Department Fish Ecology & Evolution

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.

In the Rhine, Aare, Thur and Reuss rivers, researchers caught a wide variety of fish species and fitted them with acoustic transmitters. (Photo: Jonas Steiner, Eawag)

September 21, 2026 –

When, where and why do different fish species migrate – and how successfully do they manage to do so despite the barriers posed by hydroelectric power stations? Eawag researchers are investigating this by tagging fish and tracking...

When, where and why do different fish species migrate – and how successfully do they manage to do so despite the barriers posed by hydroelectric power stations? Eawag researchers are investigating this by tagging fish and tracking their signals over a period of several years. Initial analyses have yielded surprising results.

September 18, 2026 –

This public evening lecture will take place on Wednesday 28 October at 7 pm at Eawag in Kastanienbaum. Please register in good time and make the most of the drinks reception afterwards to chat with Jakob Brodersen and other...

This public evening lecture will take place on Wednesday 28 October at 7 pm at Eawag in Kastanienbaum. Please register in good time and make the most of the drinks reception afterwards to chat with Jakob Brodersen and other interested attendees.

SRF Einstein Dokumentationsfilm über unser Forschungsprojekt "Klimawandel und Fischbewegungsmuster"

September 18, 2026 –

The SRF Einstein documentary entitled “Are we letting our fish die?”, follows a research team specialising in river fish ecology as they carry out fieldwork on the Aare, Thur, Rhein and Reuss rivers, exploring the conditions and...

The SRF Einstein documentary entitled “Are we letting our fish die?”, follows a research team specialising in river fish ecology as they carry out fieldwork on the Aare, Thur, Rhein and Reuss rivers, exploring the conditions and obstacles faced by various fish species during their natural migration through these watercourses.

In colonised countries, the profits from the exploitation of natural resources such as cotton did not benefit the countries themselves, but contributed to Europe’s industrial rise. (Photo: Martinesku, Adobe Stock)

August 19, 2026 –

A new study finds the link between biodiversity and poverty was shaped by colonial history rather than by nature itself—and argues that conservation built on the opposite assumption risks repeating it.

More News from the Department of Fish ecology and evolution

Eawag News

21.10.2026,

9.00 am

Eawag Kastanienbaum, Seeheim seminar room & Online

Changing mountains, hidden ice, and the fate of headwater biodiversity

26.10.2026,

9.00 am

Eawag Dübendorf

Angewandte Naturschutzgenetik für die Praxis

PEAK-Basiskurs B38/26

28.10.2026,

7.00 pm

Eawag Kastanienbaum, Mehrzwecksaal Seeheim

Fischen auf der Spur - Ihre Wanderungen verstehen und schützen

Ahi, E. P., Moustakas-Verho, J., & Singh, P. (2026). Ectodysplasin-A (EDA) signaling cross-talk in skeletogenesis. Calcified Tissue International, 117(1), 37 (28 pp.). doi:10.1007/s00223-026-01502-0, Institutional Repository

Ahi, E. P., Sturmbauer, C., Albertson, R. C., & Singh, P. (2026). Molecular basis of variations in facial soft tissues: insights from cichlid fishes. Developmental Biology, 529, 200-212. doi:10.1016/j.ydbio.2025.10.014, Institutional Repository

The human face serves as a crucial component of attractiveness and identity, playing a pivotal role in social interactions. Teleost fish models, particularly zebrafish, have offered valuable insights into the developmental and molecular mechanisms governing craniofacial skeletogenesis, owing to the molecular conservation in these processes. However, knowledge regarding the morphogenic processes shaping facial soft tissues remains surprisingly sparse. On the human side, most causal evidence comes from gene–phenotype associations in clinical genetics; however, these studies rarely provide cellular-resolution analyses of facial soft tissues, leaving tissue- and cell-type–specific mechanisms unresolved. The diverse family of Cichlidae constitute ∼10 % of teleost fish species and represent an exceptional opportunity for evolutionary biology research due to their extensive ecological diversity and rapid speciation rates. Cichlid fishes also exhibit remarkable craniofacial morphological diversity, making them excellent models for studying both craniofacial skeletal and soft tissue morphogenesis. Utilizing the wealth of natural mutants within cichlid populations, this short review pitches cichlid fish models as valuable tools for investigating the genetic regulators and interactions underlying facial soft tissue formation. At present, most cichlid studies rely on comparative transcriptomics between closely related species with and without pronounced traits; these data are associative, and the regulatory hierarchy and primary drivers remain to be established through functional tests (e.g., genome editing). By synthesising developmental and regulatory mechanisms that influence morphological variations in facial soft tissues in cichlids and other model organisms, we create a blueprint for future molecular genetic investigations into facial diversity. Accordingly, we highlight the need for (i) causative functional studies in cichlids and (ii) cellular-resolution analyses of human facial soft tissues to bridge correlative and mechanistic evidence across systems.