Sexual harassment in the wild by some fish may be causing the female of the species to risk death by swimming with predators, according to research.
The research was carried out in the Rain Forest of Trinidad
Dr Darren Croft from the University of Wales, Bangor along with a team from Leeds University found female guppies often avoided the males.
The study, published in The American Naturalist, is used to understand behaviour in order to conserve and protect species and habitats.
The guppy is a popular aquarium fish.
"Male guppies spend most of their time displaying to females, but if his courtship displays don't impress her, males will attempt to sneak a mating with her when she is not looking," said Dr Croft, whose team carried out its research in Trinidad.
"As in many vertebrates it is the males that 'dress to impress', males guppies have bright colour patterns they use to attract females, whilst females are a dull brown colour," he added.
Because the bright colours also attract predators male fish prefer to swim in 'safer' water.
Females guppies might be using this to their advantage by venturing into the deep water where the predators lurk, and where it was too dangerous for the males to follow.
By doing so, females avoid the attention of males but risk being eaten by the predators.
Dr Croft said sexual segregation was not restricted to fish.
"It is often found in deer and antelopes and may even occur in humans.
"Ancient Greek mythology tells of a nation of female warriors knows as the Amazons who lived on an island an only met men to trade and reproduce," he said.
Understanding why and how this behaviour occurs is essential to conserve and protect species and habitats, said Dr Croft.
"In many ecosystems predators are the first to go extinct and our work shows that this may have any, perhaps unexpected, knock on effects - in this case females may suffer more sexual harassment," he added.