We have established that this protocol works for multiple species, including D. pulex, D. pulicaria, D. dentifera, D. magna, D. ambigua, D obtusa, and D. lumholtzi. It should work more broadly.
1. The main objectives are to control temperature (for most species, the problem is the package may get too hot), and oxygen. Oxygen can be depleted by decaying algae, so limit the the quantity of food you add to each tube. Well-fed Daphnia can be shipped without food, but may initially produce male offspring after being received.
2. In the U.S., most overnight shipping goes through the Memphis, TN airport because it is the least likely to experience weather disruptions. However, if you've only got one chance to send the Daphnia, check the weather report for Memphis and make sure it is clear.