here is somemore info i found that may help also.
The common krib, Pelviachromis pulcher
is a territorial fish and typical of the genus in most respects. The males are somewhat longer and thinner than the females. Females are quite rotund, and are marked with a plum coloured patch around the belly. Males may also have a series of "eye spots" on the upper part of the tail fin, but not always. They settle down quickly in a community tank, if provided with a lair of some sort (half a coconut shell, or a flower pot, make fine substitutes for the rocky overhangs they use in the wild). There is usually little problem in identifying matched pairs, as they couple will actively burrow in front of the lair. If you have other kribs in with them, especially males, it is best to remove them.