The animal kingdom is full of hard-working mothers, but one really takes her commitment to her offsprings’ survival to an unprecedented level.
One deep-sea octopus has been found to brood its eggs for a total of four and a half years (53 months)—much longer than any other known species on earth, and three times longer than the brooding period of the previously held record, which stands at 14 months, MBARI reported.
The sacrifice by a mother octopus of the Graneledone boreopacifica species, one of the most common deep-sea octopuses in the Northeastern Pacific, that researchers at the Monterey Bay Aquarium Research Institute (MBARI) observed over time was unthinkable.
Usually, octopuses reproduce only once during a lifetime, and they will protect the eggs until they hatch, after which the mother dies. In shallow water, the breeding period usually lasts one to three months.
Researchers contrast the situation to deep water, where the habitat is “cold, dark, and dangerous,” which means octopus babies need to be better prepared to cope with the harsher conditions upon hatching.
“While most experts assume that octopus breeding in deep water might be longer than a few months, no one had ever been able to measure it from the beginning to the end,” a video from MBARI notes. “And no one was prepared for the answer when we finally found it.”
In May 2007, MBARI researchers chanced upon a female octopus clinging to a rocky ledge about 4,600 feet (1,400 meters) below the ocean surface at Monterey Bay on the coast of California.
Over the next four and a half years, they visited the site 18 times. They observed the eggs grew larger while the mother gradually lost weight, her skin became loose and pale, and her eyes became cloudy.
They never saw the mother abandon her eggs or eat in the four years—not even the small crabs and shrimp that came by, as long as they did not disturb her eggs.
“One year, two years, three years—four, and still she hung in there,” they noted.
The last time they saw the dedicated mom was in September 2011. She was gone a month later. In a 2014 paper in the Public Library of Science (PLOS ONE), they wrote, “the rock face she had occupied held the tattered remnants of empty egg capsules.”
They estimated, after counting the egg capsule remnants, that the mom had 160 babies under her care.
“The last time we flew by, we spotted several very young octopuses beginning their lives on the same rock where their mother had persevered to ensure that they had the best chance of survival.”