They do show reflexes and grooming behaviours for injured antennae so there are some basic pain responses. I agree that the difference in suffering between electrocution and freezing is probably marginal at best, whichever way you go. The ice slurry also can crush and suffocate the shrimp if they survive the cold, but mostly it involves thermal shock, due to the quick change in temperature.
They do show reflexes and grooming behaviours for injured antennae so there are some basic pain responses. I agree that the difference in suffering between electrocution and freezing is probably marginal at best, whichever way you go. The ice slurry also can crush and suffocate the shrimp if they survive the cold, but mostly it involves thermal shock, due to the quick change in temperature.