Every species

V. moorii exists in several geographical morphs but interestingly the only variation in colour occurs in juvenile fish. All adults exhibit a dark patterning but depending on locality the fry may be dark (like adults), yellow or orange with the yellow and orange juveniles taking on the adult colouration as they mature. It is has been observed that the forms which undergo this colour change may 'plant' broods among fry of other species with similarly coloured young, leaving them to be gu...

A strikingly coloured, if somewhat aggressive fish. Also referred to as the White Cichlid, it is occasionally available in the UK through specialist cichlid dealers.

Vieja bifasciata are often confused for vieja synspilum but can be told apart as bifasciata have two prominent horizontal lines running between their eyes (hence the name). They are a very colourful fish and respond to their owner's presence - usually looking for food! Bifasciata are not particularly demanding in terms of water parameters and easy to keep, especially if suitable tankmates can be found. It is sometimes the case that a pair of fish that will not live together in a tank on ...

A very attractive fish when in adult colouration, vieja fenestrata is not all that common in the UK hobby. It can is often confused with the more commonly available v. synspila.

The Blackbelt Cichlid gets its name from two things: firstly the vertical black stripe around its flank, and secondly its toughness. Vieja maculicauda is a tough, aggressive fish and should be respected as such. Maculicauda is a relatively easy fish to keep. They are not impossible to breed, but not the easiest fish either. If you seriously intend to breed this fish, it is a wise decision to house 6 juvenile fish in a large tank (212 litres at least), and let them pair off. When a pair has be...

An attractive, if uncommonly seen cichlid. In common with many Central American cichlids, these fish can pose in a challenge in terms of accomodation and it not uncommon to end up having to house these fish individually. Previously described as cichlasoma regani, it is still occasionally sold under this name.

Widely and incorrectly referred to as vieja synspillum, this colourful fish is the most commonly available of the vieja species to the hobby. Although not as aggressive as some of its family, it is still a fish to treat carefully. It can be found in mildly brackish waters in its natural range but this is not recommended or required in captivity....

A hardy and easy to keep cichlid, albeit a moderately aggressive one. Rarely available in aquatic stores, this fish is occasionally available through specialist cichlid dealers.

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...

Wallago are fearsome predatory catfish that are fairly widespread in southeast Asia. There are currently five recognised species, W. attu, W. leerii, W. hexanema, W. maculatus and W. micropogon. The latter was described to science in 2004 by renowned catfish expert Heok Hee Ng and was previously considered to be a geographic variant of W. leerii. All members of the genus possess an enormous mouth full of backward pointing teeth, which are used to rip chunks from their prey. Smaller fish or amphi...

X. cancila is often seen referred to as 'freshwater garfish', and although it does superficially resemble the true gars of the family Lepisosteidae, it's actually a member of the Belonidae, or needlefishes, the majority of which are marine or estuarine in existence. There are currently just two species in the genus although the probable existence of a third member has been noted by Roberts (1989) among oth...

This species is a near-exclusive inhabitant of the upper water column and appreciates surface cover in the form of floating or overhanging vegetation. Other décor is relatively unimportant but can consist of a sandy substrate with leaf litter plus some large driftwood branches and twisted roots. Plants which can grow rooted in sand can al...

Originally classified in the genus Notopterus and reclassified in 1984, this is now the only described species of Xenomystus and has several interesting characteristics. Its swim bladder is specially adapted to act as an accessory breathing organ in a similar fashion to Polypteriids. It must rise to the surface to take a gulp of air periodically, often emitting a bell-like sound as it does so. X. nigri is often confused with the similar looking but far more aggressive Asian knifefish, Notopt...

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 though 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 become 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 contai...

In nature, the pair bond formed by this species lasts only for the duration of the breeding season. However, in aquaria this bond can last much longer, with the pair remaining in their territory and defending it even when not spawning. It is thought that this is directly due to the fish being kept in the confines of the aquarium, where the territory is a permanent fixture. X. flavipinnis is very sensitive to deteriorating water conditions and regular water changes are essential to its good heal...

This fish feeds in a similar way to Geophagus species in that it will sift sand through its gills to extract invertebrates and morsels hidden in the substrate. It was until recently classified in the genus Enatiopus and is still named as such in much of the available literature. There are slight geographical variations in colour but these are not major. Interestingly, the shoals in which these fish live in nature appear to be fixed. That is, that an individual will remain in the same group for ...

A rarely seen species in the hobby, X. sima is nevertheless a charming species for the peaceful Tanganyikan community. It feeds in a similar way to the well-known South American Geophagus species in that it will sift sand through its gills to extract invertebrates and morsels hidden in the substrate. It is quite a skittish fish and may react very nervously to rapid movements outside the tank or when lights are switched on and off....

An incredibly hardy and adaptable species that is not so popular in the hobby as it once was, probably due to its often aggressive nature. As with other goodeids, there is less of a size difference between the sexes than in many other livebearers. This is thought to be related to the relatively primitive structure of the andropodium, as the fish tend to choose mates that are of similar size so that the sex organs are synchronised. Goodeids are unique among livebearers in that the developi...

Wild swordtails are a fairly basic green colur. However the vast majority of swordtails available in the hobby today are hybrids of X.helleri with X.maculatus or X.variatus. There are a huge number of selectively-bred varieties available, including wagtail, lyretail, tuxedo, albino, neon, red, green and hi-fin. Swordtails may undergo what appears to be a change in sex. In young fish this may simply be late development. However some adult females develop male characteristics which is thought ...

Another massively popular aquarium fish, with dozens of selectively bred varieties available, including mickey mouse, wagtail, tuxedo, moon, blue, red, comet and hi-fin. Some of these are produced by crossbreeding with X.helleri or X. variatus. Unfortunately many commercially bred platies are not very hardy due to inbreeding and over-production and are prone to disease and premature death. Wild fish are almost never seen in the hobby. As long as the ph remains above neutral this fish is ...