TOWNSVILLE, Australia, June 27 (UPI) -- Australian scientists have discovered fish use the threat of punishment to maintain stability in their social order.
Australian Research Council scientists at James Cook University said their discovery has implications for the entire animal kingdom, including humans.
Studying small goby fish at Lizard Island on Australia's Great Barrier Reef, Marian Wong and colleagues showed the threat of expulsion from the group acts as a powerful deterrent to keep subordinate fish from challenging those more dominant than they.
In fact, the researchers discovered subordinate fish deliberately diet to remain smaller than their superiors -- and so present no threat that might lead to their being cast out and subsequently perishing.
In the case of the gobies, the researchers found only the top male and top female mate, and all the other females have to wait their turn in a queue based on their size. Wong found each fish has a size difference of about 5 percent from the one above and the one below it in the queue.
The study is detailed in the Proceedings of the Royal Society of London Series B.