Voracious mutant female crayfish clone themselves, taking over world

They eat everything, spread out of control - and don't need no males.
They eat everything, spread out of control - and don't need no males. Photo credit: Darrick Vanderwier / YouTube

An all-new species of mutant crayfish has done away with males - and is poised to take over the sea.

The female species is known as marmorkrebs or marbled crayfish. It began when an individual evolved the ability to clone themselves, laying genetically identical all-female eggs.

It first became popular among German petshops and aquarium hobbyists in the 1990s, because of its ability to produce hundreds of eggs at a time, without male partners.

But the marmorkrebs escaped into the wild, where they began to multiply out of control. They have now spread across Europe and Africa, cloning in huge numbers and taking over ecosystems.

"They eat anything - rotten leaves, snails or fish broods, small fish, small insects," German molecular geneticist Dr Frank Lyko told Science Magazine.

"This crayfish is a serious pest," adds evolutionary biologist Dr Gerhard Scholtz.

The crayfish has been banned by the European Union, as well as the US states of Missouri and Tennessee.

But while population numbers have exploded, it's not clear if this will lead to the marmokrebs' long-term rule.

Its cloning ability allows it to reproduce quickly, however its genetic similarity means the species is more vulnerable to pathogens and changing environmental conditions.

"Maybe they just survive for 100,000 years," Dr Lyko told the New York Times.

"That would be a long time for me personally, but in evolution, it would just be a blip on the radar."