Credit: Image courtesy of University of Bristol

 

Despite the implicit work of Charles Darwin’s work relative to theoretical studies, speciation occurs when genetic differences between groups of individuals accumulate over time. According to a recent study differences in size among fish and competition for breeding space has led to the formation of a new species.

 

An African cichlid called Telmatochromis temporalis is the subject of a new study which as determined two genetically distinct ectomorphs that strongly differ in body size and the habitat in which they live.

 

Dr Martin Genner from Bristol's School of Biological Sciences and colleagues used population genetics and experimental evidence to demonstrate a role for competition that leads to the differentiation of new species within the highly diverse cichlid fishes of Lake Tanganyika in East Africa.

 

According to the study, the bigger fish out compete the smaller ones, driving them away from the preferred rocky habitats and into the neighboring sand, where the smaller fish find shelter for themselves and their eggs in empty snail shells.

 

"In effect, big and small fish use different habitats; and because of this habitat segregation, fish usually mate with individuals of similar size. There is virtually no genetic exchange between the large- and small-bodied ectomorphs," Dr Genner commented.

 

Dr Genner said: "The relevance of our work is that it provides experimental evidence that competition for space drives differential mating in cichlid fish and, in time, leads to the formation of new species. Nature has its ways -- from body size differences to the formation of new species. And clearly, size does matters for Telmatochromis and for fish diversity."

 

From an IUCN Redlist perspective T. temporalis is classified as least concern with no know major widespread threat expect for localized sedimentation is the greatest concern for threat.

 

- see the story from ScienceDaily