Tropheus moorii comes in a dazzling array of colors and color patterns. There are well over 40 different geographical variants of T. moorii, each with its own distinctive morphology. They are found in all parts of Lake Tanganyika where rocks are found, and because they are one of the easier fishes to catch, they are also well-represented in the hobby.
A sexually monomorphic species, Tropheus moorii can be quite challenging to sex. Aside from venting, however, there are few tips that might clue you in as to their gender. The upper lip of males is more prominent (i.e., larger) than that of females. Males' lips on average tend to be more off-white as well, due to their constant lip-locking aggression. Furthermore, males tend to have a turned-up nose while females tend to have a greater slope and rounded nose, making the shape of their head ellipsoid.
Males will also grow at a faster rate (generally) and display their adult colors sooner. Males' coloration is also often more bold than females' because they like to show it off when courting females. Adult males will also tend to have a deeper body, whereas females appear more slim and streamline. While these characteristics may help an experienced hobbyist, venting is the only sure way to determine gender with Tropheus.
T. moorii is strictly herbivorous like all Tropheus species. They spend the majority of their time scraping algae from the rocks in both the aquarium as well as in the wild. In fact, they are better than plecos at cleaning algae off of glass and rocks! In the wild, T. moorii are found in shallow bays and in the upper reaches of the lake over rocky reefs where the water is quite illuminated. This is because this is where the algae and other vegetable matter grow the quickest and thickest. Consequently, they are adapted to bright light.
Using extra lighting to encourage algal growth is not a bad idea - they love to graze on it; and you'll probably find they can eat it faster than it will grow. Supplementing their diet with lettuce (e.g., romaine & spinach) is highly recommended. Try feeding a leaf of lettuce each morning before feeding them flakes. And speaking of flakes...use only green flakes. These have a high concentration of Spirulina and less of wheat and fish meal. The European Shrimp Mix is a great food you can make yourself and is used by most serious Tropheus breeders and hobbyists. The only live or frozen foods that could be used to supplement their diet are Cyclops and Mysis. Avoid any soft or slimy foods, such as brine shrimp, red or white mosquito larvae, and beef heart. These foods are too easily digestable and irritate their bowels, stressing them and consequently making them more susceptible to the dreaded intestinal infection - Bloat. Foods should be rough to the touch, high in protein, and low in fat. Pellets should be soaked in tank water for several minutes before feeding.
Tropheus moorii is a very hierarchical species and should only be kept in colony proportions. They do best in groups of 12 or more. I've found that they work best when you have only two males and a dozen or so females. It is very important when setting up your colony of T. moorii to introduce them to the tank all at once. If you add fish later, it will mess up their pecking order and could throw a well established colony into chaos. This often results in unexpected deaths, either directly or from stress-induced illness.
Males are very territorial. Females, on the other hand, are not territorial unless no male is present, in which case the dominant female will assume the role of the absent male. Each male will occupy a small area in the tank. A cave or a heap of rocks is adequate, but the males will each require something with which to mark their territory.
Males are persistent and aggressive when they want to spawn. It seems that that's all they ever want to do. In fact, in an established, mature colony with at least a dozen females, spawning will be observed about every three days. Males will court females by diving in front of her, cutting her off, shaking and shimmying until she finally agrees to spawn. He will lead her to his area where they will assume the classic "T-position." They take turns circling and nudging the other's vent until the female drops and egg.
After dropping the egg, she will quickly flip around and scoop it up into her mouth. She then nudges the male's vent, at which time he fertilizes the egg. Incubation will last 24-28 days. Mouthbrooding females should be removed to another tank after 10-14 days because the male will still harass them to the point that it could over stress them. Note: Never keep more than one mouthbrooding female in a nursery tank because they will tear each other part. Continue to feed the females. They eat even though they are carrying a brood in their mouth. They will even continue to eat lettuce! Fry are of considerable size when released. They can be fed crushed flake, and after 3 months or so, they begin to show interest in lettuce. □