Monday, August 23, 2010

Scary crayfish threatens Madagascar

Listen to the frightening description of a new alien species invading Madagascar, and you'll picture something like this (right).
"...voracious self-cloning crayfish, which are gobbling their way through rice paddies and threatening endemic crayfish species."

But what is it really? Just a small "freshwater lobster" (left) that has existed peacably in the Southeastern US until it was apparently accidentally transplanted into Madagascar as a lost or abandoned pet.

That's the dilemma of invasive species--plunking something down in new place can transform it into something harmful. Listen to news reports from Madagascar on this beastie:

Local daily Midi Madagasikara quoted a farmer from a small village on the outskirts of Antananarivo as saying his catch of tilapia had fallen by about 75 per cent since the crayfish appeared.

The crayfish "will eat any plant matter, including rice. In fact, they'll eat any biological matter," the biologists warned.

They also reproduce at an explosive rate, producing up to 400 eggs in 40 days during the warm rainy season.

In 2003, German scientists proved that the marmorkrebs could clone itself. Although the crayfish also reproduced sexually, females were able to lay eggs which hatched without being fertilized.

Known as parthenogenisis, this type of unisex reproduction is effectively a form of natural cloning.

Bad juju. And I grew up thinking crayfish were nothing more than cute and yummy. Maybe a good market will help keep them under control?


jonathan said...

can these not be eaten , if they breed so fast as you say a good market

TruthAdmin said...

Yes, they can. In the Southern Part of the United States they are considered a delicacy. Here's a link

PS: I enjoy your blog.