Tuesday, September 04, 2007

The underwater mystery of an African lake


Strange things happen in Lake Malawi, in central Africa. The waters teem with many species of cichlid fish, whose mysterious courtship rituals baffle zoologists.

In some types of cichlid, each male builds a bower or egg-mound in the sand, which he hopes will so impress a female that she will lay her eggs above it. These bowers vary in height from about 1.5 in (40 mm) to 6 in (15 cm) or more, some being splendid 'sandcastles' 10 ft (3 m) across. Yet others may be crater-shaped, flat-topped or just a scrape in the sand.

Males of the same species build their bowers close together in one of the areas where courtship displays take place. This enables interested females to inspect all the bowers and select a mate.

What makes a female cichlid choose one male above all others, is still a mystery. There is no discernible pattern of behaviour, and what determines a male's success remains unknown.

1 comment:

Lewis Empire said...

Maybe the piles of sand to these fish are like clothing to people. To an observer, there may be no rational explanation how both a business suit and a fire-fighter's uniform can attract mates but somehow they do!

Perhaps some of the fish like large craters and some like tall towers. The observers are assuming that all the fish should act and think the same. People can barely figure each other out!