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Researchers find aggression pheromone
A University of the Sunshine Coast researcher has helped discover the reproductive chemical that makes male squid fight – and it’s a protein similar to that found in humans.
Dr Scott Cummins, of the USC Genecology Research Group, worked with a research team on the east coast of North America until he returned to Australia in 2007.
The team, led by Roger Hanlon of the Marine Biological Laboratory at Woods Hole, Massachusetts, studied the Longfin squid.
These squid mate and lay their eggs annually in shallow warm waters between North Carolina and southern Maine.
Dr Cummins, a chemical biologist, has since finalised his analyses for the project at USC’s laboratories, where he is also the University’s Senior Lecturer in Physiology.
The final collaborative report is featured in the February edition of respected international journal Current Biology.
Dr Cummins said the team had identified a single protein pheromone that was produced in the female reproductive tract and embedded on the surface of their eggs laid on the sea floor.
“When male squid came into contact with this pheromone on the outside of the eggs, they instantly went from swimming along calmly and minding their own business to a state of extreme aggression where they fought for potential mates,” he said.
“That's notable because aggression is generally thought to be a complex process involving neural, hormonal, physiological and psychological stimuli.”
It is believed to be the first detailed evidence of an aggression-inducing contact pheromone in an aquatic animal.
Dr Cummins said squid were highly advanced marine invertebrates with a complex mating system rivalling that of vertebrates.
He said the identified pheromone belonged to a family of proteins also found in the reproductive glands of vertebrates including humans.
“They are found at high levels in human and mouse seminal fluid,” he said.
"The functions of (these proteins) in vertebrates have not been determined, but our findings in squids may inspire other researchers to consider similar functions in higher vertebrates.”
The USC GeneCology Research Group studies individual species’ biology, ecology, ecological communities and habitats.
— Julie Gatehouse