Despite being a wholly unsuitable aquarium subject, C. idella is often traded as such, with an albino form having been developed specifically for the ornamental market.

Individuals which have outgrown their aquarium or pond should never be released into natural waters, either, since this species has proven capable of causing serious environmental damage under a wide range of climatic conditions.

Butis spp. are largely nocturnal ambush predators with cryptic patterning to help them blend in with their surroundings. They can also lighten and darken their body colouration to an extent, have a habit of aligning themselves with solid surfaces whether horizontal, vertical, or inverted, and often swim in an upside-down position.

The genus is usually included in the family Eleotridae of which members are often referred to…

Males of this species occur in a wide range of colour forms depending on locality, with blue variants being found predominantly (but not exclusively) towards the north of the lake and yellow in the south. This variation, alongside its relatively extensive distribution, has resulted in some taxonomical issues, several of which have not yet been resolved.

For example, two forms from the southwest of the lake are referred to as A. sp. “stuartgranti maleri” and A. sp. “stuartgranti mbenji”, respectively, and may turn out to be distinct species given their colour patterns an…

This fish has been known in the aquarium hobby for a number of years but remains undescribed to science despite the confusing trade name which has resulted in it often being referred to incorrectly as ‘Aulonocara walteri’.

It’s known only from Chizumulu Island and Likoma Island in Lake Malawi, both located off the eastern shoreline of the central part of the lake (Mozambique). There is a similar-looking, potentially conspecific, fish which can be found between the coastal settlements of Meponda (Mozambique) and Ntekete (Malawi) further south, and has been referred to A. sp. ‘trematocranus masinje’.

Some eminent authors believe this species to be a geographical variant of the highly variable congener A. stuartgranti rather than a distinct taxon but since most popular resources continue to view it as valid we also list it here.

At Masinje it has been observed to show a distinct preference for rocky caves and crevices in relatively shallow (3-6 metres deep) water. This is in contrast to most other members of the genus, which tend to forage over sand, but similar to behaviour seen in A. jacobfreibergi.

This was one of the first Aulonocara spp. to enter the hobby and its popularity has endured. It’s known by several other vernacular names including ‘Freiberg’s peacock’, ‘fairy cichlid’ and ‘African butterfly’ as well as the erroneous ‘scientific’ names Trematocranus trevori, T. jacobfreigbergi and T. regina. A naturally-occurring, yellowish form from Undu reef, Tanzania is often referred to as ‘lemon jake’.

It can be told apart from most other members of the genus by the broad, pale distal margins in the dorsal, anal and caudal fins, more deeply-forked caudal fin and larger adult size.

This is currently the only described member ofthe genus and despite having a wide distribution, it's not particularly common in Lake Malawi. Correspondingly it's not seen all that often in the hobby either. It's beak-like mouthparts are specially adapted to allow it to hunt smaller fish among crevices between rocks. It can also extend the mouth in all four directions at once, allowing it to swallow prey up to around 4" long!

As well as hunting amongst rocks, Aristoch…

Described from close to the city of Beira, Mozambique and for many years thought widely-distributed between the Kruger National Park, South Africa to the Kwa-Kwa River north of the Zambezi delta.

Populations from the south and north of this range exhibiting differences in colour pattern and morphology have now been described as N. pienaari and N. krysanovi, respectively, meaning N. rachovii sensu stricto is restricted to the area between the lower Pungwe and Zambezi river basins in eastern Mozambique.