Some male fish let rivals woo females and then hijack their courtship

By Christa Lesté-Lasserre

The dominant males in one species of Amazonian fish have developed a simple way to grab mating opportunities. They hide while smaller, less-dominant males work hard to persuade a female to lay eggs, then they come forward and steal the receptive female’s attention.

Lower-ranking male sailfin tetras (Crenuchus spilurus) put in a lot of time and effort to court females. They may spend several days circling aquatic weeds with their colourful fins fully extended.

Tiago da Silva Pires at the National Institute for …