Octopuses are highly intelligent yet typically live for only one to five years.

The short lifespan of an octopus is a biological phenomenon known as semelparity, meaning they reproduce only once before dying. This process is controlled by the optic gland, which is similar to the pituitary gland in humans. After mating, this gland triggers a hormonal shift that shuts down the octopus's digestive system and leads to a rapid physical decline called senescence.During this period, female octopuses stop eating entirely to guard their eggs, sometimes for months at a time. For example, a Deep-sea Octopus (Graneledone boreopacifica) was observed by the Monterey Bay Aquarium Research Institute (MBARI) brooding its eggs for a record-breaking 4.5 years without eating. Once the eggs hatch, the mother's body has essentially consumed itself to provide the energy needed for protection.This 'live fast, die young' strategy allows octopuses to grow at an astonishing rate. A Giant Pacific Octopus can increase its body mass by 5% every day, reaching up to 100 pounds (45 kilograms) in just a few years. Researchers at institutions like the Marine Biological Laboratory in Woods Hole study these animals to understand why such intelligent creatures evolved with such limited longevity.The rapid aging process is thought to be an evolutionary trade-off that prevents overpopulation and ensures that only the fittest genes are passed on. Because they die so young, octopuses cannot pass knowledge down to their offspring through social learning. Every individual must learn how to hunt, camouflage, and navigate the ocean entirely on its own from birth.