I'm not in a position to comment on the quality of US vs Thai bred stock, but must confess that I am surprised that importing them is even a viable business model as they are so easy to breed. Shrimp are stressed by being moved just like fish, but they are a lot more sensitive than fish. I may have lost more than normal because being shipped for a number of hours no doubt does more harm than a short drive from the LFS - but my LFS did not have what I wanted. Typically the shrimps will be born about 28 days after you notice the female is berried. 4-6 months later the shrimplets will be mature and the cycle repeats. Timing is not precise - everything happens quicker in warmer water where they are more active and grow / breed / die quicker. They are fine and will breed in a fairly wide temperature range.