The study, reported in the February issue of the American Naturalist, found that the more male fish present during spawning, the more likely a male will try to eat the eggs, since it's less likely he fertilized them.
"The most drastic decision a father can make is to cannibalize his own offspring," wrote Suzanne Gray and Lawrence Dill of Simon Fraser University and Jeffrey McKinnon of University of Wisconsin, Whitewater. "These results support and extend previous findings suggesting that confidence of paternity is a key factor in determining a male's behavior toward his offspring, including whether or not to eat them."
The researchers studied Telmatherina sarasinorum, a small fish found in Lake Matano in Indonesia, and found that females who can be sure of their relationship to their eggs never cannibalized.
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