Those look a lot like PK shrimp that I am familiar with. Chances are very high they are PK shrimp. It is very doubtful that those pictured and surviving in his winter chilly pond are the more tropical species sold in pet shops. We have to assume they have a gene pool tolerant of northern winters. Remember one has to have correct habitat for them to thrive in a sportfish pond. Correct habitat means - weedy, that provides lots of cover as a refuge from predation by mostly panfish.
