Cronius ruber (Lamarck, 1818) arrives to Madeira Island: a new indication of the ongoing tropicalization of the northeastern Atlantic

Susanne Schäfer, João Monteiro, Nuno Castro, Gil Rilov, João Canning-Clode

Research output: Contribution to journalArticlepeer-review


This manuscript reports the first sightings and collection of the swimming crab Cronius ruber (Lamarck, 1818) on the coast of Madeira Island, Portugal. After the recent record in the Canary Islands, this represents a further step northward on this species’ expansion in distribution in the eastern Atlantic. The crab was first spotted during underwater visual census surveys done by scuba diving in July 2018 and was repeatedly observed during the following months, in different locations on the south coast of Madeira. Analysis of temperature data from several geographic locations where C. ruber is present was performed to assess how thermal regimes and ongoing changes may influence this recent distribution shift. Current temperature trends in Madeira suggest that the arrival and establishment of C. ruber to Madeira might have been facilitated this thermophilic species, adding evidence for the ongoing tropicalization of this area. Finally, the current spread of C. ruber in both Canaries and Madeira island systems highlights the need for a long-term monitoring program targeting this and other non-indigenous species (NIS).

Original languageEnglish
Pages (from-to)2699-2707
Number of pages9
JournalMarine Biodiversity
Issue number6
StatePublished - 1 Dec 2019
Externally publishedYes

Bibliographical note

Funding Information:
SS was supported through a federal state scholarship by the Kiel University and is currently funded by Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação (ARDITI) research fellowship in the scope of the H2020 project GoJelly. JM was supported by a post-doctoral research fellowship (ARDITI - M1420-09-5369-FSE- 000001). NC was supported by a Research fellowship for Graduates granted by ARDITI in the framework of project MIMAR (MAC/4.6.d/066) INTERREG MAC 2014-2020 Programme. JCC was supported by a starting grant in the framework of the 2014 FCT Investigator Programme (IF/01606/2014/CP1230/CT0001). Activities within this study were supported by MIMAR project cofounded by FEDER Programa (MAC/4.6.d/066, INTERREG MAC 2014-2020 Programme), Observatório Oceânico da Madeira (M1420-01-0145-FEDER-000001) and by the Smithsonian MarineGEO network. Finally, this study also had the support of Fundação para a Ciência e Tecnologia (FCT), through the strategic project UID/MAR/04292/2019 granted to MARE UI&I. This is contribution 40 from the Smithsonian’s MarineGEO Network. Acknowledgments

Publisher Copyright:
© 2019, Senckenberg Gesellschaft für Naturforschung.


  • Biogeography
  • Climate change
  • Crustacean
  • Macaronesia
  • Non-indigenous species
  • Range expansion

ASJC Scopus subject areas

  • Oceanography
  • Ecology, Evolution, Behavior and Systematics
  • Aquatic Science


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