The haps (they were formerly included in Haplochromis) can be further subdivided into three subgroups: The relatively large, often more than 20 cms long, and aggressive piscivores that roam various habitats in pursuit of prey, the open-water (although often not far from sand or rocks) utaka that feed in schools on zooplankton and typically are of medium size, and finally a subgroup of "aberrant" species that essentially are defined by them not fitting clearly into the other subgroups.