crayfish threatens native species
Thursday, February 20, 2003 By Reuters
LONDON — A mysterious self-cloning female crayfish, popular with
German aquarium owners, could pose a threat to native European
species if it were released into the wild, scientists said
The marbled crayfish, called Marmorkrebs, is probably related to a
North American species, although scientists at Humboldt University
in Berlin admit they do not know exactly where it originated.
But they are sure that it can reproduce without mating.
Parthenogenesis, a form of
self-cloning, is found in creatures such as snails and water fleas
but is unusual in crayfish.
The Marmorkrebs' ability to produce 20 or more clones of itself in
six months could create a competitor to crayfish in the wild,
according to Gerhard Scholtz, a
comparative zoologist at the university.
"It might pose a threat to European native crayfish," he
Marmorkrebs, which can be bought for about five euros (US$5) in
Germany, may also be able to transmit a deadly crayfish plague to
other less robust
species, according to Scholtz, who published his findings in the
science journal Nature.
"This crayfish, which is now widespread in Europe's aquaria,
could become a menace to European freshwater ecosystems, as the
release of even one specimen into the wild would be enough to
found a population that might out-compete native crayfish,"
he said in the report.