what happens when a mother octopus lays her eggs? She stops eating and weakens until she wastes away. By the time the eggs hatch, she is dead. Some females in captivity intentionally accelerate this process by mutilating themselves. Why? The mystery of the suicidal octopus seems to be finally solved.
The source of this strange maternal behavior appears to be the optic gland. It is an organ similar to the pituitary gland in mammals. Researchers at the University of Chicago, Washington and Illinois studied it. The optic gland in maternal octopuses undergoes a massive change. How? In cholesterol metabolism. Thus, there are drastic changes in the steroid hormones produced. The alterations can have serious consequences on longevity and behavior.
“Cholesterol is important for different signaling systems in the body,” says Z. Yan Wang. He is senior author of the study. “It is involved in the production of stress hormones. It was a big surprise to see its role in this life-cycle process,” he adds.
The paper was published this week in ‘Current Biology’. Chemicals produced by the optic gland of the mother octopus were analyzed. The new research shows that the maternal optic gland undergoes dramatic changes. It produces more pregnenolone and progesterone, as well as 7-DHC during stages of decline.
Elevated levels of 7-DHC are toxic to humans. It is the hallmark of a genetic disorder called Smith-Lemli-Opitz syndrome (SLOS). Children with the disorder suffer severe developmental and behavioral consequences. Including repetitive self-injury reminiscent of octopus behaviors.
The unknown of suicidal octopuses would be explained by that imbalance. Disrupting cholesterol production has serious consequences.
“They seem to go crazy just before they die,” they claim. The Pacific lesser striped octopus does not self-destruct after reproducing. So scientists plan to examine the optic glands of these animals. They must compare them to find out what makes them different from their relatives.