Five incredible facts about the paper nautilus
1. Not a nautilus The paper nautilus (Argonauta spp.) is actually an octopus.
2. The shell The shell is actually an egg incubator. Females make it themselves by secreting a form of calcium, creating a paper-like shell (hence the name, paper nautilus).
3. Life in the water column Paper nautiluses live in the water column, just like real natilusus do, but unlike other octopuses, that live on the ocean floor.
4. Size disproportion Male paper nautilus are less than 2.5cm long, while females grow to more than 37cm. Females are also 600 times heavier than the males.
5. Losing limbs When the male and female mate, the male leaves behind an arm!