Caridina sp. "Bumblebee" - There are a few color varieties of these guys, only the common form is pictured here. The red form is the "crystal red shrimp" and there's a black form too. These are the most seneitive shrimp to ammonia and the hardest to keep. You don't need an ammonia test kit if you have these guys, if your ammonia goes above absolute zero you have a tank of pink dead shrimp.