Scientists on Wednesday described how the female of an octopus species that dwells below the sea surface spends about 4.5 years brooding her eggs, protecting them vigilantly until they hatch. It is the longest known egg-brooding period for any animal, they wrote in the scientific journal PLOS ONE. The scientists used a remote-controlled submarine to monitor the deep-sea species, called Graneledone boreopacifica, off the coast of central California.
It’s extraordinary. It’s amazing. We’re still astonished ourselves by what we saw.
Bruce Robison, deep-sea ecologist at the Monterey Bay Aquarium Research Institute in California
Scientists tracked one female, recognizable by its distinctive scars, that clung to a vertical rock face near the floor of a canyon about 1,400 metres under the surface, keeping the roughly 160 translucent eggs free of debris and silt, and chasing off predators. This mother octopus never left the oblong-shaped eggs and was never seen eating anything. The octopus progressively lost weight and its skin became pale and loose. The researchers monitored the octopus during 18 dives over 53 months from May 2007 to September 2011.
She was protecting her eggs from predators, and they are abundant … She was also keeping the eggs free from sediment and was ventilating them.