According to a report in the Journal of Experimental Biology (June 2008), nautilus, those ancient ancestors of modern cephalopods, have both long- and short-term memory, despite a lack of brain structures for memory. In an experiment where the shelled creatures were trained to associate the smell of food with a blue light, they extended their tentacles in response to a flash of the light for an hour, then six hours after the training. (For more on body brains, see here.)