The explosive speciation and adaptive radiation of haplochromine cichl
id fishes in Lake Victoria is unrivalled among vertebrates. It holds a
nswers to many intriguing questions about the origins and maintenance
of biological diversity. Unfortunately, Lake Victoria is also a case-s
tudy in anthropogenic mass extinction. Over 50 per cent of its endemic
fishes disappeared between 1980 and 1986. Hundreds of species abruptl
y became extinct or vanished, disappearing an order of magnitude faste
r than they could be described. This article examines the dynamics tha
t underlie this fauna's extraordinary volatility, and hence points the
way towards its conservation.