The American crayfish (Orconectus limosus)

Yesterday (Sunday the 26th of July 2009) on television news there was an item about the American crayfish. She marches up in the Netherlands and Belgium alarmingly fast and spreads about all over the the freshwater. Of course one should be prone to cheer the expansion of the domestic fauna with a crayfish, although these beasts are omnivorous and eat really all that comes into their claws. The attempts to destroy the animal proved to be in vain up until now. On the contrary, the animal already was introduced in Germany in 1890 and has got about in great parts of northern and eastern Europe and not so Long ago it has made successfully the crossing from Europe to the United Kingdom. Also in the south of Europe until Serbia the beasts occur. If the pestcontroll has to be successful than really every crayfish has to be caught and slaughtered. ( Eat them is an option because , although the animals measure not more much more than ca 8 inches, the taste is excellent. To extirpate them seems to be an hopeless task
Slowly but surely they begin to become a real plague. The animals eat really all the waterplants out of the water in which they live. With that the water is robbed of its suppliers of oxygen and looses the natural self-regulating power.
Besides all plant life they manage (more clever tan one would expect) to seize and to demolish all animal life like amphibians and fishes. Nothing stays spared. In this Way at last they are responsible for a tremendous deterioration of de fresh waters of the low lands at the sea and I think Germany will not escape it
Of course they have some enemies; The most important ones are they themselves. Just after the ecdysis many a crayfish is cracked and savored by its congeners. Also big ales and perches don't scorn a little crayfish. And after all herons and cormorants are diligent fishers of crayfish.
Considering the above it would be very undeserved to accuse athe Dutch aquaritsts of this aggravating forgery of the fauna , but in my opinion they are not totally not to be blamed .Every one who has occupied himself with this armored knights knows what a clever escapists the concerning animals are
Who needs more information I refer to the concerning pages at my site : http://www.fishnphoto.nl/plts/ 19crust1/19.htm en and 20,21 en 22 (use de "wisvis" under de text)
Also in "'Het Aquarium" has been paid attention to a number of these knights