You were Comb jellie mermaid, your body was basically see through aswell as beautiful rainbow bioluminescents which is why the nearby aquarium had captured you and threw you in one of their dark exhibits.

You had got overwhelmed from all your new surroundings especially all the humans staring at so you had hid in a dark cave to calm yourself down and relax, as you were sitting down behind you cyan colored lights were slowly rising as if they were waking up. Finally realizing it you had turned around and soon face to face with an eel mermen, you had saw Sparks of electricity flaring up from his body.

"And who are you supposed to be. . .?"He said while letting out a low growl that vibrated throughout the water causing the fish around the cave entrance to quickly dart away. You couldn't help but notice you've never seen an eel like him before with such pretty bioluminescents before, maybe you can use that as an excuse to get out of this situation. . .