The Sad and Disturbing Reason Why Octopuses Torture Themselves

Octopuses are amazingly intelligent creatures and are so intriguing that no one knew why they torture themselves, until now.

Isabel Cara


The reproductive behavior of octopuses is an enigma, after the eggs approach hatching and just as they are about to begin their life, the mother descends into a labyrinth of destruction by choice. They begin to beat themselves against rocks and even mutilate themselves to death. Biologists have been intrigued by this behavior, and although they had clues, there was no more in-depth explanation; until now. It seems they finally solved the riddle of why octopuses torture themselves.

Programmed to Die?

Mating among octopuses is completely different from what we know of other marine species. They practice a kind of external fertilization, where the males deposit their spermatophores directly into a tubular funnel that the females then use to breathe. Or they simply deliver them directly to the female, who accepts them with one of her right tentacles (researchers do not know why). The females then care for the eggs until they are about to hatch. Once the tiny octopods are ready to hatch, the females simply commit suicide. By hitting themselves against rocks, tearing their skin, or even eating pieces of their tentacles, the females die.

In 1977 Jerome Wodinsky of Brandeis University found that the mechanism behind this bizarre self-destructive behavior lies in the optic glands, a set of glands near the eyes of octopuses, which is the equivalent of the pituitary gland in humans. In theory, if these glands were cut, the mother octopus would not abandon her eggs and would continue with her life. However, although it is known in which region this mechanism lies, it was not known why it occurs.


A Host of Changes in the Octopus Organism

Yan Wang of the University of Washington is interested in discovering what is behind the self-destructive mechanism of octopuses. That is why he took Wodisnky’s research as a basis and analyzed the processes in the optic glands. He discovered the chemicals behind the deadly frenzy that drives females to suicide. From an ethological point of view, the self-inflicted death may be due to a way of maintaining the survival of the species, since octopuses are cannibals. In that sense, if the older generations thrived longer, they would take it upon themselves to eat the young.

But by analyzing the chemicals, they reveal exactly what is going on in their bodies. After the females lay their eggs, three chemical changes occur in their bodies. There is an increase in pregnenolone and progesterone, hormones associated with reproduction in a large number of animals. Levels of a cholesterol building block called 7-dehydrocholesterol, or 7-DHC, also rise. Humans also produce 7-DHC in the process of cholesterol generation, but we do not keep the compound long in our system, as it is toxic. In fact, babies born with Smith-Lemli-Opitz syndrome, a genetic disorder that prevents the elimination of 7-DHC, suffer from intellectual problems, behavioral issues, including self-injury, and physical anomalies such as extra fingers, toes, and cleft palate.

After egg laying, female octopuses also produce more bile acids, which in humans are produced by the liver. The lethal combination leads the females to undergo a series of changes in their bodies that are likely to lead to self-destruction.

Story written in Spanish by Alejandra Martínez in Ecoosfera