What people would say is: "What kind of fish do you keep in your fish tank?" "Oh, well, I actually have more (animals) than just fish in there." "Oh really?

What people would say is: "What kind of fish do you keep in your fish tank?" "Oh, well, I actually have more (animals) than just fish in there." "Oh really? What else (what "other animals") do you have? "Turtles and frogs."