Guppies can be fooled by optical illusions into believing objects are smaller or larger than they really are. This suggests they might not always make the best choices in their natural environment.

Scientists have discovered that female guppies choose males with uncommon color patterns to drive the evolution of their ...

Tiny guppy fish change their eye colour to warn off rivals, new research shows. When facing an opponent, Trinidadian guppies rapidly turn their irises from silver to black before attacking their ...

See more of our trusted coverage when you search. Prefer Newsweek on Google to see more of our trusted coverage when you search. How people respond to stressful situations can say a lot about their ...

Male guppies pay a high cost for their sexual harassment of female guppies – including much higher mortality rates – a new study from Macquarie University has found. Sexual harassment in guppies, or ...

When Robert Heathcote dips his head into the rivers of Trinidad, he’ll often see little black dots moving through the water, even when it’s murky. Those dots are the eyes of small, inch-long fish ...

Bringing a fish home for your child might sound like a small decision, but it’s actually a big step into responsibility, bonding, and joy. Among the most popular pet fish, goldfish and guppies top the ...

Trinidadian guppies, ubiquitous in freshwater aquariums around the world, are no bigger than your thumb. But for Sarah Fitzpatrick, assistant professor in Michigan State University's Department of ...

The streams of Trinidad and Tobago are home to the most unexpected of landscape gardeners. They're guppies - tiny and beautifully coloured fish, just an inch or so long. Without tools or plans, they ...

Tiny guppy fish change their eye colour to warn off rivals, new research shows. When facing an opponent, Trinidadian guppies rapidly turn their irises from silver to black before attacking their ...