pearmonger's Identifications

This is a Signal Crayfish, we found it at Bolton Abbey. It is an invasive species doing great damage to native populations. I think it’s an offence to release a non native species, so once you catch one you have a dilemma. Do you kill it? I don’t like killing things that I’m not going to eat. One wouldn’t make much of a meal but I know people who do the native wildlife great service by trapping and cooking them.