Most female octopuses die shortly after their eggs hatch. This single reproductive effort is a strategy known as semelparity, which translates to “once-begetting” in Latin. Semelparity means the organism dedicates all its available energy to one reproductive event. For the majority of octopuses, this results in a programmed, terminal decline immediately following the successful laying of eggs.
The Ultimate Sacrifice: Brooding Behavior
The female’s physical decline begins with an intensive focus on her clutch of eggs, a period known as brooding. She anchors the eggs inside a protected den and rarely leaves this shelter during development. The duration can last for months or even years, depending on the species and water temperature. The mother maintains the health of the eggs by using her arms to clean them of debris and blowing water from her siphon to keep them aerated.
This vigil requires self-sacrifice, as the female ceases to hunt or feed entirely. During this extended period of self-starvation, her body catabolizes its own tissues for energy, leading to severe muscle atrophy and significant weight loss. In the final days, physical deterioration is accompanied by behavioral changes, such as becoming listless, losing skin coloration, and engaging in self-mutilation. The combination of complete starvation and physical exhaustion ensures the mother’s death occurs around the time her offspring emerge.
The Biological Trigger for Self-Destruction
While self-starvation is the immediate cause of death, the process is actively controlled by an internal biological mechanism. The trigger for this programmed decline resides in the optic gland, a small neuroendocrine structure located between the eyes. Once the female mates and lays her eggs, the optic gland initiates a cascade of hormonal signals that act as a “self-destruct” system.
The activated optic gland upregulates and downregulates multiple signaling pathways, including those related to catecholamines, steroids, insulin, and feeding peptides. Research shows the optic gland begins producing high levels of 7-dehydrocholesterol (7-DHC) and other steroid-like compounds. These specific cholesterol metabolites are thought to be toxic at high concentrations, leading to the rapid deterioration of the nervous system and tissues.
The resulting hormonal signals suppress appetite, accelerate cellular aging, and contribute to the self-destructive behaviors observed in the mother. In early experiments, researchers surgically removed the optic gland from brooding females. These mothers abandoned their eggs, resumed feeding, and lived for months longer, demonstrating the gland’s direct control over the death sequence.
Exceptions to the Rule
The phenomenon of programmed death is widespread across the octopus order, but the reproductive strategy is not universal. Some species demonstrate iteroparity, meaning they can breed and lay eggs multiple times over their lifespan. The larger Pacific striped octopus (Octopus chierchiae) is a notable example of this exception.
Unlike semelparous species, female larger Pacific striped octopuses continue to feed, mate, and lay multiple clutches of eggs continuously over several months. They have been observed laying eggs for up to six months while maintaining their health and social behaviors. Furthermore, deep-sea species, such as Graneledone boreopacifica, brood their eggs for extraordinarily long periods, up to four and a half years, before succumbing to death.