Planted Tank Enthusiast
Join Date: Sep 2009
Location: Seattle, Washington
Shrimps actually tend to weather shipping better if they're juveniles. Shipping cherry shrimp at 1/4 inch is rather common. But if they are 'assorted' shrimp and they are too young to identify, it is kind of silly. I've found that the LFS near me tends to be sloppy with their shrimp, and tends to have a hybrid mess because they just throw them all in one tank.
A styrofoam-lined box and a 48 or 72 hour heat pack can get your shrimps to you in good condition if you pay for fast shipping. As long as the mail is not stopped because of weather they should be okay. (I wouldn't buy any really expensive or delicate ones that way; tiger shrimps should be okay.)