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And there is more bad news: "Marbled crayfish act as carriers of the crayfish plague - a fungal infection to which our native crayfish species is highly susceptible," said Dr Birgit Oidtmann, crayfish plague specialist at Cefas. "This same disease was brought into the UK by signal crayfish from North America, with serious impacts on native populations."

1. signal crayfish - определения в Интернете на английском:
The signal crayfish, Pacifastacus leniusculus, is an American crayfish indigenous to the western US. Due to the crayfish plague that ravaged European crayfish stocks and has almost exterminated the noble crayfish Astacus astacus, Swedish biologists searched for a crayfish that could replace the native European crayfish. They found the signal crayfish and started to introduce it into Swedish rivers and lakes. ...
en.wikipedia.org/wiki/Signal_crayfish

2. http://www.google.com.ua/search?hl=ru&q=+%22Pacifastacus+leniusculus%22&btnG=%D0%9F%D0%BE%D0%B8%D1%81%D0%BA&meta=lr%3Dlang_ru

Сигнальный рак