I do believe they are easy to spread, I have no doubt that releasing them into waters anywhere is a bad idea. I see no reason i cannot think about them or contemplate how they might live in an aquarium. I do not support keeping them in any way. I do doubt very seriously they could cause a problem in small aquarium long term. when first set up an aquarium can support mussels and clams but as the aquarium ages food sources become few and far between and the population of filter feeders become severely limited. I've seen it in salt water with sponges, clams, oysters and various tube worms covering everything at first but over the long term the populations die back to very limited numbers. I do not see how the open environment of pipes being furnished with fresh new water consistently can compare with a closed system. Be that as it may I do not suggest anyone keep zebra mussels, i however do not think they will grow on my carpet, take over my bed room and impregnate my dog. Living in a closed septic tank would be a neat trick, no oxygen would limit even zebra mussels. considering complex life forms, even those much tougher than zebra mussels, do not generally live in septic tanks but again as I said I see no reason to test out that theory. But I again to ask how would keeping them in an area where they are already occupying every possible habitat harm anything? Assuming you don't flush them into open sewers or dump them at all much less anywhere they are already not endemic? I've was offered rocks covered with zebra mussels many times when I was trading fishes and I turned them down due to the possibility they might escape accidentally but it does not keep me from thinking about such animals in an aquarium. Where i live i often find small mussels attached to plants and wood, I've thought of trying to keep them to see how they do in an aquarium but they seem to be food for most fishes I keep.
