Any self-respecting freshwater aquarist (such as myself) knows of the plecostamus. Also known as the janitor fish, they make for great tank cleaners. But to folks in the Philippines they are a menace.
The pleco was introduced to several river systems in the Philippines with the intent of having them clean up the rivers. The plecos dined on the waste, detritus, and filth. The program worked. But them the plecos, now running out of garbage to eat, began to turn to endemic species to feast upon.
Philippine officials are now scratching their heads and wondering what to do. These fish are nigh on indestructible. They've got armored plating, can eat anything, and have a rabbitesque ability to reproduce. Officials have turned to dredging the river bottoms in an attempt to slow down the advance and spread of the pleco. And local fishermen are of no help, since the pleco, with all of its garbage eating, isn't really edible.
