Pufferfishes and Their Relatives

an illustration of pufferfish species and their relatives
(Smithsonian Institution)

Pufferfishes and their relatives are some of the most diverse fishes in terms of their anatomy and natural history. They range in size from less than an inch long (2.5 cm) to some of the largest fishes in the ocean that can weigh more than 6,000 lbs (2,721 kg) and reach 10 ft (3 m) in length. They can be drab or colorful and some species can rapidly change color. Many also have interesting scales, spines, or other antipredator adaptations such as inflating their stomach with water to increase body size, being covered with stiff, inflexible armored plates, or having powerful toxins.