The main characteristic of these fish called sea urchin or porcupine fish is that they carry a multitude of thorns as self-defense. Therefore, they are very similar to puffer fish. Spines that only bristle when the fish is in danger.
Belonging to the Diodontidae family, they are found present in all tropical seas and some species even in temperate seas. They are larger than puffer fish. Since within the different species some that reach 90 cm in length.
Hedgehog fish like puffer fish do not have pelvic fins so it is more difficult for them to control their movements. And like these, when threatened and attacked, they triple in size. They do it by ingesting water, during this time they can barely swim or it is very slow. The spines folded up to that point bristle threateningly.
A territorial fish
El aggressive behavior in aquariums is very difficult to develop. Because the sea urchin will be subjected to the risk of a real predator. However, it must be taken into account when selecting the fish that can coexist with it without problems. Since if the spines expand, it releases a toxic substance that can endanger the marine ecosystem.
Count on a very important beak-shaped tooth when feeding. This makes it easy for it to break the shells of the invertebrates on which it feeds. For this reason they are species totally incompatible with any type of mobile invertebrate of an ornamental nature. Hence the aquarium decoration has to be made of live rock or with false invertebrates.
De sociable character adapt well to captivity and they even show some kind of appreciation for their owner. However, they may show alerts with other similar species, for example puffer fish or box fish. It will also be intolerant of its territoriality with other urchin fish.