Thousands of octopuses have been discovered gathering together to protect their eggs in an unusual phenomenon off the coast of Central California. This rare occurrence has puzzled scientists for years, but recent research may have finally shed light on the mystery. It turns out that the heat emanating from the base of an extinct underwater volcano contributes to faster hatching of the octopus eggs, providing benefits for both the parents and their offspring.
The researchers, including octopus biologist Janet Voight from the Field Museum of Natural History, published their findings in a study in Science Advances. They observed that the heated nest location reduced the average hatching time for the eggs by more than half. This accelerated hatching process offers a significant advantage by minimizing the risk of predation by snails, shrimp, and other predators.
The nesting site, aptly dubbed an octopus garden, was initially discovered in 2018 by researchers from the Monterey Bay National Marine Sanctuary and other institutions. Using an underwater remote vehicle, they were able to capture footage of nearly 6,000 octopuses huddled together over their eggs on rocks that were heated by the seeping water from the seafloor.
The sight was truly remarkable, with thousands of pearly-colored octopuses upside down, pushing away potential predators and meticulously caring for their eggs. The researchers monitored the site for three years, tracking the hatching cycle and the eventual deaths of the octopus mothers.
After the hatchlings come out of the nest and swim off immediately into the dark, the mothers, who never left their nest and never appeared to feed during nesting, soon die, explained James Barry, a biologist at the Monterey institute and co-author of the study.
The research team found that the eggs at this specific nesting site hatch in approximately 21 months, a significantly shorter duration compared to other deep-sea octopus eggs that usually take four years or more to hatch. This unexpected phenomenon can be attributed to the warmth provided by the hydrothermal seep, which seems to speed up the metabolic processes and embryonic development of the eggs.
Adi Khen, a marine biologist at the Scripps Institution of Oceanography, who was not involved in the study, noted that this discovery challenges the conventional understanding that colder water in deep-sea environments slows down metabolism and extends the lifespan of organisms.
The scientists involved in this research have expressed their excitement about the important role octopus gardens like this one may play in the deep sea ecosystem. They believe that these gatherings and their heat-providing benefits might be more widespread than previously known.
Mike Vecchione, a zoologist from the Smithsonian National Museum of Natural History, praised the painstaking efforts of the researchers in gathering such detailed data from such a remote location. He added, There’s still so much to discover in the deep sea.
The discovery of this unusual octopus gathering and the key role of heat from an extinct underwater volcano in promoting faster egg hatching has provided valuable insights into the lives of these solitary creatures. It also underscores the need for continued exploration and scientific study to better understand the mysteries of the deep sea.
