I have spent hours searching for fish that will thrive in a 46gallon 3' long tank and there really isn't much Its amazing how much more fish you can have in a 4' or 5' long tank because of the swimming room. Size of my tank was a big deciding factor to go Reef because most FOWLR fish or at least the cool ones IMO need a 100g or larger tank. Granted there are some that do ok in a 75g because its 4' long I believe. I have a clownfish, 3-stripe damsel,blue devil damsel, orange spot goby,Pistol shrimp,Cleaner shrimp, fromia milleporella red starfish(may be mispelled) 2 fighting conches and 2 turbo snails, 5 astrea, and a bunch of nassarius snails-too many to count. There are other options but not many. The invertabrates and corals are the star attractions really.