I am a teacher with a 180 L aquarium in the classroom. At the end of the '05 school year, I sold all the fish back to the pet store, not including my beloved tire track eel that mysteriously disappeared about a month earlier.
Flash forward to September '06 and school has started again. The aquarium has been drained of water, there has been no light, heating, or filtration for TWO MONTHS.
When I refilled the aquarium and plugged in all the accessories that make life possible, the filter gurgled into action and spat out a slightly emaciated, but very alive eel - the creature that I thought had jumped out of the aquarium about three months ago. For at least TWO MONTHS without food, he lived in the dark, still, oxygen poor waters in the interior of my Fluval 304 filter.
I put him in my 40 L feeder tank for a few days of open buffet. He looks like he's coming along well, if not a little dazed.