Signal Crayfish

We can no longer feast upon the sweet meats of our polite and timid little native northern white-clawed crayfish, for they are now protected. Fat, garish, destructive, obviously American, our rivers are overrun with the signal crayfish, identifiable by its plum-coloured body, blue under-claw (hence its name) and large size. How have we let this happen? During the 1970s, in an attempt to expand crayfish production into a commercial industry, the signal was introduced, favoured for its plumpness and fast growth. It arrived with a virus that our own crayfish were not equipped to repel. Either dying of this plague (which the invaders are immune to) or being left homeless and hungry, our native crayfish, with heads bowed, would shuffle off. Today they have few places left beyond the claws of their adversaries. As a result they are now protected. Meanwhile, the signal marches on, undermining the riverbanks with its burrowing and guzzling everything in its path.