What are Marmorkrebs?
“Marmorkrebs” is an informal name given to marbled crayfish that were discovered by hobbyists in Germany in the late 1990s.
Marmorkrebs are parthenogenetic: they are all females, and reproduce without sex. This is the only decapod crustacean found that reproduces only this way, giving it incredible potential as a model organism for research. Some of the advantages of Marmorkrebs are that they are genetically identical, reproduce at high rates, and are easy to care for.
“Marmorkrebs” roughly translates from German as “marbled crab.” The scientific name for Marmorkrebs is Procambarus fallax f. virginalis or Procambarus virginalis; they are an asexual relative of slough crayfish (P. fallax) that live across Florida and southern Georgia in the United States. There are no known native populations of Marmorkrebs in North America; the only known cases of them in the wild are where they have been introduced by humans.
Marmorkrebs are also an invasive species. They have been introducted in many places, and have established populations in at least three countries, damaging agriculture and threatening native species. Marmorkrebs should not be used for bait (see here), kept in outdoor tanks or ponds (Marmorkrebs can migrate over land; see here), or placed in any other situation where they could be released into natural ecosystems. In North America, Marmorkrebs are prohibited in Missouri (since 2011) and Tennessee (since 2015). The European Union banned possession, trade, transport, production, and release of Marmorkrebs (and several other crayfish species) in 2016.
View Marmorkrebs introductions in a larger map
Marmorkrebs blog. Award-winning science writing! Updates roughly weekly, usually Tuesday.
Colonies and stocks
North American researchers can contact Zen Faulkes to get Marmorkrebs for research. Establishment of the Faulkes lab Marmorkrebs colony was supported by the National Science Foundation (award 0813581).
2017 research papers
Chucholl C, Wendler F. 2017. Positive selection of beautiful invaders: long-term persistence and bio-invasion risk of freshwater crayfish in the pet trade. Biological Invasions 19(1): 197-208. http://dx.doi.org/10.1007/s10530-016-1272-5
Koutnik D, Stara A, Zuskova E, Kouba A, Velisek J. 2017. The chronic effects of terbuthylazine-2-hydroxy on early life stages of marbled crayfish (Procambarus fallax f. virginalis). Pesticide Biochemistry and Physiology 136: 29-33. http://dx.doi.org/10.1016/j.pestbp.2016.08.008
For more research papers, click here.
Anonymous. 2007. British crayfish could be wiped out by alien species with the plague. The Daily Mail. 28 June 2007.
Anonymous. 2016. Cangrejo mármol, una curiosa especie invasora con dos caras. Real Jardín Botánico press release. 8 September 2016. http://www.rjb.csic.es/jardinbotanico/jardin/contenido.php?Pag=236&tipo=noticia&cod=5283
Coghlan A. 2003. Crayfish clones poised to invade European waters. New Scientist 2383 (22 February 2003).
Faulkes Z. 2009. How Marmorkrebs can make the world a better place. In: Rohn J (ed.), Grant RP (deputy ed.), Zivkovic B (series ed.), The Open Laboratory: The Best In Science Writing On Blogs 2008, pp. 86-87. Coturnix: Chapel Hill.
Faulkes Z. 2011. The decade the clones came. In: Goldman JG (ed.), Zivkovic B (series ed.), The Open Laboratory: The Best of Science Writing on the Web 2010, pp. 151-156. Coturnix: Chapel Hill.
German Cancer Research Center. 2015. A cray-active solution for cancer research. http://medicalxpress.com/news/2015-11-cray-active-solution-cancer.html
Heimer K. 2010. Invasion of self-cloning crayfish alarms Madagascar. Deutsche Presse-Agentur wire story.
Horton J. 2013. Scots wildlife at risk from alien crayfish breeds. The Scotsman. 21 April 2013.
Linzmaier S. 2016. Vom Aquarium in den See. Verbundjournal 106: 14-15.
Löwe K. 2010. Gefahr aus dem Aquarium. Mitteldeutsche Zeitung (Central German Newspaper) news story. 13 October 2010.
Pennisi E. 2015. Crayfish create a new species of female ‘superclones’. Science News ScienceShots. http://dx.doi.org/10.1126/science.aad1673
Privenau K. 2010. Marmorkrebs bringt Pest. Mitteldeutsche Zeitung (Central German Newspaper) news story. 12 October 2010.
Robbins M. 2009. Owning clones. Tropical Fish Hobbyist 57(7): 72-74.
Swedish Agency for Marine and Water Management. 2012. Discovery of marbled crayfish creates concern.
Swedish Agency for Marine and Water Management. 2013. First analysis of marbled crayfish completed.
Missouri has added Marmorkrebs to its prohibited species list, effective 1 March 2011. Read more here. Tennessee designated Marmorkrebs as “Class V wildlife,” meaning they can only be kept by zoos, effective October 2015. Read more here and here.
Link to us
Banners for use in your own website. Windows users, right click and select “Save as.”
This work by Zen Faulkes is licensed under a Creative Commons Attribution-Noncommercial 3.0 United States License.
This site maintained by Zen Faulkes. Last updated 14 February 2017.