Pacifastacus leniusculus

D. and I were walking Omo and let him take a bath in the Gersprenz.
It is a quiet place, a bit hidden, with a beaver built dam 25m away. All three went into the water and when I reached the other side I noticed crayfish near my bare feet. I called D, but when she arrived the crayfish was hiding in the muddy water. When I felt something at my foot I decided to go back.

After a while we saw two crayfish at our side of the rivulet. We were quite excited, never had seen crayfish in their element. We wanted to keep it secret.
At home we discovered that this signal crayfish is a big problem in Europe. It replaces the original crayfish we have here, through the crayfish plague mostly. A few years ago a small lake had to be filled up in order to prevent the signal crayfish to get to the next lake, with Europe's biggest population of noble crayfish, otherwise one signal crayfish would have killed that whole population.
The best way to beat them is to eat them.