About 25 years ago, a band called King Missile came out with a song called "Detachable Penis," and its weirdness developed a cult following. The song is very creative but seemingly meaningless, unless it's describing octopuses, in which case removing one's genitalia is a common part of a very weird life cycle.
Before we explore these oddities, let's talk about what all octopus species have in common: eight sucker-lined arms with a beaked mouth in the middle, plus lots of intelligence. One thing the world's smartest invertebrates do not have in common is how they make more octopuses. As you'll see, often how these animals reproduce depends on what kind of shelter is available.
From detachable penises, to cannibalism, to beak-to-beak makeout sessions, here are some weird ways these suckers get it on, care for their clutches and ultimately die.
Take my hectocotylus, please!
The blanket octopus spends its time propelling itself just under the surface of the open ocean — a place without much shelter — to hide a clutch of eggs. Females of this species can reach 2 meters. Most of their length consists of drape-like webbing that connects some of their arms together, giving the blanket octopus its name. The males, however, are about 2.5 centimeters long. That's like a 6-foot tall person mating with somebody the size of their thumbnail! This is the largest known sexual dimorphic gap in the animal kingdom (at least outside of microscopic life).
Once these two unlikely mates actually find each other in the vastness of the seas, what happens next is pretty strange, too. The teeny male removes one of his arms, basically a sperm-filled sack called a hectocotylus, and gives it to the female. She tucks the arm away in a hole in her mantle. Once he parts with his hectocotylus, the male will die. He lives a short life which is sacrificed for love.
Whenever the female is ready to reproduce, she'll squirt the collection of sperm packets she's amassed onto her clutch of eggs.
While we're talking about sexual dimorphism and giving away sperm-filled arms in the open ocean, we can't overlook the argonaut octopus. They're also known as the paper nautilus because of that groovy spiral shell which resembles the shell of a fellow cephalopod, the chambered nautilus.
For centuries, humans thought that the argonaut used her elongated arms as sails and her shell as a boat. While she does trap some air in her shell to remain buoyant, it's hardly a ship. The shell is mainly used to house her eggs. Unlike most octopuses, which live on the sea floor and have access to sheltered places like caves or burrows, argos live in the open ocean, like the blanket octopus. This lack of shelter for their clutch of eggs forced them to develop this shell-like substance which provides protection for the female and her offspring.
As if an octopus having a shell wasn't odd enough, the argo courtship is even odder. When a male argo senses a female, his hectocotylus pops off his head and FREELY SWIMS into the female's shell! Also like the blanket octopus, the female will collect the severed arms of males until she’s ready to fertilize her eggs. Read all about argonauts here.
By the way, until this mating act was witnessed, people used to think the hectocotylus lodged in argo shells was actually a parasitic worm!
There's always an exception
Octopuses are usually solitary, antisocial and hungry. So for males — especially the little ones — mating is the ultimate risk. Basically they either get eaten or simply die after they pass on their genes.
Recently, scientists in California found a rare species of octopus that's different from the norm, the clumsily named Larger Pacific Striped Octopus (LPSO). Not only do the males live after they copulate, the female doesn't usually put her mate at risk.
Exception part 2
Incredibly, these octopuses are tolerant of each other's presence. As a bonus, they've been observed sharing food and living together, too. There's so much love between the LPSOs that they even mate beak to beak. It almost looks like they're kissing.
Parents with senescent moments
Whether living together like the LPSOs or being a cannibal, most cephalopods live one to two years. Their life consists of a lot of very fast growing, eating, mating and death. Well, more like a prolonged death. Once the females eggs are fertilized, they stop eating and do nothing but watch over the clutch, ventilating them with their siphons. This is a state called senescence. The longest known "watchful mom" stage comes from a purple deep sea octopus that hung around her babies for 53 months.
For such brainy creatures, it seems odd that cephalopods live such short lives. I can't help but wonder what they'd be capable of if they didn’t die so quickly.