Stanford researchers have gained new insights into how the rise of reproductive barriers between organisms creates new species and drives the incredible diversification of life on Earth. One major way ...

When you've got to go, you've got to go -- upstream, that is, if you are a male swordtail fish seeking a mate, according to research from Texas A&M University. A recent study led by Texas A&M ...

A polluted river in Mexico may be scrambling the love lives of two small fish species — so much so that it may be erasing the ...

Are you thinking of keeping fish as pets but don’t know where to start? Take a look at two of the most popular choices for beginners - Guppy fish and Swordtail fish. Here are the reasons why these ...

Colourful aquarium fish known as swordtails, size up competitors' tailfins before fighting, US scientists show. Often a male just has to show his big elongated tail, which looks like a pointy sword, ...

When it comes to reproduction, most fish are external fertilizers, crop dusting eggs in a cloud of sperm. But swordtails (Xiphophorus) aren’t like most fish. These fish fertilize eggs internally and ...

When you've got to go, you've got to go -- upstream, that is, if you are a male swordtail fish seeking a mate, according to new research. When you've got to go, you've got to go -- upstream, that is, ...