Each of the 12 different species of puffer fish (Tetraodontidae) is extremely poisonous -- only the golden poison frog is more deadly to predators. The only animal not intimidated by the puffed-up warning of the fish is the sharks. Known mostly for the unique way that it defends itself, the puffer fish also has an unusual method of laying its eggs.
All puffer fish reach sexual maturity at age 5. At this point, the male guides the female into shallow water, where she lays her eggs. The male does much of the work at this point, pushing the female to the proper location to ensure a safe and adequate birthing position is found. As the natural habitat for these fish is a reef, the shallow water is usually within proximity of the home "community." The male chooses a spot close to shore, yet away from potential predators.
The female puffer fish usually lays between three and seven eggs. These eggs are light enough that they float on the surface of the water, where they stay for a week until they are ready to hatch. The eggs are round with a hard outer shell. The shell cracks as the embryo inside begins to develop, and the young puffer is ready to be in the water.
As soon as the shell cracks, the juvenile puffer fish begin their final stage of growth. As they are still not fully developed until they are outside of their protective casing, the tail and fins cannot become whole, nor can the puffer fish develop teeth, spines and other essential body features. Though these develop quickly, when they hatch, juvenile puffer fish can sometimes not be seen without a magnifying glass.
Joining the Community
The young puffers are called fry, and they spend time at the surface developing before joining their parents and other community members below. After their limbs are strong enough to swim to the depths, the young fish move to the reef environment, where they complete their life cycle, potentially living for up to 10 years. Even though they start out small, some species of puffer can grow up to 2 feet in length.