Pseudotropheus demasoni

Classification

Cichlidae

Distribution

Endemic to Lake Malawi. It occurs around Pombo Rocks off the Tanzanian coast.

Habitat

It inhabits only one rocky area, often in shallow water around the tops of the rocks. It is rarely seen in open water.

Maximum Standard Length

3″ (7.5cm).

Aquarium SizeTop ↑

48″ x 18″ x 15″ (120cm x 45cm x 37.5cm) – 200 litres as an absolute minimum, due to its aggressive nature (see below).

Maintenance

Create a network of caves and hiding places in the aquarium using piles of rockwork. This species does not require a lot of open swimming space, preferring to hug rock surfaces, so much of the aquarium should be decorated in this way. A substrate of sand is best.

Water Conditions

Temperature: 75-82°F (24-28°C)

pH: 7.6-8.8

Hardness: 10-25°H

Diet

It will accept most foods offered but vegetable matter in the form of spirulina flakes, blanched spinach, nori etc. should form a large proportion of the diet. This can be supplemented with live and frozen varieties. Never feed beefheart or any other red meat as it will interfere with the digestive system of these fish.

Behaviour and CompatibilityTop ↑

One of the most aggressive and territorial mbuna. It should not be kept with peace loving species such as Peacocks or Utaka but it can be combined with other robust mbuna, provided they do not resemble it in patterning. It has no fear and will attack fish several times it’s own size. The tank should be overcrowded to reduce aggression and territory formation. It is incredibly aggressive towards others of the same species and the presence of heterospecifics helps to dissipate this. The other option is to keep it in an overcrowded tank with many of its own kind. Subdominant males may still be eliminated, however. Several females should be kept per male in order to reduce harassment by the male. This in itself also presents problems as, unlike many mbuna females, P. demasoni are also intolerant of congeners.

Sexual Dimorphism

A difficult fish to sex, as both males and females have identical colouration and patterning. However, mature males tend to be slightly larger. The best way to sex them is by observing their behaviour, as males are more territorial and aggressive than females. Obviously, it can also be sexed by examination of the vents, but this approach is for experts only.

Reproduction

Possible. Maternal mouthbrooder. For the best results, it should be spawned in a species tank. Adult fish tend to be quite expensive, so a more feasible option is to start with a group of 6-8 young fish. A 48×15″ aquarium is an adequate size and this should be furnished as suggested above. Be sure to provide some areas of open sand and flat rock surfaces to act as potential spawning sites. The pH should be around 8.2-8.5 and the temperature 77-80°F. Condition the fish on a good diet of live, frozen and dried foods.

When in condition, the male will form a territory containing either a flat rock surface or simply an area of the substrate in which he excavates a pit. He will display around this, showing intense colour and will attempt to entice females to mate with him. He can be quite aggressive in his pursuits and it is in order to dissipate this aggression that this species should be spawned in a harem. If there are other species in the tank, they will not be permitted to enter the male’s territory. When a female is willing, she will approach the spawning site and lay her eggs there, allowing the male to fertilise them before taking them into her mouth.

The female carries the eggs for around 3 weeks before releasing the free swimming fry. She will not eat during this period and can be easily spotted by her distended mouth. If a female is overly stressed, she may spit out the brood prematurely or eat them, so care must be taken if you decide to move the fish in order to avoid fry predation. Some breeders artificially strip the fry from the mother’s mouth at the 2 week stage and raise them from that point, as this usually results in a larger number of fry. However it must be said, that this method is only for the expert.

The fry are large enough to take brine shrimp nauplii from birth. They should be watched closely as they grow and separated as needed because they display high levels of intraspecific aggression from a very young age.

NotesTop ↑

This dwarf mbuna is one of the more recent introductions into the hobby, being described only in 1994. It is not recommended for the beginner due to its pugnacious nature, but does make a good aquarium subject for the advanced aquarist. It exhibits some very entertaining behavioural traits, preferring to hug the rock surfaces much more than most mbuna. It will often be seen swimming on its side or upside down as it explores caves and crevices. As with other members of the genus, it possesses flat, bicuspid teeth which are designed for scraping algae and other organisms from the surface of rocks