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X-ray image of an adult female Bahamas mosquitofish where a fish she had eaten can be seen inside of her, revealing an occurrence of cannibalism. Credit: Brian Langerhans |
Mosquitofish and guppies, though known to be cannibalistic in captivity, are extremely unlikely to be cannibals in wild settings, and the rare instances of cannibalism in these fish are likely due to strong competition for food. The findings, from a new study led by U.S. and U.K. researchers, could have implications not only for fish enthusiasts and scientists who use mosquitofish as models for ecological and evolutionary studies, but could also help explain the causes and frequency of cannibalism in other animals.
Cannibalism, preying on and eating other individuals of your own species, is a peculiar behavior, featuring prominently in human mythology and fiction. But how common is it in nature, and why would organisms' resort to such an extreme course of action just to get a meal?
Brian Langerhans, associate professor of biology at North Carolina State University, and Rüdiger Riesch, senior lecturer in evolutionary biology at Royal Holloway University of London, decided to find out by looking at over a decade’s worth of data gained from almost 12,000 fish across 17 species in the wild.