Mysterious deep-sea 'mother squid' is spotted clutching dozens of giant eggs more than 1,800ft below the Pacific Ocean
An odd deep-sea squid, captured over 1800 feet below sea level by a submersible drone, is now believed to be a new species after nearly a decade of analysis.
Marine biologists first took note of the mother squid — now officially described as part of the family Gonatidae — in the Gulf of California off the Baja coast, where they caught it cradling eggs that were twice as large as any other seen before.
Typically deep-sea squid produce thousands of tiny eggs, as many as 3,000 all at once, but the new species was spotted holding and protecting only about 30 to 40 much larger eggs instead.
The researchers suspect a lack of predators in the deep sea, or possibly a more stable food supply, allowed this squid to evolve reproductive habits that devoted more resources to less eggs, rather than the shotgun approach of many tiny eggs.
An odd deep-sea squid, videotaped over 1800 feet below sea level via a submersible drone, is now believed to be a new species after nearly a decade of analysis. Above, a clip from that 2015 video of the deep-sea squid, described as a possible new species in the family Gonatidae
Typically deep-sea squid produce up to 3,000 much tinier eggs, in what experts called a 'bet-hedging' strategy that these creatures evolved to increase their species' chances of survival. The new squid (above) was spotted with only about 30 to 40 much larger eggs instead
The weird 2015 encounter led to a nine-year investigation by scientists in the US and Germany, who described the 'giant size of the eggs' as 'unprecedented.'
'Our unexpected encounter with a squid brooding giant eggs,' senior scientist Steven Haddock with California's Monterey Bay Aquarium Research Institute (MBARI) told reporters, 'caught the attention of everyone in the ship's control room.'
All previous deep-sea squids in this Gonatidae or Gonatus family have been recorded as reproducing via eggs no bigger than about a quarter of an inch (six millimeters).
The scientists called this more traditional squid approach of many tiny eggs a 'bet-hedging' strategy that the creatures evolved to increase their species' chances of survival in parts of the ocean where predators eat baby squid and their eggs.
But the 2015 mother squid was brooding with eggs nearly twice that size wrapped within her protective tentacles, estimated to be about half an inch (11.6 millimeters) in diameter.
The unexplained difference put scientists on the hunt for a good evolutionary reason why any deep-sea squid might come to reproduce this way.
'Our unexpected encounter with a squid brooding giant eggs,' one scientist with California's Monterey Bay Aquarium Research Institute told reporters, 'caught the attention of everyone in the ship's control room.' Above a close-up the eggs, which are about a half inch in diameter
All previous deep-sea squids in this Gonatidae or Gonatus family have been recorded as reproducing via eggs no bigger than about a quarter of an inch (six millimeters). Above, the squid Bathyteuthis berryi documented with a more typical brood of tinier squid eggs
'This remarkable sighting underscores the diversity of ways that animals adapt to the unique challenges of living in the deep,' according to Haddock at MBARI, who served as the chief scientist on the expedition that first video-taped the squid.
Data drawn from other marine biologists' research into the gestation period of squid eggs only deepened the mystery.
Based on the frigid ocean temperatures involved, and the sizes of other deep-sea squids with well-documented 'egg development rates,' the researchers estimated that the eggs of this new Gonatidae squid may take up to four years to develop.
'Brooding takes a lot out of a mother squid,' Hoving said in a statement from MBARI. 'She won't eat while carrying her eggs and ultimately dies after her eggs hatch.'
Above, a mother black-eyed squid (Gonatus onyx) brooding a much larger set of the more typical, and much tinier squid eggs
'But her sacrifice improves the chances that her offspring will survive,' noted Hoving, who now now leads the deep-sea biology working group at GEOMAR - Helmholtz Centre for Ocean Research Kiel in Germany.
'It's just one of the many remarkable adaptations that may help cephalopods [the technical term for squid and octopus species] to survive in the deep sea.'
A years long period of a mother squid caring for her eggs, with this level of sacrifice and resolve, would make this species an incredible outlier compared to other squid.
'If the brooding time is indeed longer than one year,' the research team wrote in their new study published in the journal Ecology, 'it lasts longer than the complete life cycle of most shallow water and coastal cephalopods [squid and octopus alike].'
Right now the researchers suspect this squid evolved to produce fewer and larger eggs, because its isolated, deep-sea ecosystem is light on baby squid predators.
'Brooding takes a lot out of a mother squid,' the new study's lead author said in a statement. 'She won't eat while carrying her eggs and ultimately dies after her eggs hatch'
Two species of deep-sea octopus, the warty deep-sea octopus (Graneledone sp.) and the pearl octopus (Muusoctopus robustus), also lay larger than normal eggs.
The fact that this is a trend in deep-sea regions, the team noted, might suggest that 'more stable and predictable conditions' in the deep allow these creatures to metaphorically put all of their eggs in one basket.
'Giant eggs may be more beneficial,' the team wrote in a statement, 'allowing for higher investment in fewer offspring that have a better chance of survival.'
The new study — a collaboration between MBARI in California, GEOMAR in Germany, and the University of Florida — hopes to collect more specimens to more robustly confirm this squid is definitively a new species.
Despite the crucial role that deep-sea squid play in the wider ocean food chain, and even the commercial fishing industry, very little about these creatures is currently well understood by marine science.
Deep-sea squid eat small fish and invertebrates and then, in turn, become food for commercially important fishes like tunas, swordfish, and billfishes. But their lifecycle and variety are still large open questions, the researchers said.
'Advanced underwater robots are helping us better understand the lives of deep-water squids, revealing fascinating new information about their biology and behavior,' according to Hoving.
'But we still have a lot to learn about the squid that live in the deep,' he added.
'The deep sea is the largest living space on Earth,' Haddock at MBARI added, 'and there is a lot left to be discovered.'
