Fishes are the most diverse group of vertebrates, are key players in aquatic ecosystems, provide a diverse set of ecosystem services, and are sensitive to environmental change. We study their ecology, evolution and conservation. We work with fish diversity from traits and genes in populations to the diversity of species assemblages, their change through time and the ecosystem consequences. We are particularly interested in understanding the evolution of endemic diversity within individual ecosystems, such as the radiations of cichlid fish in African lakes and the radiation of whitefish in the lakes around the European Alps. We are a single research group led by Ole Seehausen at the University of Bern but Ole also leads the Department Fish Ecology and Evolution at the Eawag Center for Ecology, Evolution and Biogeochemistry, Kastanienbaum, where we currently host four other research groups that are all associated with the IEE too. The work of the Eawag department is motivated by the aim to contribute to the emerging synthesis between evolutionary biology and ecosystems ecology. There we also host the Swiss Fisheries Advisory Service. Researchers in the department of vertebrates at the Natural History Museum Bern, NMBE, are also affiliated with our University division.
SCIENCE - Vision using multiple distinct rod opsins in deep-sea fishes
Vertebrate vision is accomplished through light-sensitive photopigments consisting of an opsin protein bound to a chromophore. In dim light, vertebrates generally rely on a single rod opsin (RH1) for obtaining visual information. By inspecting 101 fish genomes, we found that three deep-sea teleost lineages have independently expanded their RH1 gene repertoires. Among these, the silver spinyfin (Diretmus argenteus) stands out as having the highest number of visual opsins in vertebrates expressing up to 14 RH1s, which cover the range of the residual daylight as well as the bioluminescence spectrum present in the deep sea. In addition, molecular and functional evidence for the recurrent evolution of multiple rod opsin–based vision in vertebrates is presented.