A deep-sea octopus broke records by nourishing its eggs for a whopping 53 months.
Researchers used a remote-controlled underwater vehicle to observe the behavior of the elusive deep-sea octopus. They observed a female protect and fertilize her eggs for 4.5 years; octopi living at shallower depths care for their eggs for between one and three months, PLOS reported.
"In the cold, dark waters of the deep ocean, metabolic processes are often slower than their counterparts at shallower depths. Extrapolations from data on shallow-water octopus species suggest that lower temperatures would prolong embryonic development periods," the researchers reported in their study abstract.
The research team observed the deep-sea octopus first in 2007 at a depth of about 1,400 meters. When they returned in May 2007 the same octopus was seen on a rock guarding a clutch of eggs. The researchers returned to the site over 18 times over the course of 53 months to see how the eggs developed. Every time the team returned to the site the octopus was holding onto the vertical rock face and shielding her eggs. Since the eggs continued to grow throughout the observation period the researchers are confident the female was holding onto the same clutch of eggs.
About 160 eggs hatched between September and October of 2011; this is the longest egg-brooding time ever reported for an animal of any species. The findings were based on the observation of only one animal, so the researchers warn the findings may not be unique to all deep-see species.
"These surprising results emphasize the importance of parental care in producing well-developed offspring that can cope with the rigors of the deep-sea habitat. Because the brooding period is temperature dependent, the results also provide a caution about the potential consequences of our changing climate," Bruce Robison from Monterey Bay Aquarium Research Institute said.
