A pufferfish floating upside down in an intertidal pool in south Andaman. Puffers have an amazing defence mechanism to escape from predators. When threatened, it fills up the elastic stomach with water/air and inflates till it becomes like a spiny ball. This makes it harder for the predator to swallow a puffer. Sometimes these fishes get stuck in small pools, as they cannot make it before the tide retreats. In such situations their excellent defense mechanism acts like an oxygen tank ;)