The ticket options are really confusing. The "Galleries only" pass is the least expensive option and will get you into the main galleries (not the dolphin show). We were with a 2 year old, and so only had enough time between the aquarium opening and nap time to get through the main galleries anyway. In the main galleries you will see fish of all kinds, starfish, seahorses, belugas, frogs, lizards, an igauna, turtles & tortoises. More than enough entertainment for a toddler. Unless there's something in the other areas you just have to see, then don't bother with the all-exhibit pass if you'll only spend half the day.