Sea turtles lay their eggs and move on, birds will sit on their eggs until they hatch but no other known animal is quite like this octopus. Researchers at the Monterey Bay Aquarium Research Institute (MBARI) watched for a deep sea octopus guard her eggs for four-and-a-half years.

During that time, she did not move from the nest. She guarded and cleaned the eggs while eating little or nothing. According to researchers the octopus didn’t even show an interest in passing crab or shrimp unless they threatened the eggs.

For the last 25 years, researchers at MBARI have performed surveys of deep sea animals in the Monterey Canyon “Midwater 1”. In May, 2007 the team, led by Bruce Robinson noticed a new resident who had not been there in April.

A female octopus, Graneledone boreopacifica, was clinging to a rock ledge 4,600 feet below the oceans surface. In 18 surveys conducted over the next four-and-a-half years the octopus was in the same spot. Over time the researchers noticed the eggs which became translucent, with the young octopuses visibly developing inside.

Most female octopuses lay eggs only once and die shortly after the eggs hatch. Over time the octopus lost weight and her skin became pale and loose. In September 2011 when the researchers surveyed the site, she was gone but “the rock face she had occupied held the tattered remnants of empty egg capsules,” according to the paper published in PLOS ONE.

The MBARI team estimates that 160 eggs hatched. Because they spend so long developing in the eggs, the young Graneledone boreopacifica are able to care for themselves and hunt small prey from birth.
“The trade-off within the reproductive strategy of deep-living octopods is between the mother’s ability to endure a long brooding period and the competitiveness of her hatchlings. Graneledone boreopacifica produces hatchlings that are very highly developed, which gives them the advantage of a high potential for survival,” said the researchers, in a statement.

Although 54 months is a record, the researchers point out that eggs develop more slowly in cold water such as that found in the deep ocean. One type of shrimp known to inhabit the same canyon will carry its eggs for 20 months.