The longest egg-brooding in the animal kingdom
Who wins the longest egg brooding in the animal kingdom? At 9 months, human gestation period seems already quite long. Elephants, with around 22 months, have the record of the longest gestation for a mammal. Even they are dwarfed by the egg-brooding of a small octopus living 1 400 meters bellow: Graneledone boreopacifica.
How a group of scientists observed the longest brooding 1 400 meters underwater?
That should be the question that keep you awake. As scuba divers, you are quite surprised and impressed when you recognize a fish underwater. You can recognize it because it has a hook stuck in its mouth (who has seen Captain Hook at Shark Cave lately) or it has a fin bitten off. That exactly what Dr Robinson and its team found and published in the review Plos One. An octopus was slowly leaving the muddy bank where it generally leaves for the general direction of hard bottom. The octopus had a scar and it made it easy to recognize.
Thanks to a remote submarine, the scientists of the Monterrey Aquarium were ready to follow that octopus into its very long brooding.
Taking care of your eggs for 53 months
Another octopus already had the record for the longest egg care, but Graneledone boreopacifica just blew it. Because they are in soft shell that allow the baby octopus to grow, the mother has to clean the eggs to let oxygen get in it and protect it from predator. For our brave deep octopus, the wait was long, it took 53 months for the eggs to hatch. The mother octopus did not move and did not fed. In fact, Dr Robinson could observe that skin of the octopus was changing and degrading with time. From a nice grey to ghosthy white you can see, it took a toll to the proud mother. In total the submarine did 18 dives to observe the progress.
After 4 years and a half, they found the hatched egg. The mother and the babies were no were to be found. As in other species, the scientists believed the mother died soon before the hatching. The male octopus, in general, dies after the reproduction.
Is it the longest brooding in the animal kingdom?
The best part of this story is the result that the Monterrey Aquarium got from that observation. It seems to prove that the size and brooding of eggs for octopus depends on the temperature. The cooler the water is, the longer are the eggs and longer is the brooding.
So what if we found an octopus that leaves deeper and in cooler water? Could there be an octopus with an even longer brooding? The best candidate that comes to mind is Casper the friendly octopus?
Living at 4 000 meters in water that can reach 1.5 Degree Celsius, they could have a greater brooding time. We have already observed them grabbing on a sponge and laying their eggs, but we don’t know yet what is their brooding time. For Graneledone boreopacifica, the temperature was around 3°C. We could imagine that Casper will be able to beat the record easily!