Don’t Mess with Squid Eggs!

Squid eggs photographed at Plum Cove on Massachusetts’ Cape Ann.

SOMETIMES, DURING DIVES, YOU ENCOUNTER THESE THINGS attached to the bottom. They’re squid eggs. Here’s a hint: Don’t Mess With Them!

Remember Kirk Douglas battling the giant squid in 20,000 Leagues Under the Sea? It’s could be like that. Maybe.


When a female squid deposits her eggs on the seafloor, she also imbues them with a protein that essentially drives male squids crazy – not about her but about the eggs.

Studying longfin squids (Loligo pealeii), researchers discovered that the outer tunics of squid eggs are embedded with a protein called Loligo microseminoprotein.

Squid egg clusters, consisting of two-inch-long, finger-shaped gelatinous capsules, are deposited on the seafloor, attached to algae or other features. They’re communal, meaning that more than one squid will contribute eggs.  Each capsule holds up to 200 eggs. They’re attractive as food for fish and other predators.


Male squids are drawn to the eggs visually, but touching them – and the protein – has the effect of transforming them into lean, mean fighting machines, ready to take on any other male squids who might get near the eggs. [Editor’s note: I’ve been told anecdotally that squids can become aggressive towards divers who touch the eggs.]

Similar proteins are found in other animals, including mammals, although their function is not clear. This is the first substance found in marine creatures shown to trigger aggression.

PRINCIPAL SOURCES: Current Biology, 10 February 2011, Scott F. Cummins, et al; Marine Life of the North Atlantic, Andrew Martinez.