Cichlids of the Rift Lakes; Evolution; Exclusive Online Issues; by Melanie L. J. Stiassny and Axel Meyer; 6 Page(s)

The waters of Lake Tanganyika are clear, dark and deep, but the shallow, sunlit edges are where most of the cichlids live. Brown or green Eretmodus algae scrapers, covered with blue spots, thrive among the breaking waves; the turbulent water pushes their rounded backs onto the rock surfaces instead of pulling them off. These fish nip algae off the rocks with their chisel-like teeth. Their neighbors the Tanganicodus insect pickers also have round backs. But the pointed heads, sharp snouts and long, fine teeth of these cichlids are adapted to plucking insect larvae from within the crevices.

In calmer waters, old snail shells are strewn on sandy shelves between the boulders. Inside these live tiny female Lamprologus cichlids, along with their eggs and young. The yellow, green or brown males are too large to enter the abode. Instead they steal shells-sometimes with females inside-from one another, and posture and preen around their harems.