Tetraodon is the genus that gives the pufferfish family Tetraodontidae its name, its four fused, beak-like tooth plates forming the biting edge that gives the family both its common and scientific names. Atlas species range enormously in size, from roughly 3.5 in up to around 27.5 in, and share the family's scaleless skin and reduced gill openings, along with the ability to gulp water and inflate as a defense against predators. In the atlas the genus is restricted to African freshwater and brackish systems, spanning Cameroon, the Democratic Republic of Congo, Nigeria, Angola, Burkina Faso, Chad, and Egypt - the Congo, Niger, and Nile drainages between them.
Tetraodon includes some of the best-known freshwater puffers in the hobby. Tetraodon mbu, the Mbu puffer, is the giant of the group and one of the largest freshwater puffers kept anywhere, ultimately needing a very large aquarium; Tetraodon lineatus, the Fahaka puffer, is a hardy, strikingly patterned, and notably aggressive predator popular as a solitary specimen fish; Tetraodon miurus, the potato puffer, is an ambush predator that buries itself in soft substrate to wait for prey. Like most puffers, Tetraodon species have ever-growing teeth that need hard-shelled foods such as snails to wear down, and are almost always kept alone or with very carefully chosen tankmates rather than in a community setting. Conservation status is mixed across the genus, with two Data Deficient, one Not Evaluated, two Least Concern, and one Endangered among the six atlas species.