Swordfish heat their eyes for the hunt
Swordfish heat up their eyes to improve their tracking of fast-moving prey in deep, cold water, suggests a new study. Researchers already knew that certain large ocean predators - such as swordfish, tuna and some sharks - keep at least their eyes and brains warmer than the ambient ocean temperature. But this is the first convincing biological explanation for why, says the team led by Kerstin Fritsches at the University of Queensland, Australia.