Deep-Sea Squid Caught in Rare Video Carrying Thousands of Eggs At Over 4,000 Feet Below Sea Level

A rare video taken 56 miles off the coast of California documents caught the unique brooding behavior of deep-sea squid.

Brooding in animal production refers to the care needed after eggs are laid to ensure the health and survival of the animal's offspring. It requires a significant sacrifice for mothers, especially for the rarely seen squid who, carrying her eggs, would not be able to feed nor make quick escapes.

Rare Sighting Shows Deep Sea Squid Brooding off California

At 4,560 feet below the surface of the sea, a remotely operated vehicle captured a unique video of a bright red deep-sea squid carrying a gelatinous string of hundreds of eggs off the coast of California. According to Science Alert, the footage of the unknown species is the second time scientists have seen the squid genus, Bathuteuthis, exhibiting unique brooding behavior.

The first time the unique brooding behavior was spotted was in 2005 when a Bathteuthis berryi was seen holding on to 360 eggs.

Despite the squid appearing colossal alongside its eggs, the species' main part, the mantle, reaches only three inches in length. This type of squid can be found across the globe and typically feed on krill.

Most females of the species will reproduce by depositing their egg cases on the ocean floor or releasing the eggs in a gelatinous mass that flows and drifts in open waters. According to Science Friday, squids typically do not brood their eggs and generally die soon after laying. Hence, the footage of a squid holding on to its eggs is rare in and of itself.

Rare Look Into Squid Brooding

As of now, only three squid species have been observed to brood their eggs, although experts are still unsure why they suspect that it's an effort to keep the eggs from predators and improve the chances of survival for the hatchlings.

Based on these observations, experts suspect that other deep-sea-dwelling squids may also brood their eggs. Octopuses have been more commonly observed showing the behavior.

The first squid observed to brood their eggs was a Gonatus onyx or clawed arm hook squid. The species was spotted in 2002 in Monterey Bay using Tiburon, MBARI's ROV. The footage revealed that the squid utilizes the hooks on its arms to carry a cluster of eggs up to 3,000 at a time. Scientists published the details of the egg cradling behavior of the G. onyx in the journal Nature in 2005.

Documenting videos like that of a squid laying its eggs shows the importance of exploring the deep crevices of the waters and learning about elusive species. MBAEI researchers explain that the deep ocean is challenging to study, often providing brief glimpses into the unique behavior of deep-sea animals. Each observation logged by their ROVs delivers another piece of the puzzle, helping experts improve our understanding of life in the deep, reports Smithsonian Magazine.