Some would say there is no sweeter image than that of a new mother cradling her cooing baby. Today I want to share an even more beautiful photo with you: a new mother cradling 30 to 40 of her children, who are still eggs, in her crocheted and suction cup-covered arms. To make it even better, it’s a video, and not even a vertical, front-facing one!
The squid mother below was filmed in 2015 by researchers at the Monterey Bay Aquarium Research Institute piloting the remotely operated vehicle Doctor Ricketts, named after a famous scientist who had 15 species of animals and a nightclub named after him. The researchers dropped the ROV into the Gulf of California to discover how many creatures live in the deep parts of the ocean with extremely low oxygen levels. Just over 8,000 feet below the surface, a large red squid floated into view, holding several dozen eggs in her meaty arms.
Most squids have a much more carefree approach to childcare, i.e. they lay their eggs and die immediately. As such, it is often difficult for scientists to track where these eggs go, beyond the mouths of hungry predators. Some squid anchor their eggs to the seabed. Some jumbo squids lay translucent masses containing as many as 90,000 eggs that float, neutrally buoyant, in open water. But deep-sea squids have a strategy all their own. Some hatch their eggs and carry their eggs in large sheets resembling Hong Kong egg waffles as they drift in the dark.
MBARI scientists have observed a number of other species of deep-sea squid hatching their eggs over 37 years of research. They observed several black-eyed squid Gonatus onyx he holds a wavy balloon with small eggs, which the squid carries using the hooks on its arm. And they filmed squids of this genus Bathyteuthis grasping hundreds of tiny, translucent eggs in a curtain-like sheet. These brooding squids cannot eat while breeding, so they maintain their energy reserves until their eggs hatch and they are free to die.
The newly filmed squid appears to be a new species in the family Gonatidae, or arm hook squids. They are named for the many hooks on their arms, which are actually modified suckers, and larger hooks on their two long tentacles. The researchers were struck by how large the new squid’s eggs were: each almost half a centimeter in diameter, twice as large as previous observations of breeding animals. Gonatus squid and the largest recorded squid. And while others Gonatus Cuttlefish bore skins containing up to 3,000 eggs, but this mother had only 30 to 40.
Laying thousands of eggs can be a good bet for shallow-water squids that live in unpredictable environments with variable amounts of food and predators. But the researchers suggest that a strategy of investing more time and care in fewer eggs could pay off in the relatively stable environment of the deep sea. “Her sacrifice increases the chances that her descendants will survive. It is just one of many remarkable adaptations that could help cephalopods survive in the deep sea,” says Henk-Jan Hoving, a researcher leading the deep-sea biology working group at GEOMAR. in Kiel, Germany, and conducted this research while at MBARI, said the deep-sea octopus Graneledon Boreopacifica relies on this strategy to an extreme degree and has been breeding its eggs for more than four years.
But larger eggs take longer to develop, and the researchers predict that this squid’s eggs will take at least 1.4 years to develop into squids. This timeline is remarkable not only because of the effort it requires from mother squids, but also because it exceeds the lifespan of most cephalopods that live in shallow or coastal waters. The researchers suggest that squids can only perform such a vulnerable breeding action in these oxygen-poor areas of the ocean, where predators may be scarcer. Either way, it takes a long time to stay afloat in the depths while doing your best to avoid being eaten.
When this mother squid was filmed in 2015, her eggs would have hatched long ago, causing her to die and sink to the bottom of the Gulf of California. Somewhere in the gulf, a deep basin called the Cerralvo Trough has become an unofficial squid graveyard, where the carcasses of mother squids and the remains of their egg leaves burrow in the darkness to feed these even deeper creatures. In 2012, MBARI researchers recorded a fall of dead squid and egg skins that had become a feast for ratfish, acorn worms, brittle stars, sea cucumbers, crustaceans and starfish. It seems the mothers all died at the same time, dropping their babies into the depths as they sank together until the ratfish ripped off their tentacles for a snack. And isn’t that a beautiful image!