Marmorkrebs

Marmorkrebs
Adult Marmorkrebs
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Crustacea
Class:	Malacostraca
Order:	Decapoda
Family:	Cambaridae
Genus:	Procambarus
Species:	P. fallax
Subspecies:	P. f. f. virginalis

Marmorkrebs, or marbled crayfish, are parthenogenetic crayfish that were discovered in the pet trade in Germany in the 1990s.^[1] Marmorkrebs are closely related to the "slough crayfish", Procambarus fallax.^[2] Procambarus fallax is widely distributed across Florida,^[3] but there are no known natural populations of Marmorkrebs. Information provided by one of the original pet traders as to where they got Marmorkrebs was deemed "totally confusing and unreliable".^[4]

Model organism

Marmorkrebs are the only known decapod crustaceans to reproduce by parthenogenesis.^[1] All individuals are female, and the offspring are genetically identical to the parent.^[5] Because Marmorkrebs are genetically identical, easy to care for,^[6] and reproduce at high rates, they are a potential model organism, particularly for studying development.^[7] A major drawback, however, is the long generation time (several months) compared to other research organisms.^[8]

Invasive species

Marmorkrebs have caused concern as a potential invasive species^[1] because only a single individual is needed to establish a new population, and they can reproduce at high rates. They have since been introduced into natural ecosystems on three continents. They have been found in the wild in Germany,^[4][9][10] Italy,^[11] The Netherlands,^[12] Madagascar,^[13] and Japan,^[14] probably through release or escape from aquaria.

Although most reports of Marmorkrebs in the wild in Europe have consisted of only single individuals,^[9] an established population has now been documented in Germany,^[10] with reports of a second population in another German locale.^[15]

The Madagascar population is growing rapidly,^[13] causing concern among local authorities.^[16]

Although there are no confirmed cases of Marmorkrebs being found in the wild in North America, they are widely distributed among hobbyists in the North American pet trade.^[17] Due to concerns about the possible damage caused by the introduction of Marmorkrebs, Missouri added them to its prohibited species list.^[18]

