Violet Goby-I'd recognize that face anywhere!
Location fits the species, as does the face, tiny eyes, and that long dorsal fin and eel like length. I have heard of them reaching 24" in captivity. I've owned a 12" specimen that I gave up due to habitat decisions-needs to be brackish. And yes, purple tinted.
Walks like a duck, and quacks like a duck, probably a duck...