Eat the Kids: Are cannibal fish just freshening the O2?

Why would the babysitter eat some of the babies? In beaugregory damselfish, the answer may be that by snacking on some embryos, males tending their offspring make more oxygen available for the rest, according to a new study of cannibalism.

Giving males some extra food in the wild didn’t change their cannibalistic tendencies, says Adam Payne of the University of London.