Pao is a genus of freshwater and brackish pufferfish (family Tetraodontidae) from Southeast and East Asia, recorded in the atlas from Laos, Thailand, Cambodia, Vietnam, Indonesia, Myanmar, China and Malaysia. Several of its species long sat in the genus Tetraodon before being reclassified into Pao; like other freshwater puffers they have a beak-like, fused dental plate in place of individual teeth, no scales, and the ability to inflate by gulping water when threatened. The atlas covers 9 species, from about 3–7.5 in.
Freshwater puffers are a specialist corner of the hobby rather than a beginner fish — species such as Pao palembangensis (dragon puffer) and P. leiurus (brackish puffer) are kept for their intelligence and personality, but most Pao are solitary and territorial with a tendency to nip fins, so they are usually housed alone or with hardy, fast tankmates in a species-appropriate setup rather than a general community. Their ever-growing dental plate needs regular hard-shelled food — snails, shrimp, crustaceans — to stay worn down. Pao baileyi, the hairy puffer, is a hobby oddity within the genus, developing fine, hair-like dermal growths as it matures. Conservation status skews reassuring where it has been assessed — five of the nine species the atlas tracks are Least Concern — though four remain Not Evaluated.