National Geographic : 1990 May
EARING the burdens of motherhood, a female Tyrannochromismacro stoma (above) guards her brood as they search for food. Juve niles are constantly threatened by predatory cichlids. At the first sign of danger she chases away an intruder (below). She then signals her young to reenter her mouth (left), where they are out of harm's way. All Lake Malawi cichlids but one are mouthbrooders. Their dramatic reproductive cycle starts when the male claims rocky territory or builds a nest in sand and begins an elaborate courtship to attract a female. Releasing her eggs one at a time, the female takes the egg into her mouth, then nuzzles the male's genital region, causing him to release sperm into the water, which the female inhales, thereby fertilizing the egg. This sequence is probably abetted by the coloration of the anal fin, which often has spots that the fe male attempts to mouth, appar ently mistaking them for eggs. The female carries the eggs in her mouth until they develop into juveniles, protecting them until they are ready to survive alone. Some cichlids feed on eggs and juveniles of others. Some species with protruding lower jaws crash into the heads of females carrying young. This forces the mothers to disgorge the broods.