How Long Do Octopuses Live? Why Most Die After Breeding

Octopus lifespans by species

Temperature makes a big difference. In warm water, octopuses grow fast, mature early and die young. In cold water, everything slows down, including egg development, so octopuses in the deep sea or the far north tend to live longer. The common octopus of the Mediterranean is a typical fast-living species, growing from a tiny drifting hatchling to an adult of 1–3 kg (2–7 lb) in about a year.

For comparison, their shelled cousin the chambered nautilus can live 20 years or more, which shows that a short life is not forced on all cephalopods.

Why do octopuses die after breeding?

Octopuses are semelparous, a term for animals that reproduce once in a lifetime and then die, like Pacific salmon. After breeding, they enter a final stage called senescence, a rapid breakdown of the body that lasts from weeks to a few months.

The signs are similar in males and females. The octopus stops eating and loses weight, its skin develops pale patches and sores that do not heal, the skin around its eyes shrinks back, and it may wander in the open in an uncoordinated way. In the giant Pacific octopus, this stage usually lasts one to two months. Many males are eaten by predators during this time, while females die of starvation and exhaustion beside their eggs.

The optic gland: an octopus timer

The decline is controlled by the optic glands, two small glands between the brain and the large optic lobes, often compared to the pituitary gland in vertebrates. They release hormones that trigger sexual maturity and, after breeding, the final decline.

In a classic experiment published in 1977, a researcher removed both optic glands from female Caribbean two-spot octopuses after they had laid their eggs. The females abandoned their eggs, started eating again, grew, and lived for months longer than untreated mothers. Research on the California two-spot octopus since 2018 has linked the decline to major changes in the optic gland’s chemistry, including the way it processes cholesterol and steroid hormones.

A mother’s last months

The female octopus’s final act is her most demanding. She finds a sheltered den, lays her eggs in strings attached to the roof, and stays with them day and night. She cleans them with her arm tips, blows fresh, oxygen-rich water over them, and drives off crabs and fish that try to eat them.

A female common octopus lays 100,000–500,000 eggs and broods them for about one to five months, depending on the water temperature. A giant Pacific octopus lays about 120,000–400,000 eggs and broods them for about six months, longer in very cold water. In most species she eats little or nothing during this time, and she dies soon after the last young hatch.

There are exceptions. The larger Pacific striped octopus, found off Central America, can mate many times and lay several clutches over months while continuing to feed, which is very unusual among octopuses.

The record: a deep-sea mother that brooded for 4.5 years

The longest-known brooding period of any animal belongs to a deep-sea octopus. In the spring of 2007, researchers from the Monterey Bay Aquarium Research Institute, using a remotely operated vehicle, saw a female Graneledone boreopacifica settle on a rocky outcrop about 1,400 m (4,600 ft) deep in Monterey Canyon, off central California, and begin guarding a clutch of eggs.

They returned to the site 18 times over the next four and a half years. Each time she was in the same place, her skin turned from purplish to pale, almost white, and she was never seen to feed. When the team visited in late 2011, she was gone and the eggs had hatched. The brooding had lasted 53 months, and because she must have grown for years before laying, her full lifespan was even longer.

Other deep-sea octopuses use a shortcut. Off central California, thousands of pearl octopuses gather to brood near springs of warm water seeping from the seafloor about 3,200 m (10,500 ft) deep. A 2023 study found that the warmth speeds up their eggs, which hatch in less than two years instead of the many years expected in near-freezing water.

Why do octopuses live such short lives?

Scientists are still debating this. A leading idea links it to the loss of the shell. Without armor, octopuses are eaten by many predators, so few would survive to old age anyway. Under those conditions, evolution favors growing fast and putting everything into one huge batch of eggs, rather than surviving to breed again.

The same pressure may help explain their intelligence: animals that must find food and avoid enemies without a shell benefit from learning fast within a short life. Another suggestion is that dying after breeding stops adults from competing with, or eating, their own young, since octopuses are often cannibals. None of these ideas has been proven, and they are not mutually exclusive.

Octopuses are a striking contrast with animals at the other end of the scale, described in our list of the longest-living animals.