skitter- they cant reproduce. historicly problems involved with introducing a non-natice species into a new inviroment is that there are no preditors to eat them, which allows them to reproduce, which in turn boosts the #'s and the native species get pushed out- Didnt you see the movie Gremlins??
My point is that if they cant reproduce, they will live their lifespan and die.
Im all for these little fish- they are farm raised, unlike eels which are stripped from ponds, rivers, and estuaries up and down our coasts.