Fish protect themselves through color camouflage, poisonous spines, stunning shocks and chemicals. Poison injected by teeth, or through barbs or spines is a useful defense employed by catfish and scorpionfish.
Some species, such as minnows, warn others in their group when they release a chemical substance into the water. A Red Sea flounder called the Moses sole releases a chemical so effective that even sharks avoid them. Often a target for predators, the eyes of a fish are camouflaged with a black spot near the rear of the body. Predators aim for that spot rather than the head, which allows sufficient time for escape.