A. calobrensis is not as common in the hobby as some other species in the genus (most notably A. citrinellus). It was considered a member of the genus Cichlasoma for some time, before being restored to its original position in Amphilophus. However it exhibits several characteristics that seem to set it apart from its congeners. As a result many experts believe it will probably be moved into a newly-erected genus at some point in the future. You may also see it listed as a member of Astatheros oc…

This is the type species of the genus Aequidens and has the widest distribution of any member species. It exists in various colour forms depending on locality with variants from Ecuador and Peru being particularly sought after since they develop striking red (Ecuador) or orange (Peru) colouration on the lower part of the jaw, head and anterior portion of the belly whereas those from Brazil tend to have an overall grey/blue/green colouration, for example.

Despite its type status it's long…

Described from the Maros River (Salo Maros), southwestern Sulawesi, Indonesia and subsequently recorded from rivers and streams throughout the southwestern arm of the island including Lake Tempe (Danau Tempe), plus the Mota Talau River, East Timor state on the nearby island of Timor.

More recently Herder and Chapuis (2010) reported it to be more widespread on Sulawesi, with new records pertaining to an unnamed small stre…

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 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, big enough to scare away many potential predators, or difficult to swallow. Puffers are also one of the few fish that can actually blink or close their eyes.

Many parts of the body of puffers cont…

Formerly known as Eutropiellus buffei, this midwater swimming, diurnal catfish is very often sold as "Debauwi catfish". Pareutropius debauwi is a closely related species which is, in fact, seldom imported. Adults of the two species can be distinguished by several characteristics. In buffei there are three lateral stripes along the body, whilst debauwi possesses only one. Buffei also has black spots in the upper and lower parts of the caudal fin, and the fin itself has rounded lobes. Th…

Lungfish are among the most intriguing of "oddball" aquarium subjects, being able to survive in the most extreme conditions. They are very ancient fish, having remained virtually unchanged for millions of years. Some of the natural habitats of P. dolloi are wet for only part of the year, and it has developed several incredible adaptations in order to counteract this.

When the waters begin to recede, the fish will find a suitable nesting site, usually amongst heavy vegetation. Here …

The common name of this surface-dwelling species is derived from it's appearance when viewed from above, the large pectoral fins giving it the appearance of a butterfly. In reality, these fins serve a dual purpose. They help to camouflage the fish, making it look like a dead leaf floating on the surface, and along with the caudal fin, power the incredible jumps that it is capable of making. The fish jumps from the water to catch flying insects or to escape potential predators and it can mak…

Still widely referred to as hoplosternum thoracatum the hoplo cat is a popular and hardy fish. These fish have the ability to breathe atmospheric air by gulping down mouthfuls of air and the oxygen is then absorbed into the bloodstream through the intestine. This allows the fish to endure poor conditions in the wild but it can still be observed exhibiting this behaviour in captivity.

The hoplo is also eaten as a food fish in parts of South America….