Cichlid fish building sandcastles
A type of male fish that builds ‘sandcastles’ to impress
females and intimidate rivals has provided an important clue about the
evolution of new species.
In Lake Malawi, East Africa, there are around 200 different
species of cichlid fish that once or twice a year build large sand structures
(known as bowers) on which the fish mate. Each different species constructs a
bower which is subtly different to that of other species. The males then defend
their ‘sandcastle’, hoping to attract the attention of the opposite sex.