My Dats will only eat pre-cooked shrimp. Usually, any shrimp (raw or cooked) which has been subjected to freezing will at least contain NaCl. I cut up the shrimp a day ahead of time and soak it overnight in tap water to diffuse out the salt. Sometimes, I follow this up by using paper towels to get rid of excess water and then soaking the shrimp pieces for a couple of hours in Kent Zoe before feeding. I think it's a good way to augment their diet.