Around the time that they reach adulthood, male and female octopuses all experience the irresistible instinct to mate.
Octopuses have short lifespans of between about six months for small tropical species and five years for the giant Pacific octopus (Enteroctopus dofleini).
However, sadly for them, reproduction is one of the last things they do in their short lives.
The male will die quite quickly after mating, and the female dies shortly after her eggs have safely hatched.
As we try to answer why do octopus die after mating, we will see that while scientists aren’t sure of the reason, it may have something to do with preventing overpopulation while also protecting the young from cannibalism.
We’re going to look at the mechanism by which octopuses enter the last stage of their life called senescence, where they stop eating, and their bodies break down.
It may sound sad that octopuses are semelparous animals (they reproduce and then die).
However, it seems that, particularly in the case of how female octopuses die, this ultimate sacrifice ensures the next generation’s successful birth and life.
What Is Senescence in Octopus?
To understand why do octopus die after mating, we need to learn about octopus senescence.
The dictionary describes senescence as “the condition or process of deterioration with age” and the “loss of a cell’s power of division and growth.”
Essentially, it is when the organism, in this case, the octopus, stops repairing itself, causing it to die slowly.
Senescence is a clearly defined part of the lifecycle of many animals, and in the octopus, it is integrated with the mating process.
The octopus enters senescence when it reaches adulthood and needs to reproduce.
There are four indicators that marine biologists use to assess if senescence has started:
- Loss of appetite and lack of feeding leading to weight loss
- Retraction of the skin around the eye
- Undirected or uncoordinated activity
- White lesions on the skin (no longer camouflaged)
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Octopus senescence is triggered when secretions from the optic gland between the octopus’s eyes induce the ripening of the animal’s reproductive organs to make them ready for mating.
So, without this process of guaranteed eventual death beginning, reproduction cannot take place.
Stopping eating will naturally cause the octopus to eventually starve, making rapidly finding a mate extremely important.
In 1977 scientists studying octopus senescence removed the optic glands from female Caribbean two-spot octopuses (Octopus hummelincki) who were going through senescence while tending to their egg clutches.
When the scientists removed the optic glands, the females stopped looking after the eggs and resumed feeding again.
Senescence was halted for six months afterward until the females succumbed to old age.
By removing the optic gland, the scientists stopped the so-called “self-destruct system” that guarantees the octopus’s death after reproduction.
However, it also caused the thousands of octopus eggs to die without the female tending them.
Why Do Male Octopus Die After Mating?
Do male octopus die when they mate? Yes, and scientists have suggested that causing male post-reproductive death may have evolved to prevent overpopulation in an area.
Alternatively, it may simply be that senescence creates a biological urgency for mating to take place and that once it has, the male octopus’s job is done, and he is no longer needed.
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When they’re near the end of their lives, the male octopus seems to lose control of its body.
The famous nine brains seem to lose their effectiveness, and the animal will lack coordination which often attracts predators.
How Do Males Octopuses Die After Mating?
Once the male has done its part in reproduction, his death will occur, usually in one of four ways:
- Being killed by the female
- Being killed by a predator
- Disease from being unable to heal their skin
- Dying due to starvation
Females can be highly aggressive and frequently kill their partner during reproduction.
Often the female will drag the dead carcass of her partner into her den where she can enjoy a final meal.
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Why Do Female Octopus Eat Their Mate?
Unlike the male, for whom reproduction is his last duty before eventual death, the female must stay alive long enough to tend her eggs until they hatch.
In the case of the great Pacific octopus, this can be for as long as six to seven months.
So, it may be that before senescence ultimately robs the female of the ability to feed, she eats the male to get one final protein-rich meal.
Do Female Octopus Also Die After Mating?
The female octopus’s lifespan is also terminally limited as soon as senescence, driven by secretions from the optic gland, begins.
However, unlike the male, who will die quickly after reproduction has finished, the female needs to live on to tend her eggs until they hatch.
Females constantly watch their eggs and protect them from predators. She also needs to waft fresh water over the eggs with her arms to provide oxygen, keep the eggs clean and remove algae.
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So, the answer to “Do octopus die after giving birth?” is yes. Males die immediately, but females live on until the eggs hatch, when they will then die.
Researchers have noted that females go through four distinct stages of senescence:
- The female is mature, but reproduction hasn’t taken place. The female appears to behave normally and will leave its den to hunt for food.
- Mating has taken place. She has laid her eggs and is tending them. For 3-4 days after mating, while the octopus won’t hunt, she may take an opportunistic passing meal.
- She stops eating entirely and loses energy while continuing to tend her eggs.
- Shortly after eggs have hatched, the female octopus will die. Beforehand, she starts to act as if irritated, and in research aquariums, specimens will slam themselves aggressively against the tank walls. Legs can become tangled, and the octopus is highly ragged.
