How fish got their spines

In the movie "A Fish Called Wanda," the villain Otto effortlessly gobbles up all the occupants of Ken`s fish tank. Reality, however, is more daunting. At least one unfortunate fan who re-enacted this scene was hospitalized with a fish stuck in the throat. This was also was a painful lesson in ichthyology (the scientific study of fishes)—namely that the defense of some fishes consists of needle-sharp fin spines.