More Than Skin-Deep

While many humans are unfortunately dazzled by fame, celebrity, glitz and glamour, some fish have learned that when it comes to choosing a mate, it’s not outward appearances that matter, but what lies beneath the surface.

Thanks to a special camera and pioneering work by marine biologists at the University of Texas, scientists have now been able to show that female swordtails have evolved to choose their mates based on colourful displays that are invisible to humans.

Based on polarised light, the attention-grabbing patterns are used by males in much the same way as peacocks use their amazing plumage to attract peahens, but they are only visible in polarized light. The more polarization a male has, the greater his chances of successfully finding a mate.

While there are various animals such as octopi that can detect these types of wavelengths, this is the first study to prove that this ability is present in vertebrates, meaning that scientists now have an even greater understanding of these fascinating fish, and conclusive proof that there’s more to love than meets the eye…