Hate to point this out, but that's just not true. The species that become invasive are the ones that find good habitat, abundant food sources (with limited competition), and limited or nonexistent predation. They also need to be resiliant to local fish diseases and have their spawning requirements met. I'm going to go out on a limb and estimate that 90% of the species available in the trade have, at one point or another, been released into Florida's natural waterways. A few dozen species have become established; most didn't make it. Exotics that become invasive are hardy generalists, those species that aren't picky about food/water chemistry/breeding/etc. Unfortunately, those are often the species kept by beginners, who are the aquarists most likely to dump their charges in the canal when they tire of them. As for this "pleco ban," I doubt it will ever happen. The pet industry makes big piles of money from loricariids, and will lobby heavily to prevent a ban if and when one seems imminent. Also, fisheries biologists here in Florida, where 2-foot plecos are now common in most river and canal systems, don't seem too concerned about ecological damage from these species. I would think a state ban would have preceded a federal one, if there were much concern. However, a state ban in California wouldn't surprise me.
