How Are Male and Female Blanket Octopuses Different?

Male and female blanket octopuses display extreme sexual dimorphism when it comes to size and weight. The female of the species is about a hundred times larger than the male, as well as being tens of thousands of times heavier. Male blanket octopuses are usually just under an inch (2.4 cm) long and weigh less than a tenth of an ounce (0.25 grams). In stark contrast, females are typically about 6.6 feet (2 m) long and weigh about 8 pounds (3 kg).

Blanket octopuses are able to reproduce when the male secretes sperm into a pouch on one of its specialized arms. It then detaches this arm, known as a hectocotylus, and presents it to the female for fertilization. The male dies soon after, thus completing its role in the reproductive cycle of one of the ocean's most bizarre creatures.

More about blanket octopuses:

• Since blanket octopuses are immune to the stings of Portuguese man o' wars, which are similar to jellyfish, they can wield those poisonous stingers as weapons to defend themselves against other predators.
• The first live male blanket octopus was not discovered until 2003, when it was spotted off the coast of northern Australia in the Great Barrier Reef.
• Blanket octopuses get their name from the appearance of the female, which resembles a long and flowing blanket due to the fleshy webs between its arms.