Kribensis (Pelvicachromis pulcher)
The kribensis is a dwarf west african river cichlid that is widely available in most aquarium stores worth their salt. Usually the fish sold under this name is Pelvicachromis pulcher, however some P. taeniatus have been sold under the same name. Males are about 10 cm long when fully grown, females about 5-7 cm. (Fish that are raised from fry in a tank that is too small or overpopulated will be stunted.) These fish are good aquarium fish, not aggressive unless there aren't enough hiding places, though they can be rough on other fish when they are spawning.
The name Pelvicachromis pulcher gives some idea as to the appearance of these fish: in latin it means "beautiful colourful belly". The most striking feature on these fish when they are in full breeding colour is their cherry red abdomen. The rest of the body shows yellows and iridescent blues and violets, with black and white eye spots on the dorsal and caudal fins. The kribensis can also be found under the name of Niger Cichlid, Purple Cichlid and Palette Cichlid.
One of the most exciting things about kribesis are that they form pair bonds, and are really good parents while raising their young. They take turns guarding the young, and parade them around the tank in search of food. This is also when they get aggressive, so removal of a fish that's getting picked on might be in order.
To get the most out of some kribensis there are some steps that can be taken. Firstly, one pair per 20 gallon tank with plenty of hiding spaces is just about right. To show their best colouration, dark gravel is good (if the grains are small then the kribs can dig to their hearts content and the fry won't fall between the cracks, so much the better). Provide plenty of hiding places (lots of plants is a good idea) and places to spawn (a homemade rock cave, a half a clean never-used terracotta pot or a half a coconut shell works great. Some dither fish (like rosy barbs or zebra danios) are a good idea too, because kribs are easily spooked in a bare tank and will hide for days. Dither fish are by definition small mobile fish that don't spook easily, this helps draw the shy kribensis out of hiding. Kribs can stand just about any water condition (they come from a river delta when the water can range from soft and acidic to salty and alkaline) but the water must be clean and the temperature constant at around 26 degrees Celcius. Regular water changes are necessary to keep these guys happy.
Aggression at breeding time is really the only drawback to these lovely, easy to care for aquarium fish, that, and the need to find a home for 50-300 baby kribs once every 2 months.
Sexing kribensis is easy when they're full grown and in full breeding colour, almost impossible when they're young. Contrary to some literature, eyespots and red bellies are no indication of whether a fish is male or female. It's all in the shape of the fins and the fish. Males are more torpedo shaped, and their fins taper to sharp points. Females are rounder all over, their fins resemble paddles and they have less of a "chin" than the males. If the coloured line at the top of the dorsal fin goes all the way to the end, it's most likely a male.
Some breeding behaviours that can be observed are shimmying and the U dance. Both fish can shimmy...they shiver in place, it indicates acceptance of the other fish (this feeling may not be mutual). The U-dance is when the female arches her body to one side to make her belly appear fuller to entice the male. Kribensis will also shimmy to communicate with the fry, it seems to be a sort of danger signal along the lines of "Sit down and don't move"
These are excellent beginner cichlids, and a joy to keep.
http://freshaquarium.about.com/library/profiles/blfw0096.htm
http://www.sydneycichlid.com/kribensis.html
http://www.geocities.com/Heartland/Prairie/9239/Egglayers/Kribensis.html
http://www.thekrib.com/Apisto/P-pulcher.html