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.

Some fish lay eggs, others give birth directly to tiny wiggly babies. According to a new Nature Communications study, giving birth to live young increased the diversity of ray-finned fishes like ...

A new study has shown that some fish have more complex personalities than was previously thought. Scientists at the University of Exeter studying the behavior of Trinidadian guppies discovered that ...

A properly dressed male guppy, with its gaudy blue spots and brilliant splashes of orange, can't help but stand out. But for a fish that spends its life swimming among predators, it seems that good ...

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 ...