http://www.tfhmagazine.com/details/articles/aquarium-science-husbandry-of-the-nautilus-aspects-of-its-biology-behavior-and-care.html
They have a pretty long lifespan for a Cephalopod.
There are a couple of "deep sea" fish that can be maintained in aquaria. Seen some like
Gephyroberyx japonicus, Chaunax spp., Lophiodes spp., Physiculus japonicus, Careproctus rostrinus, several Helicolenus spp. and more in Japanese public aquariums.
Nothing as outlandish looking as viper/dragon fishes unfortunately.