Octopus guarded her eggs for four and a half years
- Octomom guarded about 160 eggs for four and a half years, the longest brooding period known.
- Scientists can describe her vigil, but don’t know why it lasted so long, or what she experienced.
After four and a half years guarding her eggs, Octomom was gone. Deep-sea scientist Bruce Robison said his team found torn egg cases and hatchlings nearby. He suspected a scavenger had eaten her, and believed she stayed until the last egg hatched.
Robison’s team first saw the purple-gray octopus in April 2007, less than a mile down in Monterey Canyon. A month later, they found her curled around about 160 eggs. Researchers returned when they could, sometimes months apart, and found her still there.
She cleaned and guarded the clutch, even as her body grew pale and gaunt and her eyes clouded. Robison said she refused crab legs the team offered; when crabs circled the eggs, she defended them. The team never saw a predator take an egg. Her vigil is the longest brooding period known on Earth, according to Robison.
Evolutionary neuroscientist Yan Wong said changes involving the octopus’s optic glands help females stop feeding and continue guarding eggs. That may help explain how Octomom endured, but not why her species’ brooding takes years. Robison and Wong suggested cold water could slow development, or that deep-sea hatchlings may need more time to develop. They have observed no other member of her species through this process, so they don’t know whether her vigil was typical.
Researchers could watch Octomom’s behavior and see her body weaken, but not know what she experienced. Calling her a devoted or heroic mother adds a human interpretation to a remarkable stretch of animal behavior.
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Octomom • Oct 23
- Bruce Robison’s team first saw Octomom in April 2007, using a remotely operated sub from the Western Flyer in Monterey Canyon. The team was less than a mile down, where darkness, bioluminescent animals, and underwater sounds defined the scene.
- Robison described Octomom as a purple-gray octopus with a cantaloupe-sized mantle, stretchy arms, and distinctive scars. A month after the first sighting, the team found her covering a clutch of 160 eggs; researchers knew little about the brooding period of deep-sea octopus species.
- Robison said Octomom guarded and cleaned her eggs while crabs and shrimp prowled the rock. She refused crab legs the team offered, later killed crabs that circled her, and the researchers never saw a predator take an egg.
- Robison’s team watched Octomom brood for four and a half years, the longest brooding period known on Earth. She grew pale and gaunt, developed cloudy eyes, and appeared to waste away while remaining on the eggs.
- Yan Wong said most octopuses stop feeding while brooding, and females die after reproducing. Shallow-water species she studied typically live about a year and brood for roughly a month; Octomom’s deep-sea species may live longer, but its lifespan is unknown.
- Bruce Robison said the team found Octomom gone after four and a half years, with torn egg cases on the rock and hatchlings nearby. He suspected a scavenger consumed her and believed she stayed until the last egg hatched.
- Robison and Wong offered two possible reasons for the unusually long brooding period: cold deep-sea conditions may slow development, or the harsh environment may favor more developed hatchlings. They stressed that Octomom could be typical for her species or an exceptional case; no one had observed another.
- The hosts read Octomom’s endurance as a model of patience and protection, while also questioning that human story: no one knows what the octopus experienced during years alone in the dark. The animal’s behavior is observable, but its subjective experience remains unknown.
Also discussed on this episode: (4)
Biology (4)
- Wong described octopus reproduction as a short mating encounter: the male transfers a sperm packet into the female’s mantle using one arm. The female can determine when to fertilize her eggs, then lays them in a protected spot and remains until they hatch.
- An aquarium observer recounted seeing a male and female octopus turn red, embrace with their suckers, and remain together afterward; both sometimes turned white, a relaxed color. The transcript also identifies the observer as the author of The Soul of an Octopus and roughly 29 other animal books.
- Wong linked the brooding transformation to the optic glands, small structures between the eyes. As other bodily processes shut down, the glands trigger chemical changes, including steroids and insulin, that help an octopus survive without food; Wong said the mechanism is still being pieced together.
- The report used events above the seafloor to mark Octomom’s years of brooding: the iPhone’s US release in 2007, the economic crash and Obama’s election in 2008, and the Chilean miners’ rescue in 2010. It also mentioned major events in 2009 and 2011, including Usain Bolt’s record and the Arab Spring.