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.

Duping a guppy is easier than duping a ring dove — at least when it comes to a classic optical illusion.

To the surprise of the scientists, populations of a South American guppy were spotted at the Fernando de Noronha archipelago, a volcanic island in the South Atlantic. Even if being easily adaptable ...

They may look innocent, but a new study suggests that guppies may have a darker side. Researchers from the University of Exeter have discovered that Trinidadian guppies change their eyes from silver ...