Tilapia wre almost certainly aquarium releases and have the potential to inhabit/ invade/dominate the entire non-arctic aquatic domain if you were swayed by Heiko Bleher's lament. They used to die in their thousands every winter in Lake Samsonvale (near m
y home: and no it wasn't me who put them in there) but they are now much more cold-tolerant thank you very much and selection of the fittest is working very well. So this highly adaptable fish can handle all kinds of water quality/pH, salinity, wide range
s of temperature and almost anbything else that is thrown at them. They can breed in small ponds, escape into streams after rains, colonise almost every habitat in that stream and still survive washing down the stream into saline sections and swim up the
next stream along the coast and colonise that one too. What a fish. We need to find a biological control in the form of a "fish AIDS" very soon. Hopefully one that only affects Cichlids.
The other major introduced pest, Gambusia was still being recommended for mosquito control for farm dams until a very few years ago by the DPI. And even now people still refer to them as- "guppies" affectionately. The true Guppy is not in very many stream
s as far as I know and is not nearly as aggressive as the "Big G".
I do like the term"dambusia" - good one Peter.I think the authorities will have missed the boat if they don't design their guidelines soon for the new phenomenon of Artificial Wetlands that are being designed into numerous developments and factories . Th
e piscine inhabitants are often--not even considered important enough to get a responsible opiniom on . So the Botanist/LandscaperEngineer--makes the decision - "We need mosquito control! Use "Mosquito Fish". And there goes anotherchance for the local spe
cies to find a useful role as well as a refuge. And worse, the "dambusias" get a head start, as if they need one.
I agree with you Peter, we have tobe careful about the potential for these forage/wet lands/mosquito uses for our smaller species to be escapees and contaminants of non-natural watersheds. I think our DPI here in Qld has-- some suggestions for farmers etc
but no legislative teeth as yet.
Bruce Hansen ---
Attachment Converted: c:\eudora\attach\RE In defence of the aquarium 2