Why are there so many varieties of Cichlid
The cichlids of Lake Malawi are often referred to as a biological miracle.
“All cichlid species in the lake have evolved from a common ancestor. The reason of having these hundreds of species now is a phenomenon called runaway sexual selection that got out of hand”, Ken McKaye explains.
New colours may lead to new species
Among Lake Malawi cichlids, the females choose their males and take care of the offspring. All the males need to do is to look good.
If a mutation produces a male with a new colour, and if there is a female that likes this colour, these fish become isolated from their own species and effectively form a new species (which is defined by the ability to interbreed).
Their offspring may have the same colour as the males. A new species could, theoretically, emerge in a single generation, but in reality it often takes longer than this.
A puzzling variety of feeding behaviours
Another question keeps puzzling the outsider.
Why are there so many different feeding behaviours? Having such varied behaviour in one family is unusual.
In most families, animals all do the same thing. For example, all cats in the family Felidae, are predators that hunt for food. Compared to other animals, cichlids seem to have quite a flexible morphology and neural system, while there is substantial variation in cichlid behaviour in other parts of the world, too.
Flexibility an asset to survive
In Lake Malawi, with its rare explosion of hundreds of species, this flexibility has become more necessary than anywhere else.
With so many other species competing for food, it is a huge advantage to develop a diet or a feeding strategy used by no other species.
Natural selection has thus strongly favoured any novel way of feeding, no matter how strange.
“All cichlid species in the lake have evolved from a common ancestor. The reason of having these hundreds of species now is a phenomenon called runaway sexual selection that got out of hand”, Ken McKaye explains.
New colours may lead to new species
Among Lake Malawi cichlids, the females choose their males and take care of the offspring. All the males need to do is to look good.
If a mutation produces a male with a new colour, and if there is a female that likes this colour, these fish become isolated from their own species and effectively form a new species (which is defined by the ability to interbreed).
Their offspring may have the same colour as the males. A new species could, theoretically, emerge in a single generation, but in reality it often takes longer than this.
A puzzling variety of feeding behaviours
Another question keeps puzzling the outsider.
Why are there so many different feeding behaviours? Having such varied behaviour in one family is unusual.
In most families, animals all do the same thing. For example, all cats in the family Felidae, are predators that hunt for food. Compared to other animals, cichlids seem to have quite a flexible morphology and neural system, while there is substantial variation in cichlid behaviour in other parts of the world, too.
Flexibility an asset to survive
In Lake Malawi, with its rare explosion of hundreds of species, this flexibility has become more necessary than anywhere else.
With so many other species competing for food, it is a huge advantage to develop a diet or a feeding strategy used by no other species.
Natural selection has thus strongly favoured any novel way of feeding, no matter how strange.
