Closely related to pufferfish (family Tetraodontidae), the Rounded porcupinefish is one of the smaller of around 20 porcupinefish species (family Diodontidae), growing to only about seven or eight inches. The large eyes are well-adapted for night vision, when this species is most likely to be encountered. If threatened, this fish inflates itself by gulping water until it gradually becomes spherical in shape, completely rigid with its large, stiff spines pointed outward to prevent swallowing by potential predators. In addition to forcing the spines to point outward, the inflation of its body presents a larger appearance to help discourage predators.
Identification: Cyclichthys orbicularis