Tetrodontoidei

a suborder of fishes of the order Tetradontiformes. The body ranges from 15 to 90 cm in length; rather than being enclosed in a bony armor, it is usually covered with spines. Owing to the presence of air sacs, the fish are capable of inflating, thus taking on the shape of a spiny sphere. The suborder comprises three families, which are found in tropical and subtropical ocean waters. There are approximately 25 genera, embracing many species. The USSR has one species, the ocellate puffer (Sphaeroides rubripes), which inhabits Petr Velikii Bay.

The Tetrodontoidei feed mainly on benthic invertebrates; some species are herbivorous. The fish spawn in the littoral zone. The females deposit 200–300 benthic roe. Some species guard their spawn. Their flesh is poisonous, containing a lethal substance called tetraodotoxin. Small species of Tetrodontoidei are raised in aquariums.