Department Fish Ecology and Evolution

Fish Ecology & Evolution (FishEc)

We study ecology, evolution and biodiversity of fishes and other aquatic organisms. We are interested in the mechanisms that drive the origins, the maintenance and the loss of species, genetic and functional diversity.


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13. September 2018
New species discovered in the Bernese Oberland
In Lakes Thun and Brienz, evolutionary biologists from Eawag and Bern University have discovered a new whitefish species. The species, provisionally named “Balchen2”, is clearly differentiated – morphologically, ecologically and genetically – from the five Lake Thun whitefish species previously described. The only lake known to harbour a higher number of whitefish species is the 200 times larger Russian Lake Onega. Read more


August 24, 2018
The Genomic Basis of Quantum Speciation in Lake Victoria Cichlids
Ole Seehausen gave this year's Wilhelmine Key Distinguished Lecture at the American Genetics Association in Hawaii. His lecture was on "The Genomic Basis of Quantum Speciation in Lake Victoria Cichlids".

The talk inspired Elizabeth Pennisi to write a wonderful story about it in Science on how "Hybrids spawned Lake Victoria's rich fish diversity".

August 17, 2018
The onset of ecological diversification 50 years after colonization of a crater lake by haplochromine cichlid fishes
Cichlids belong to one of the largest fish families, with new species emerging all the time. These colourful, shimmering fish evolve so fast that Eawag researchers have now been able to practically observe them in the process of their evolution. read more


Radio interview with Deutsche Rundfunk  

July 11, 2018
A dense linkage map of Lake Victoria cichlids improved the Pundamilia genome assembly and revealed a major QTL for sex-determination
Genetic linkage maps are essential for comparative genomics. In the present study we identified and genotyped markers via restriction-site associated DNA (RAD) sequencing and constructed a genetic linkage map based on 1,597 SNP markers of an interspecific F2 cross of two closely related Lake Victoria cichlids (Pundamilia pundamilia and P. sp. ‘red head’). This high-resolution genetic linkage map was used to anchor the scaffolds of the Pundamilia genome and estimate recombination rates along the genome. Via QTL mapping we identified a major QTL for sex in a ~1.9 Mb region on Pun-LG10, which is homologous to Oreochromis niloticus LG 23 (Ore-LG23) and includes a well-known vertebrate sexdetermination gene (amh).


Research Projects

We investigate the mechanisms of speciation and adaptive radiation
Genome evolution and genomic divergence across the Swiss Alpine whitefish radiation
Investigating the interactions between migration ecology, local adaptation and diversification