I think it has to do with the faulty idea of evolution. You see, the fish needed fingers first because they learned how to breath air which meant they had noses.
Well, having a nose means having boogers. You've never (hopefully) picked your nose with your toes, right? No, you do it with your fingers (or in a pinch, your friend's fingers).
So some fish evolved fingers FIRST, but realized evolution was a lost cause since the apes already had the toes thing wrapped up, so went in a different path and learned how to sing and play other sea creatures as musical instruments (watch The Little Mermaid if you don't believe me).
So, since they didn't have any use for the fingers any more, they have been being released, little-by-little, to the open snack market until they run out.
Start collecting them now. When we begin to run low, you'll be a multimillionaire!