They are just as sensitive, but remember we are talking about sensitivity to changes without acclimation, particularly from one tank's water to another tank's water. Once established in a system, they tend to be very hardy. It's just that you can't take one out of one tank, and plop it into another (or you can't have huge sudden swings in parameters on your tanks).

That said, there is definitely a lower threshold of salinity for them. I don't know what that is, specifically, but 1.019 is getting to be awfully low of a SG (i.e.,"specific gravity") in my opinion, hence my earlier comments. But the other thing to take into consideration is that if they are being moved into a tank with 1.025 (where most reefs tend to be kept at), that's a difference of 0.006 and that's huge. Therefore it is imperative in such a transition to acclimate as slow as possible. I almost wonder if it would be better to adjust the tank they're in, at 0.001 per day, until the tank is at 1.025, before even moving them into another tank with 1.025. Even a 1.025 to 1.025 transition should have a drip acclimation (in my opinion), for shrimp.

Hope this helps clarify things.

that totaly helps thanks