Puffer fish are so called as they have the ability to inflate their elastic stomachs with water or air. This is usually a response to some kind of threat, although in the aquarium many specimens appear to inflate themselves for no apparent reason. The fish becomes 2 or 3 times its normal size, big enough to scare away many potential predators, or difficult to swallow.

Puffers also have several other interesting adaptations. They are one of the few fish that can actually blink or close their …

Puffer fish are so called as they have the ability to inflate their elastic stomachs with water or air. This is usually a response to some kind of threat, although in the aquarium many specimens appear to inflate themselves for no apparent reason. The fish becomes 2 or 3 times it's normal size, which makes the fish both big enough to scare away many potential predators, and difficult to swallow.

Many parts of the body of puffers contain the deadly neurotoxin tetrodoxin. This is the same …

This species is also referred to as ‘South American puffer’, ‘SAP’, ‘Amazonian puffer’, ‘Peruvian puffer’, or ‘Brazilian puffer’ in the ornamental trade.

Within the genus Colomesus, C. asellus can be immediately identified by possessing a unique transverse row of dermal flaps across the chin which is absent in its congeners C. psittacus and C. tocantinensis.

This species is uncommon in the aquarium hobby. It is similar to the congeners C. borneensis and C. lorteti but can be told apart by males possessing a red (vs. bluish to greyish with black and white distal bands in C. lorteti) caudal-fin and lacking (vs. possessing) a black blotch at the base of the dorsal-fin.

For many years, this species was included in the genus Telmatherina, and is still listed as such in much of the avilable literature. In fact it's now the only species in the recently erected genus Marosatherina. Unfortunately, it has been overfished for the aquarium trade in its native waters and is listed as 'vulnerable' on the IUCN red list of threatened species. Thankfully, it's now being mass-produced on fish farms in both the Far East and Eastern Europe, meaning that few…

Known from the lower Mekong basin in Thailand, Vietnam, and Cambodia, the Chao Phraya watershed in central Thailand, and may occur in smaller river systems between.

Type locality is ‘Thu-dâu-môt, Vietnam’.

An incredibly hardy species, M. albus has the ability to travel over land for short distances if kept moist and as mentioned above, often burrows into moist earth (sometimes up to a depth of 1.5 metres!) in order to survive dry conditions. It has only a single gill slit, located on the bottom of the throat, that allows it to trap air in its specially adapted gills. These contain an accessory breathing organ, which takes the form of a pair of lung-like sacs at the rear of the gill chamber. In thi…

This species is clearly not an aquarium fish, and thankfully is not imported with any great regularity. Young specimens are occasionally seen for sale however and no matter how cute they look, don't be tempted to buy one. The gigantic adult size is not the only problem with W. attu, as the mouth is filled with needle sharp, backward-pointing teeth. The fish will bite aggressively when being fed, especially when handled and larger individuals could easily sever a hand or worse. It is a genu…

Not often encountered in the hobby, but makes an ideal schooling catfish for a community of medium to large peaceful fish.

This infrequently seen (in the trade) species is also known as the two spot glass catfish, for fairly obvious reasons. It is more than likely that a number of separate species are currently considered within this one, as there are clear morphological differences between populations. Pending a taxonomic revision, these currently all remain classified as O.bimaculatus. This would also seem to explain the apparent toleration of the fish to wildly different water chemistry. Xanthic and albino forms …