Australians seem to be especially blessed. Argoanuts are open-ocean cephalopods and we really don't know much about them. They are hard to find, so far they seem to be unpredictable in occurance and to my knowledge no one has kept one alive in an aquarium for more than two weeks. In addition to small crustaceans, they injest some types of prey that most other cephalopods wouldn't consume such as salps and jellyfish. They are very interesting cephalopods from both an aestetic and a biological point of view.
Argonauts are one of the most sexually dimorphic cephalopods.
The females are considerably larger than the males. Females are thought to live longer and reproduce many times while the tiny males are thought to only reproduce once and have much shorter life spans. During mating, one of the male's arms breaks off inside the mantle of the female. So both size and life span are radically different between the sexes. Hundereds of years ago early scientists thought the broken off male reproductive arm was a seperate parasitic creature and they named it a Hectocotylus.