The lagoons of atoll also shelter several of the most developed families of fish:  triggerfish, trunkfish and balloonfish. These fish are characterized by specific skin (thick skin for the triggerfish, subcutaneous osseous plates for the trunkfish, thorny and toxic skin for the balloonfish) as well as very powerful teething made with welded osseous plates. These species are never very abundant, but are characteristic of the reefs. The majority are relatively large, solitary and carnivorous species. There exists however of other food modes, some species being planktivorous or omnivorous (algae, corals, invertebrates). Some species live in couples (Canthigaster spp.).