found this online:
Associated Press, 2008/06/01
In an amazing discovery, Scientist C. Moore has found a species of octopus that lives in freshwater streams of northern Papua-New Guinea.
Once thought to be solely saltwater inhabitants, this dwarf octopus thrives in the narrow streambeds that course throughout the island chain, feeding on small fish and hiding in snail shells.
The locals seem to have known about the animal for quite a while, and Dr. Moore became convinced of its existence after eating an odd plate of escargot while on a train stop in the Philippines. The doctor noticed some sucker marks on a few of the shells, and asked if they were truly fresh snails, when assured they were, he demanded to know the location of where they were purchased.
Not two months later, he had tracked down the snail trail, and found what he was looking for, the elusive Octopus pureninsis, the only freshwater octopus ever recorded in human history.
Captive bred specimens are even now making their way to the west, where they will be further studied by zoologists and aquarium keepers.
B.Lumley, New Guinea