Nautilus aren't really all that difficult, so long as you follow the rules. They've been kept in aquariums since the 1970s I think, originally at the Noumea Aquarium in New Caledonia (which also pioneered the breeding of them). I'll check the details when I get home from work.
OK I've checked out my Nautilus book. The Noumea Aquarium obtained its first live Nautilus in 1958 (although at that time the facility was a private institution and not open to the public) and they've been keeping them ever since then. In 1960 they had 40 Nautilus in their tanks at one time! There had only been one Nautilus kept in captivity prior to Noumea's 1958 one, and that was at the aquarium in Sydney, where it survived for just a week. The first Nautilus to reach North America alive was one captured in Fiji in 1975 by Nautilus researcher Peter Douglas Ward and taken back home with him where it took up residence at the Steinhart Aquarium in San Francisco. In 1976 a dozen specimens from Fiji were put on display at Hawaii's Waikiki Aquarium where they soon started laying eggs, all of which proved infertile as had previous eggs laid at the Noumea Aquarium. It wasn't until 1985 that the first young were hatched in captivity - at the Waikiki Aquarium - after it was discovered that although adult Nautilus survive just fine at constant temperatures (so long as they are cool temperatures) they cannot be bred successfully unless they are given the daily temperature fluctutations that they experience in nature during their vertical migrations to the surface each night to feed.