References

1. ^ ^{a b c} Gerhard Scholtz, Anke Braband, Laura Tolley, André Reimann, Beate Mittmann, Chris Lukhaup, Frank Steuerwald & Günter Vogt (2003). "Parthenogenesis in an outsider crayfish". Nature 421 (6925): 806. doi:10.1038/421806a. PMID 12594502. 
2. ^ Peer Martin, Nate Dorn, Tadashi Kawai, C. van der Heiden & Gerhard Scholtz (2010). "The enigmatic Marmorkrebs (marbled crayfish) is the parthenogenetic form of Procambarus fallax (Hagen, 1870)". Contributions to Zoology 79 (3): 107–118. http://dpc.uba.uva.nl/ctz/vol79/nr03/art03. 
3. ^ Horton H. Hobbs, Jr. (1942). "The crayfishes of Florida". University of Florida Publication: Biological Series 3 (2): 1–179. 
4. ^ ^{a b} Günter Vogt, Laura Tolley & Gerhard Scholtz (2004). "Life stages and reproductive components of the Marmorkrebs (marbled crayfish), the first parthenogenetic decapod crustacean". Journal of Morphology 261 (3): 286–311. doi:10.1002/jmor.10250. 
5. ^ Peer Martin, Klaus Kohlmann & Gerhard Scholtz (2007). "The parthenogenetic Marmorkrebs (marbled crayfish) produces genetically uniform offspring". Naturwissenschaften 94 (10): 843–846. doi:10.1007/s00114-007-0260-0. PMID 17541537. 
6. ^ Stephanie A. Jimenez & Zen Faulkes (2010). "Establishment and care of a laboratory colony of parthenogenetic marbled crayfish, Marmorkrebs". Invertebrate Rearing 1 (1): 10–18. http://inverts.info/content/establishment-and-care-laboratory-colony-parthenogenetic-marbled-crayfish-marmorkrebs. 
7. ^ Frederike Alwes & Gerhard Scholtz (2006). "Stages and other aspects of the embryology of the parthenogenetic Marmorkrebs (Decapoda, Reptantia, Astacida)". Development Genes and Evolution 216 (4): 169–184. doi:10.1007/s00427-005-0041-8. 
8. ^ Günter Vogt (2010). "Suitability of the clonal marbled crayfish for biogerontological research: A review and perspective, with remarks on some further crustaceans". Biogerontology 11 (6): 643–669. doi:10.1007/s10522-010-9291-6. PMID 20582627. 
9. ^ ^{a b} Peer Martin, Hong Shen, Gert Füllner & Gerhard Scholtz (2010). "The first record of the parthenogenetic Marmorkrebs (Decapoda, Astacida, Cambaridae) in the wild in Saxony (Germany) raises the question of its actual threat to European freshwater ecosystems". Aquatic Invasions 5 (4): 397–403. doi:10.3391/ai.2010.5.4.09. 
10. ^ ^{a b} Christoph Chucholl & Michael Pfeiffer (2010). "First evidence for an established Marmorkrebs (Decapoda, Astacida, Cambaridae) population in Southwestern Germany, in syntopic occurrence with Orconectes limosus (Rafinesque, 1817)". Aquatic Invasions 5 (4): 405–412. doi:10.3391/ai.2010.5.4.10. 
11. ^ Francesco Nonnis Marzano, Massimiliano Scalici, Stefania Chiesa, Francesca Gherardi, Armando Piccinini & Giancarlo Gibertini (2009). "The first record of the marbled crayfish adds further threats to fresh waters in Italy". Aquatic Invasions 4 (2): 401–404. doi:10.3391/ai.2009.4.2.19. 
12. ^ D. M. Holdich & M. Pöckl (2007). "Invasive crustaceans in European inland waters". In Francesca Gherardi. Biological Invaders in Inland Waters: Profiles, Distribution, and Threats. Dordrecht, the Netherlands: Springer. pp. 29–75. doi:10.1007/978-1-4020-6029-8_2. ISBN 978-1-4020-6029-8. 
13. ^ ^{a b} Julia P. G. Jones, Jeanne R. Rasamy, Andrew Harvey, Alicia Toon, Birgit Oidtmann, Michele H. Randrianarison, Noromalala Raminosoa & Olga R. Ravoahangimalala (2008). "The perfect invader: a parthenogenic crayfish poses a new threat to Madagascar's freshwater biodiversity". Biological Invasions 11 (6): 1475–1482. doi:10.1007/s10530-008-9334-y. 
14. ^ Tadashi Kawai & M. Takahata, ed (2010). The Biology of Freshwater Crayfish. Sapporo: Hokkaido University Press. ISBN 978-4-8329-8194-2. 
15. ^ Kornelia Privenau (12 October 2010). "Marmorkrebs bringt Pest". Mitteldeutsche Zeitung. http://www.mz-web.de/servlet/ContentServer?pagename=ksta/page&atype=ksArtikel&aid=1286541132341&calledPageId=987490165154. 
16. ^ Klaus Heimer (18 August 2010). "Invasion of self-cloning crayfish alarms Madagascar". Deutsche Presse-Agentur wire story. http://www.earthtimes.org/articles/news/339974,alarms-madagascar-feature.html. 
17. ^ Zen Faulkes (2010). "The spread of the parthenogenetic marbled crayfish, Marmorkrebs (Procambarus sp.), in the North American pet trade". Aquatic Invasions 5 (4): 447–450. doi:10.3391/ai.2010.5.4.16. 
18. ^ Anonymous (17 May 2010). "Conservation Action Meeting of the March 2010 Conservation Commission". Missouri Department of Conservation. http://mdc.mo.gov/about-us/get-know-us/organization-structure/conservation-commission/meetings-and-minutes/2010-meeti-1. Retrieved November 28, 2010. 

External links

• Marmorkrebs.org
• MarbledCrayfish.com