Talk about extreme parenting: Scientists have found a deep-sea octopus mama that faithfully guards the same clutch of eggs for an incredible 4½ years — a record.
“As far as we know, this is the longest brooding or gestation of any animal on the planet,” said Brad Seibel, an animal physiologist at the University of Rhode Island. “Elephants gestate for 20 to 21 months, and some deep-sea sharks carry their embryos around internally for a couple of years, but nothing is longer than this.”
The long brooding period represents the far end of an underwater parenting spectrum. On the opposite end lies the “broadcast spawn” strategy, when an animal releases hundreds of thousands of eggs into the water and hopes for the best. Most of those eggs and juveniles get gobbled up by predators, but because there are so many of them, a few do make it to adulthood.
The deep-sea octopus Graneledone boreopacifica, on the other hand, produces a relatively small number of eggs (between 155 and 165), and then watches over them until the babies inside are well developed and, therefore, more likely to survive.
What makes this ocotopus’ herculean act of parenting all the more amazing is that during those 4½ years that she is protecting her eggs, she does not appear to eat.
This lengthy brooding period was only discovered in the last few years when researchers from the Monterey Bay Aquarium Research Institute got lucky and located a Graneledone boreopacifica just weeks after she laid her eggs.
Their findings were published in a paper published Wednesday in PLOS One.
The research began in April 2007, when the team took a remotely operated vehicle (ROV) out for a spin in the Monterey Submarine Canyon and came across an isolated rocky outcropping on the ocean floor about 4,600 feet down.
Deep-sea octopuses need to find rocky slopes at the bottom of the ocean to which to attach their eggs, and scientists had seen octopuses guarding their eggs in this spot before. This time, however, the slope was octopus-free, although the researchers did notice an octopus moving over the sandy floor toward the hard surface.
When the ROV cruised past the same spot 38 days later, the team saw the same octopus (identified by a tell-tale scar on the webbing between her legs) was perched on the rocks, guarding a clutch of eggs.
On their last visit in September 2011, they found the milky white oblong egg sacs torn and empty, and the mama octopus gone.