What is "nimbochromis"

Nimbochromis is a small genus of haplochromine cichlids mostly endemic to Lake Malawi in East Africa. They are known as sleeper cichlids or (in Chichewa) kaligono ("sleepers"), due to their unique hunting behaviour.

These piscivorous species are often seen lying motionless on the lake bottom near rocks where mbuna live, even adopting an unusual sideways position rarely seen in living fish. If smaller fishes approach, the Nimbochromis will "wake up" and try to seize them. Their coloration has an irregular dark cloudy pattern on lighter background; for one thing, this provides camouflage, but it is also suspected that it is – at least in some – evolving into aggressive mimicry by imitating a rotting fish carcass and thus luring scavengers to their demise.