I imagine the turtle would be quite a bit harder to do than the lionfish, it can't just glide through the water it has to fly though it. The movement of the flippers would have to match its speed for it to look realistic enough to fit in with the rest of the aquarium. It would also need a completely different algorthim to define its movement, again, it can't swim like a fish. I'll be very happy to see it in a creature pack though, I have a wonderful image of it flying around in the tank now, a little baby one seems like it would fit right in.
