I noticed some movement in the shallow water of some of the drainage ditches. They were literally full of crayfish, some were dead and others were not that lively, a few were still ready for a fight. I think the water levels were down and there was a lack of oxygen so they were suffering. Surprisingly no predators seemed to be making use of this food source. I considered collecting up a bag full for dinner, but not being sure what might have been sprayed on the fields and if this might also be a reason why they were suffering I decided against it.
This is an introduced species from SE America, (Louisiana), the native species is now quite rare, rather like our own crayfish in the UK.
In Spain crayfish is called cangrejo de río (lit. “river crab”).