brewcm, that pic you posted is definitely a mysis shrimp. They are great to have in your tank.
did you know hat they only carry one baby at a time? It is born a tiny little shrimp. Makes you wonder where they all came from knowing that, right? The point is that a wrasse or mandarin can eat them faster than they can reproduce in most tanks even though they tend to be nocturnal and retiring to caves and holes.