I have a pair of honeybees on my hipbones, specifically placed so they weren't visible unless I wanted them to be. They have a deep meaning to me, and they'll be hidden when tailed. :P

As for piercings, I have two on each lobe, a cartilage, my belly button and my 'girls'. My bellybutton would probably stay in for mermaiding just for aesthetic purposes. all the others, I suppose it depends what I'm doing. I'm looking into octopus and starfish cuffs for my cartilage, but otherwise, it's ring free for ease of swimming. Salt water is great for piercings, it solved both my belly button, cartilage and the issues with my 'girls'. TMI both my belly button and cartilage were keloiding and having issues, but then I went swimming in the ocean, and the very next day, they'd drained and were liquid free. My 'girls' were simply irritated and bothered by my work (lots of lifting and arm movement while trying to find which bra worked best, as well as sweating sue to three layers of clothes on, etc). An ocean swim and I haven't felt them since. I suppose that this isn't the most sanitary way to clean them (the ocean is dark and full of terrors!) but I live in particularly clean water, so your milage may very.