Gruesome Octopus Death Spiral: Bizarre Self-Mutilation in Mothers Linked to Cholesterol

 A tragic spiral of death for the octopus results from changes in cholesterol production. 

Recent research reveals striking similarities in the biology of steroid hormones between humans, mice, and cephalopods, which when disrupted can have devastating effects.

Octopuses frequently die tragically despite their remarkable intelligence and supernatural abilities to change color and regenerate limbs. A mother octopus stops eating and wastes away after laying eggs; She has passed away by the time the eggs hatch. Some captive females even appear to deliberately accelerate this process by mutilating themselves and twisting their arms into a tangled mess.

The optic gland, which is a mammalian organ similar to the pituitary gland, appears to be the cause of this bizarre maternal behavior. A new study by researchers from the University of Chicago, the University of Washington, and the University of Illinois at Chicago (UIC) reveals that the optic gland in maternal octopuses undergoes a massive shift in cholesterol metabolism, resulting in dramatic changes in the steroid hormones produced. The exact mechanism by which this gland sparked the horrific death spiral has been a mystery for years.

The authors of the study believe that this reveals important similarities in the functions of these steroids across the animal kingdom, in soft-bodied cephalopods and vertebrates alike. Alterations in cholesterol metabolism in other animals, including humans, can have serious consequences on longevity and behavior.

Z Y-A N Wang, P H D, an Assistant Professor of Psychology and Biology at the University of Washington and the study's lead author, stated, "We know cholesterol is important from a dietary perspective, as well as within different signaling systems in the body". Although it is involved in everything from the production of stress hormones to the flexibility of cell membranes, its inclusion in this life cycle process was a big surprise

Self-destruct hormones

Jerome W O D-I N S K Y, a psychologist at Brandeis University, demonstrated in 1977 that Caribbean two-spotted octopus mothers (Octopus H U M-E L-I N C K-I) abandoned their clutch of eggs, resumed feeding, and lived for months longer if he removed the optic gland.

The RNA transcriptome of the optic gland from several California two-spotted octopuses (Octopus H U M-E L-I N C K-I) at various stages of their maternal decline was sequenced in 2018 by Wang, then a graduate student at the University of Chicago, and Clifton R-A G S D-A L-E, P H D, Professor of Neurobiology at UChicago. Wang and R-A G S D-A L-E, P H D went one step further in their research in the new paper, which was published on May 12, 2022, in the journal Current Biology.

In it, they looked at the chemicals that the optic gland in the mother octopus produces. They collaborated with UIC Associate Professor of Chemistry Stephanie C O L O G N-A, P H D, and former UIC graduate student Melissa P-E R G-A N D-E, who specializes in mass spectrometry, a method for analyzing the chemical composition of biological samples

Tiny and underappreciated

We now have at least three seemingly separate routes to steroid hormones, which may explain the variety of effects these animals exhibit. Before joining the faculty at the University of Washington, Wang will complete her grassroots fellowship this summer at the Marine Biological Laboratory (MBL), which is affiliated with the University of Chicago. The lesser Pacific striped octopus (Octopus C H-I E R C H-IA-E), a new model animal, is a major draw for MBL's extensive cephalopod research program