I'm 110% sure. I've had this tank for 3 years with nothing new introduced other than fish, eels, and these 2 lobsters. I know what all my little copepods and amphipods look like as I have a really good colony thriving in it and see them a lot. These guys don't look anything like shrimp or the shrimp-like amphipods I always have in there. They literally look like tiny clear lobsters, same body structure just no frontal claws. I have never seen anything like them prior to this week, and they were all congregating in the burrow guarded by both parent lobsters.