Oceans are home to some of the most fascinating and mysterious creatures that have survived on our planet for millions of years. One of them is the eight-limbed, soft-bodied mollusk, octopus.

Blanket octopus pairs are some of the undersea world’s oddest couples. What’s so startling is the size difference: Males are about the size of a walnut—less than an inch long—but some ...

This story ran in the April 2016 issue of National Geographic magazine. In most octopus species it’s customary after sex for the female to make a meal—of her partner. To avoid being eaten ...