what kind of drawbacks would it have? (Note: they’re not very good swimmers, so swimming isn’t a concern. I imagine things like fins being dragged down, etc)
If done safely/hygenically, you could pierce nearly anything without organs in it. If I see your pictures, the first thing I would think is pierced gills. Very possible, but it would have a massive drawback on underwater breathing. But people have lip tunnels which have any liquid they drink pour straight out. Where there is a will, there is a way.
Of course, tattoos are completely dependent on skin composition. Set aside the effectiveness on different (darker) skin colours, if their skin is scale based then permanent paints or paints under part of the scale might be better suited than large sub-skin ones.
As for jewelry (not something you mention but often popular together with body modifications), chains and bracelets are very possible. Rings however are not due to them having webbed fingers. However these webs present another prime piercing spot.
Remember, the thinner the membrane, the easier (less painful) it is to pierce. But thin membranes are fragile, and might pose risk of tearing.
I would imagine thin but potentially large tunnels in any fins could be popular.