What looks like a spider but isn’t one, lives underwater and breathes through its legs? That would be the mysterious sea spider. With over 1,300 species living in every ocean, these marine arthropods ...

The knotty sea spider, Pycnogonum litorale, is not actually a spider, but it does represent a significant early branch in the genetic family tree that includes spiders, as well as scorpions, ticks and ...