I don't cut their head, I just take one and flatten their spike on the kitchen table one at a time, if the shrimp is bigger than 1.5", else they get the shrimp as is. Just afraid of the sharp spike.
I receive live ghost shrimp, which I then freeze and make it a point to clear out the stock in less than three weeks, as after three weeks even in zero temp they lose their nutritional value. So their gastrointestinal organs shouldn't be toxic in such a short period of time.
Dang I didn't know they would lose their nutritional value so quickly -- I only have easy access to already frozen ghost shrimp and I'm sure it's mostly older than 3 weeks by the time I get it