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As the female octopus looks after her brood, she literally consumes her own body and will lose between 50-71% of her body weight.
After using all her energy from her last meals, including perhaps from eating the male octopus, she will break down her own tissues or even cannibalize her skin or her own arms to stay alive long enough to look at the eggs.
It’s suggested that females lose their ability to feed before giving birth partially due to their cannibalistic tendencies.
If a female was still feeding as usual, she might well eat her eggs or even her own young when they finally hatch.
Once the octopus eggs hatch, the female will quickly die. The hatchlings will drift off into the water column as plankton before eventually dropping back to the sea bed to start their own growth toward maturity and reproduction.
How Long Do Octopus Survive After Mating?
Octopuses have relatively short semelparous lives and die soon after mating.
The difference between the lifespans of males and females is that the female stays alive long enough to look after her eggs until they hatch.
How Long Do Octopuses Live?
Octopuses live between about six months and five years, depending on the species.
These are some examples:
Star-sucker pygmy octopus (Octopus wolfi) 6 months
Common octopus (Octopus vulgaris) 1-2 years
Blue-ringed octopus (genus Hapalochlaena) 2-3 years
Larger Pacific striped octopus (undescribed) 2 years
Giant Pacific octopus (Enteroctopus dofleini) 3-5 years
How Long Does a Male Octopus Live After Mating?
Senescence in male octopuses typically lasts between a week and a few months, depending on the species.
The male must use this time to find a mate and reproduce, which can take some time depending on how many octopus females are around.
Usually, most male octopuses will die shortly after mating – typically within two weeks.
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Aquarium great Pacific octopus males have been seen to live without eating for between 14 to 76 days and lose between 4.3% to 32.1% of their body weight before dying.
Common male octopuses have been observed lasting between 79 to 188 days without food before dying.
Once reproduction is taken care of and assuming that the male octopus has survived the process, unable to feed, he will often drift in the water column, almost seeming to invite predators to end his life.
Female Octopuses (After the Female Octopus Lays Her Eggs)
The female octopus needs to survive long enough with her maternal instincts to tend her eggs.
While she looks after her brood without feeding, she will metabolize muscle tissue to use as food and lose significant amounts of body mass.
The brooding time the female needs to stay alive varies dramatically between species.
It can be up to six to seven months for the great Pacific octopus or as little as a few weeks for smaller tropical species.
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The rare deep-sea octopus Graneledone boreopacifica has been observed brooding eggs for a record 53 months, which is the most prolonged period known in the animal kingdom.
Are There Any Octopus That Don’t Die After Mating?
The Larger Pacific striped octopus (LPSO – currently undescribed by science) is found in tropical waters of the Eastern Pacific and displays some unusual behavior, including the ability for females to breed more than once in their lifetimes.
During mating, the LPSO has been observed to be considerably more gentle than many other species.
Male and female octopuses come together and appear to exercise extreme caution with their suckers and beaks so as not to harm one another.
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The female LPSO can spawn on multiple occasions over a continuous period of about six months.
The females watch over her eggs similarly to other octopus females until they hatch about eight months after being laid.
Female LPSOs continue to feed during this time and will accept new mates and subsequently lay additional egg batches.
What Happens if You Save an Octopus After Mating?
Can an octopus survive after mating? Apart from the LPSO, all octopuses are doomed to death once the optic gland has triggered senescence.
If you were to pluck a male octopus from the ocean and put it in a food-stocked aquarium after it had mated, the biological changes would still have occurred.
It wouldn’t feed, so it would die just like if you had left it in the wild.
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As we’ve already mentioned, the exception is if the optic gland is removed by surgery that allows the octopus to feed again for about six months before old age takes over.
So, saving an octopus from the evolved senescence process isn’t possible.
Conclusion
We’ve seen that the reason why do octopuses die after mating is because of the process of senescence that’s triggered by the optic gland.
Senescence is when the octopus becomes ready to reproduce, but it also triggers a loss of appetite, which dooms the octopus to starving.
The male dies soon after mating has taken place. That’s if they survive the process itself and don’t get eaten by the female.
Females will stay alive a while longer as they need to tend their eggs until they hatch.
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After the new octopus babies are born, the female will also die.
The reasons why octopuses die after mating are not known for sure. Scientists believe it may be to do with protecting the eggs and newborn octopus from cannibalization by the female. It may also be to prevent the overpopulation of octopuses in the environment.
Whatever the reason, we can undoubtedly say that octopus parents make the ultimate sacrifice for their kids!
British-born Dan has been a scuba instructor and guide in Egypt's Red Sea since 2010.
Dan loves inspiring safe, fun, and environmentally responsible diving and particularly enjoys the opportunity to dive with sharks or investigate local shipwrecks.
When not spending time underwater, Dan can usually be found biking and hiking in Sharm's desert surroundings.