NOTHING ABOUT CICHLIDS is ordi-

nary. In Lake Tan ganyika 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 preschool -

er; 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 par-

ents 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. 

The majority of cichlids there are found nowhere else, and

they offer scientists clues to unlocking the secrets of evolu-

tion. 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.” j

AFRICA

Lake

Tanganyika

N

NGM MAPS