CLOWNFISHES - Here is Nemo's family (technically False Clown Anemonefishes). As with all clownfish (and most other fish, too), the largest (2-inches) is the female, the smaller one (1.5 inches) is her male mate, and the littlest (1 inch) is one of their babies.
Female 4-inch Tomato Anemonefish (aka clownfish). Female Tomato clownfish are known for being quite ornery, often swimming 6 ft or more away from their anemone to threaten would-be intruders. However, if you actually go towards the anemone, they take refuge in it like any other anemonefish would.
3-inch male Maroon (or Spine-Cheek) Anemonefish (aka Clownfish). Like male Tomato clownfishes, male Maroon/Spine-cheek clownfish are generally bright orange, and seldom venture far from their anemones.
20-25 ft whale shark. I have very mixed feelings about this practice of feeding the whale sharks; while it brings in huge amounts of money (and makes the locals protect, rather than kill, whale sharks), there were hundreds of people flailing about on the surface taking selfies, and I saw several of them actually kick the whale sharks.
A far different scenario applies to viewing Thresher Sharks near Malapascua. It is tightly controlled, with divers having to stay behind ropes in designated viewing areas. Furthermore, the Thresher Sharks aren't lured in - they come near divers as part of their natural behavior - they swim by to get "cleaned" (i.e., have parasites and dead skin picked off by butterflyfishes), so it is very much on their terms.