Does anyone know what fish eat if they don't have teeth? I drew a fish (As was instructed.) and gave it different adaptations. For example, my fish is dark on the top and light on the bottom- countershading. It's shaped like a torpedo and has small scales which makes it a fast swimmer. However, I don't know if it can lack teeth if it lives in a lake as the list I found online of fish adaptations has such fish eating plankton. Can plankton be found in large lakes and, if so, could a small toothless fish eat them? Oh, and another thing...if my fish is a fast swimmer, what would make more sense? It having large fins or small fins?