Hobbiests generally use the term "pods" to describe the very small crustaceans in our tanks that are named with the pod ending.....copepods, amphipods, and isopods are generally meant when a hobbiests says "pods". "pods" means "foot" in greek I believe.....copepod translates to oar+foot because they have flat legs for swimming, I believe amphipod means double feet or something....don't get that, but whatever......It's sort of misleading when you have common things like gastropods....belly+foot, and they aren't included....basically hobbiests generally mean the three when "pods" are mentioned. Most are good, a few are bad......just little crustaceans.