Published online 20 February 2003 | Nature | doi:10.1038/news030217-9


First self-cloning crayfish found

Mystery crustacean could pose risk to European cousins.

Marmokrebs could be good for lab studies.Marmokrebs could be good for lab studies.Source: Nature

A mysterious species of crayfish discovered in German aquaria can reproduce without mating1. It could pose a serious threat to their European freshwater cousins, new research shows.

It's too late to ban the creatures, experts think. But efforts should be made to prevent their accidental release. "The public should be alerted," urges crayfish researcher Gerhard Scholtz of the Humboldt University of Berlin.

Scores of the 8-centimetre-long female crayfish, distinguished by their marble-patterned shells, appeared in the German aquarium trade in the 1990s. Rumours of virgin births soon began to circulate among amateur aquarists.

Scholtz and his colleagues now confirm that the creature, informally named Marmorkrebs, can indeed clone itself without recourse to male fertilization. This remarkable talent, called parthenogenesis, is known in some higher crustaceans, but has never been seen before in crayfish or their crab and lobster cousins.

More worryingly, Marmorkrebs seems to be closely related to the North American crayfish Procambarus fallax, and may therefore carry a highly infectious fungus that the American strain is known to harbour. When P. fallax was released into European waters in the nineteenth century, the fungus decimated native crayfish. "Most European crayfish are now endangered," says Scholtz.

This suggests that the release of just one Marmorkrebs into a European ecosystem could put natives at risk.

The arrival of Marmorkrebs isn't all bad news. Its large eggs and ability to self-clone could make it a useful organism for laboratory studies of evolution and embryonic development, suggests Scholtz. And it apparently tastes good, too. 

  • References

    1. Scholtz, G. et al. Parthenogenesis in an outsider crayfish. Nature, 421, 806, (2003).  | Article | ISI | ChemPort |