The swordtail is a beginner-friendly tropical fish species. This hardy fish comes in various vibrant colors and can be kept in a freshwater tank as small as 10 gallons. These traits make swordtails ...

When it comes to mating, dominant green swordtail fish let their tails do the talking. Female green swordtail fish mature faster sexually when they see males with larger-than-usual tails, according to ...

Females often have traits that may be useful as indicators of their reproductive status. Female Green Swordtails (Xiphophorus helleri) have a brood patch, a darkened region on their abdomen that is ...

LONDON (Reuters) - Size matters in the science of sexual attraction -- especially if you are a fish. Scientists at the Universities of Exeter and Glasgow have found that female green swordtail fish ...