NI firm working to tackle signal crayfish threat

[niall_b73 41]

A Donaghadee based company is working to help eradicate the threat caused to native fish by the American signal crayfish.

 

i just seen this page on the news, hopefully it will end the threat from them pesky critters.

 

click on the link below to read the full story:

 

http://www.bbc.co.uk/news/uk-northern-ireland-12562038

 

thankfully they never made it to ireland

 

niall_b73

Edited February 24, 2011 by niall_b73

[CarraghsGem 92]

we've crayfish in our stream, how do i tell the difference between the native white claw and the american invader?

Edited February 24, 2011 by CarraghsGem

[niall_b73 41]

not sure of the proper termonoligy but i always took them to be grey.

manys a day i put in down at the river when i was young trying to catch them without gettin a pinch from them.

 

below is an extract about our native species:

 

For over 20 years we have been studying our largest freshwater crustacean, the white-clawed crayfish, starting with the distribution and habitat preferences of this small freshwater lobster. We then moved on to look at its growth and reproduction in the wild and captivity, its potential for aquaculture, and its value as a bioindicator. Recent collaboration with the University of Poitiers has identified factors leading to the progressive rarity of this crayfish in its natural habitat. In Ireland it is fairly widespread in lakes and rivers, tolerating a slight lowering of water quality, but in France, for other reasons, it is only found in the most pristine streams.

 

Also under question is its presumed native status. The white-clawed crayfish is the only species in Atlantic and southern Europe, from Ireland to Spain to Italy. But how did it get here? Could it be a 'Lusitanian' species, found in Ireland and in Northern Spain like a sizeable number of terrestrial plants and animals such as the arbutus tree and the Kerry spotted slug? A natural colonist from Britain, or an introduction? Genetic studies in Dublin and Poitiers indicate that Irish crayfish are very homogeneous; their closest affinities are with western France, suggesting a relatively recent origin from there.

 

So perhaps our species may have come in with mediaeval immigrants, possibly the aristocratic Cistercians, in the relatively short period before their Irish religious foundations came under the rule of abbots from Britain. Other biogeographic problems of Irish species are accessible to this mixture of history, ecology and genetics. When centuries old museum specimens are included, we have a powerful tool for looking at patterns of distribution, genetic drift and adaptation in native and introduced animals.

 

 

neway... how is the leg

 

niall_b73

[CarraghsGem 92]

sore!

 

im gonna have to catch 1 and see what species is there, theres loads of them anyway

[niall_b73 41]

we've crayfish in our stream, how do i tell the difference between the native white claw and the american invader?

 

wiki

our crayfish

http://en.wikipedia.org/wiki/White-clawed_crayfish

 

the intruder

http://en.wikipedia.org/wiki/Signal_crayfish

 

niall_b73

[CarraghsGem 92]

we've crayfish in our stream, how do i tell the difference between the native white claw and the american invader?

 

wiki

our crayfish

http://en.wikipedia....clawed_crayfish

 

the intruder

http://en.wikipedia....Signal_crayfish

 

niall_b73

 

both look the same to me but going by the size difference i think ive got the white clawed crayfish in our stream

[ratattack 111]

American signals have red on the underside of their pincers