Broody squid carry their eggs in their arms


Blue Ring
Oct 28, 2004
This is from an article in the recent edition of New Scientist:

A broody species of squid has been found to carry hundreds of its eggs under its many arms. It is the first species of squid known to look after its clutch.

Usually squids simply drop their eggs on the sea floor and leave them to survive on their own, although some species of octopus are known to guard their clutch. But scientists captured on film the parental care lavished by Gonatus onyx on its eggs.

Gonatus madokai also broods eggs

Passed to us from John Bower - Hokkaido University

A new study led by a group of Japanese scientists has identified a squid in northern Japan that broods its eggs

Parental care of eggs or young is uncommon in invertebrates. This is true for most squids, but a new study published in The Biological Bulletin (; pages 259-262) shows that females of a species in northern Japan care for their spawned eggs by brooding them in their arms. Divers in northern Japan have observed this behavior annually in nearshore waters off the Shiretoko Peninsula since 1991, but the species has until now remained unidentified.

The cover photo (, taken off Rausu, Hokkaido, in May 2006 shows a female brooding a single-layer, sheet-like egg mass attached to its arm hooks. The small, oval eggs are visible within the dark, viscous material that formed the egg mass. The authors describe the brooding behavior and identify the species as Gonatus madokai (family Gonatidae), now the third squid species known to brood. They suggest that females might continue this behavior for several months, during which time they weaken, undergo gelatinous degeneration, and are presumably unable to feed.

Why the females would devote so much time and energy to caring for the eggs remains a mystery, but brooding could increase offspring fitness by protecting the developing embryos from egg predators and hypoxia. Even less is known about the evolutionary origin of this behavior, but the authors suggest that more brooding squids await discovery in the deep sea, which could provide more clues to understanding this intriguing behavior.
From Kat's Western Flyer Expedition

OK, it's official. I'm stowing away on this ship and never leaving. This morning we saw a brooding Gonatus at 1600m, waving her inky egg sheet gently as she floated along. We got a very good look at her and were even able to zoom in on the eggs--we could see eye spots! These images are screen grabs from my little video camera, which was filming the live feed on screen, so they're not great quality, but you'll get the idea!

See full expedition posts and photos here


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