On November 16th, 2025, a Chinese mitten crab was found in a garage entrance in Reinach, northwestern Switzerland – 1000 km upstream of the North Sea. How it got there yet remains unclear.
The adult crab was found alive and had a size of approx. 15–17 cm, including its legs. The closest river, at a distance of about 1 km, is “Birs”, a 75-kilometre-long tributary of the Rhine. Whether the crab migrated all the way from the North Sea or if it escaped from an illegal live transport or restaurant cannot be said with confidence.
Previous records in Switzerland
From catches by fishermen in the Elbe River near Dresden, it is known that mitten crabs are capable of migrating more than 700 km upstream. Chinese mitten crabs were also found in Switzerland before, but catches remain rare. Five locations are listed on the online portal “info fauna”, which is recognised by the Swiss environmental agency “BAFU” as the national data and information centre for Swiss fauna. Two are from the wider Basel area. The oldest entry dates back to 2006. Information on the origin of the crabs is not provided. To date, the cantonal fisheries inspector is only aware of individual records from the Rhine near Birsfelden.
Possible origins
The very special location where the crab was found could indicate that it was brought to Reinach by humans and did not migrate up the Birs. Live mitten crabs have a high value in the Asian cuisine. Online news magazines of the area report on a case were 17 live crabs were found in the trunk of car and then confiscated by the German border control at the Basel-Weil am Rhein motorway crossing, approximately 15 km from Reinach in October 2021. One of the online articles writes that the accused smuggler claimed to have already brought the crabs from Germany to Switzerland.
Legal context
Keeping and transport of invasive species such as the Chinese mitten crab are prohibited under EU Regulation (EU) No 1143/2014 and Implementing Regulation (EU) 2016/1141 in order to prevent the introduction and spread of such species in the EU.
Regardless how the crab got to its hideout, it was killed and disposed. From our projects point of view, preservation would have been interesting in order to find out where it came from. DNA analysis could have gifted information if the individual has travelled on its own or was released by someone.
Special thanks to Peter Sprecher for the information and the two photos.
The maps were obtained from “info fauna - CCO/KOF, swisstopo v1.4.2” and GBIF ((Eriocheir sinensis H.Milne Edwards, 1853 in GBIF Secretariat (2023). GBIF Backbone Taxonomy. Checklist dataset https://doi.org/10.15468/39omei accessed via GBIF.org on 2025-11-24)).
The image of the supermarket price tag for live Chinese mitten crabs was taken by Mirko Bögner (AWI) in Singapore in October 2025.
Article by Björn Suckow
Editing by Eline Bouckaert
Chinese mitten crab found in a garage entrance in Reinach, north-western Switzerland 1000 km upstream of the North Sea in November 2025. (c) Peter Sprecher
The crab was found alive and had a size of approx. 15–17 cm including its legs. (c) Peter Sprecher
Map from the online portal “info fauna” showing all five entries where Chinese mitten crabs were found in Switzerland since 2000 (accessed on 2025-11-24). © info fauna
Map from GBIF.org showing all georeferenced entries for Chinese mitten crabs since 2000 (accessed on 2025-11-24). © GBIF
Price for one live Chinese mitten crab (9,90 Singapore Dollar = over 6,50 €) at a supermarket in Singapore in October 2025. © Mirko Bögner (AWI)