Marmorkrebs: Natural crayfish clone as emerging model for various biological disciplines

Abstract

In the last decade, the Marmorkrebs or marbled crayfish (figure 1A) has become very popular among hobby aquarists and researchers (Vogt 2008a, 2010; Faulkes 2010). The name comes from its typical coloration that resembles marble. The marbled crayfish belongs to the decapod crustaceans, which include the commercially valuable shrimps, lobsters, crayfish and crabs. It was discovered in the mid-1990s in the German aquarium trade (Scholtz et al. 2003; Vogt et al. 2004) and has only recently been identified as the parthenogenetic form of the slough crayfish, Procambarus fallax (HAGEN, 1870), which is native to Georgia and Florida, USA (Martin et al. 2010a). Its scientific name is therefore Procambarus fallax (HAGEN, 1870) f. virginalis (Martin et al. 2010a). The marbled crayfish is the only one of more than 10000 decapods that produces high amounts of genetically identical offspring by obligatory parthenogenesis (Martin et al. 2007; Vogt et al. 2008). Mainly because of its clonal nature and easy culture, it was introduced as a laboratory animal around the year 2000. At present, it is used by more than a dozen laboratories in Europe, Japan and the United States as an experimental animal for a variety of research purposes. The marbled crayfish grows step-wise by moulting, passing approximately 25 moulting cycles in its lifetime. Adult marbled crayfish usually have body lengths of 4–8 cm (without chelae) and weights of 1.5–15 g. Very large specimens can reach 12 cm and more than 25 g. In the laboratory, the average lifespan of the adults was 720 days, but the record is 1610 days (Vogt 2010). Marbled crayfish can be kept either individually or communally in simple housing systems. They can tolerate broad ranges of environmental conditions for longer periods of time (Vogt et al. 2004; Jimenez and Faulkes 2010). The embryonic and first juvenile stages can even be raised in micro-plates (Vogt 2007). All life stages can be fed with the same pellet food (for instance, Tetra WaferMix), which is very exceptional in animal culture. Generation time is approximately 6 months.