Marmorkrebs or marbled crayfish are parthenogenetic crayfish that were discovered in the pet trade in Germany in the 1990s (Scholtz et al. 2003). The location of natural populations (if any) of this species is unknown. Information provided by one of the original pet traders as to where they were obtained was deemed "totally confusing and unreliable" (Vogt et al. 2004). Nevertheless, Marmorkrebs appear to be closely related to North American crayfish in the genus Procambarus that are sold as pets rather than European crayfish (Scholtz et al. 2003), suggesting that they are not native to Europe. This species currently has no formal scientific name. Marmorkrebs are the only known decapod crustaceans to reproduce by parthenogenesis. All individuals are female. Offspring are genetically identical to the parent, indicating they reproduce by apomixis (Martin et al. 2007). Because Marmorkrebs are genetically identical, easy to care for, and reproduce at high rates, they are a potential model organism, particularly for studying development (Alwes & Scholz 2006). Marmorkrebs have been found in the wild in Germany (Vogt et al. 2004) and Madagascar (Jones et al. 2008), probably through release or escape from aquaria. Because Marmorkrebs reproduce at high rates, and given the history of invasive species that were introduced through the pet trade, there has been substantial concern that Marmorkrebs are a potential pest species. Marmorkrebs can survive fairly low temperatures, which would allow them to overwinter in Europe (Seitz et al. 2005). ReferencesAlwes F & Scholtz G. 2006. Stages and other aspects of the embryology of the parthenogenetic Marmorkrebs (Decapoda, Reptantia, Astacida). Development Genes and Evolution 216(4): 169-184. http://dx.doi.org/10.1007/s00427-005-0041-8 Jones JPG, Rasamy JR, Harvey A, Toon A, Oidtmann B, Randrianarison MH, Raminosoa N & Ravoahangimalala OR. 2008. The perfect invader: a parthenogenic crayfish poses a new threat to Madagascar’s freshwater biodiversity. Biological Invasions: in press. http://dx.doi.org/10.1007/s10530-008-9334-y Martin P, Kohlmann K & Scholtz G. 2007. The parthenogenetic Marmorkrebs (marbled crayfish) produces genetically uniform offspring. Naturwissenschaften 94(10): 843-846. http://dx.doi.org/10.1007/s00114-007-0260-0 Scholtz G, Braband A, Tolley L, Reimann A, Mittmann B, Lukhaup C, Steuerwald F & Vogt G. 2003. Parthenogenesis in an outsider crayfish. Nature 421(6925): 806-806. http://dx.doi.org/10.1038/421806a Seitz R, Vilpoux K, Hopp U, Harzsch S & Maier G. 2005. Ontogeny of the Marmorkrebs (marbled crayfish): a parthenogenetic crayfish with unknown origin and phylogenetic position. Journal of Experimental Zoology A 303(5): 393-405. http://dx.doi.org/10.1002/jez.a.143 Vogt G, Tolley L & Scholtz G. 2004. Life stages and reproductive components of the Marmorkrebs (marbled crayfish), the first parthenogenetic decapod crustacean. Journal of Morphology 261(3): 286-311. http://dx.doi.org/10.1002/jmor.10250 External links
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