This is the world smallest fish. It was on January 2006, the world smallest fish was discovered Indonesian island of Sumatra. It is a family member of the carp family, it’s scientific name is Paedocypris progenetica. More shocking is it has a backbone, when it’s only 7.9mm which is 0.3 of an inch. How small is that!
I think this shows Causation because something must have happened to this fish or to its parents to make it such a small size.