Picture of a group of baby cichlids returning to the safety of their mouther's mouth.
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Meet cichlids: These fish are doting parents, builders, and dancers

The unique diversity of cichlids in Africa’s oldest lake could help unlock the secrets of evolution.

Baby Haplotaxodon microlepis scramble for safety in their mother’s mouth. Like many cichlid species, they’re mouth brooders: Both parents carry babies orally and let them out to feed, recalling them at the first hint of danger, until the young strike out on their own or become too big to fit.
ByNatasha Daly
Photographs byAngel Fitor
January 6, 2022
4 min read

Nothing about cichlids is ordinary. In Lake Tanganyika alone, at the divide between Central and East Africa, roughly 250 species evolved from a single ancestor over 9.7 million years. 

Some are the size of a preschooler; others, no longer than a pinkie finger. Some spend their lives searching for and defending the perfect shell or building elaborate sand stages on which to attract a mate. Others thrive in harems. Many are doting parents to their young fish—though sometimes they eat their own eggs. In a clear example of explosive diversification, cichlids (SICK-lids) have adapted to fit almost every niche in the lake. 

Picture of two emperor cichlids with hundreds to thousands of their babies swimming beneath them.
Emperor cichlids, believed to mate only once, watch over their thousands of offspring, called fry. Adults can grow to almost three feet, making them the largest of the nearly 250 cichlid species endemic to Lake Tanganyika.
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The majority of cichlids there are found nowhere else, and they offer scientists clues to unlocking the secrets of evolution. It’s an urgent endeavor: Animals are going extinct before we’ve learned how they came to exist.

The fish face myriad threats: Urban development degrades their water; gill net fishing depletes populations. The most beautiful are coveted for the aquarium trade; many die in transport.

Cichlid expert Walter Salzburger, at the University of Basel in Switzerland, hopes that growing scientific interest in the fish will spur conservation efforts. “Protecting cichlids,” he says, “means protecting the entire ecosystem of this ancient lake.”

Picture of a female cichlid emerging from a shell, her mate swims above for protection.
A female Neolamprologus brevis emerges from her home—a deserted snail shell—while her mate stands guard. ”What rules their behavior is territorialism,“ says Angel Fitor, who has been photographing cichlids in Lake Tanganyika for 20 years. To attract a mate, male cichlids first must have an empty shell—a limited commodity—for the couple to live in. Defending the shell from other males then becomes a full-time job.
Picture of two male cichlids, their jaws agape, facing off with one another.
Males fight over a shell via mouth-to-mouth combat. Fighting cichlids will lock jaws until one tires and gives up. Cichlids are constantly on alert; photographing them means spending hours immobile in the water. ”I’ve spent entire weeks just waiting in front of a shell for a fish to show up,“ Fitor says. ”It borders on insanity, I know!“
Picture of a male feather-fin cichlid dancing in a nest-like structure made of sand called a bower.
For featherfin cichlids, all the world’s a stage. This male has carried 55 pounds of sand, mouthful by mouthful, to construct a 26-inch-wide, circular bower. By morning, when he’ll shimmer in the sun, he’ll dance vigorously across his stage, hoping to attract a mate. Dozens more will do the same for passing females that judge the dances and the bowers—where couples will mate.

This story appears in the February 2022 issue of National Geographic magazine.