A team of deep-sea scientists has made a mother of a discovery. In recent research, they describe the discovery of a female squid exhibiting unusual behavior for its species: protecting and carrying around a clutch of giant eggs. The mama squid likely belongs to a previously unknown species of cephalopod, the researchers have determined.
The discovery was actually made in 2015 by scientists from the Monterey Bay Aquarium Research Institute (MBARI), the GEOMAR Helmholtz Center for Ocean Research Kiel in Germany and the University of South Florida. They were using their robots in the deep basins of the Gulf of California, hoping to learn more about how animals live in the area’s low-oxygen zones, when they came across this unexpected sight.
The pink squid was observed at a depth of 2566 meters, its tentacles carefully holding its eggs. Cuttlefish usually lay their eggs in clumps attached to the seabed or floating along the water. But some species exhibit this more protective behavior, known as brooding. Although breeding has been observed in deep-sea squid before, it has never quite looked like this. For starters, the squid’s eggs were relatively large, measuring about half an inch in diameter, while the eggs of other known breeding deep-sea squids are about half that size. The squid also only carried about 30 to 40 eggs, compared to the sometimes thousands of eggs seen in other species.
After further studying their images and comparing them to other squid sightings, the team concluded that they had indeed discovered a previously unknown species – one that likely belongs to the family Gonatidae, also known as arm hook squids. The team’s research detailing their findings was published in the news last month Ecology; MBARI too issued posted a short video clip of the squid on his YouTube channel last week.
“The deep sea is the largest living space on earth and there is still much to discover. Our unexpected encounter with a squid hatching giant eggs caught the attention of everyone in the ship’s control room,” said Steven Haddock, senior scientist at MBARI and principal investigator on the 2015 expedition, in a rack released by MBARI. “This remarkable observation highlights the diversity of ways in which animals adapt to the unique challenges of life in the deep.”
Brooding is a drastic strategy for a squid because the mother will not eat while protecting her eggs and decay quickly after they hatch. And this newly discovered squid species could have an even tougher time than others, as their young can take one to four years to emerge given the larger size of the eggs, the researchers say (the current breeding record appears for a certain species of deep-sea octopus is 4.5 years). But incubation increases the chance that the eggs will survive. These squid may have evolved to hatch giant eggs as a new twist on this adaptation, the researchers argue, with the stable resources of the deep sea perhaps allowing them to invest more in the individual survival of their offspring.
Either way, as is often the case in science, this discovery will give researchers more mysteries to try to solve.
“Advanced underwater robots are helping us better understand the lives of deepwater squids and revealing fascinating new information about their biology and behavior. Every new observation is a new piece of the puzzle,” said lead author Henk-Jan Hoving, a former MBARI fellow who now leads the deep-sea biology working group at GEOMAR, in a statement.