The only freshwater eels that I am familiar with are actually migratory, I forget the proper term but it is the opposite to salmon (androgenous?)where they spawn in fresh then migrate to salt. Our eels spawn in the Sargasso Sea then migrate to the various freshwater sites around the world, where they live out their lifespan, then return to the Sargasso to spawn and die. Right now there is a very serious problem with the world wide eel population crashing, to the point that they are being declared endangered both here and in Europe. If you search on the Fish Ontario website forum there is a lot of info. Short aqnswer-no they cannot reproduce in a pond.