Male fish turn to cannibalism when uncertain of paternity

Jan 19, 2007
Egg Cannibalism
Mating, sneaking and egg cannibalism in T. sarasinorum. Credit: Photograph by S. Gray

A study from the February issue of the American Naturalist is the first to demonstrate that male fish are more likely to eat their offspring when they have been cuckolded during the act of spawning. Moreover, the more males that are present during spawning, the more likely it is that a male will try to eat the eggs when they are laid, as it is less likely that he fertilized them.

"The most drastic decision a father can make is to cannibalize his own offspring," writes Suzanne Gray (Ph.D. candidate at Simon Fraser University), Lawrence Dill (Simon Fraser University), and Jeffrey McKinnon (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."

Predicted by theory, this pattern had never previously before been demonstrated. Studying Telmatherina sarasinorum, a small, colorful fish found in Lake Matano in Indonesia, the researchers found that females, who can be sure of their relationship to their eggs, never cannibalized. However, an increased level of cuckoldry led to an increased rate of cannibalism among males.

"We want to understand how behaviors evolve," says Gray, "and how behaviors, such as cannibalism, contribute to the diversity we see within and between different species."

Source: University of Chicago

Explore further: The origins of polarized nervous systems

add to favorites email to friend print save as pdf

Related Stories

Every time a fig is born there is a wasp massacre

Jan 28, 2015

"Don't put all your eggs in one basket" is a common refrain. But usually it is not followed by the words "because your neighbours may kill you". However, this is precisely the scenario faced by some female ...

Pumas in populated areas kill more and eat less

Jan 22, 2015

Female pumas in areas with a high density of housing kill more deer but eat less of the carcasses than those in areas with little housing, finds a study in Proceedings of the Royal Society B.

Behavioral ecologist studies beetle charisma

Jan 19, 2015

What attracts partners to each other? Is it a flashy car? A bright, colorful outfit? And how do these preferences ultimately affect the evolution and diversity of a species over time?

Braving the cold to understand what makes squirrels tick

Jan 06, 2015

For most of us, our day begins with an alarm of some sort. We work, eat, and play, all on some sort of a schedule. While our world is dictated by mechanical clocks, the schedule of the non-human animal kingdom ...

Recommended for you

The origins of polarized nervous systems

54 minutes ago

(Phys.org)—There is no mistaking the first action potential you ever fired. It was the one that blocked all the other sperm from stealing your egg. After that, your spikes only got more interesting. Waves ...

Study shows one reason why pigeons so rarely crash

3 hours ago

(Phys.org)—A pair of researchers with Harvard University has uncovered one of the secrets behind pigeons' impressive flight abilities. In their paper published in Proceedings of the National Academy of ...

Gold standard management of the diabetic cat

4 hours ago

The International Society of Feline Medicine (ISFM), the veterinary division of International Cat Care, has convened an expert panel of veterinary clinicians and academics to produce practical guidance to ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.