• marzhall@lemmy.world
    link
    fedilink
    English
    arrow-up
    6
    ·
    edit-2
    1 day ago

    Invertebrates? No. All out

    I invite you to meet the awesome jumping spider, whose eyes are very especially needed set up to be forward-facing for depth perception for their jumps, and who hunt other spiders, as well as the wolf spider, who are also a hunting (as opposed to web) spider.

    In fact, you can use the chart of spider eye layouts to pretty much identify whether you’re looking at a spider who builds webs and waits or a spider who hunts:

     a drawing of different spider faces to their names

    Anyone with two big forward-facing eyes is probably looking around for their next meal; the rest are building a web, trapdoor, or taking some other approach.

    • KingGimpicus@sh.itjust.works
      link
      fedilink
      English
      arrow-up
      2
      ·
      19 hours ago

      Had a bunch of wolf spiders in the last shop i worked at as a welder. They have eye shine like cats and alligators. It was always easy to tell the wolf spiders from black widows even behind a dusty welding machine because you can see the little wolf spider eyes looking back at you.

    • monotremata@lemmy.ca
      link
      fedilink
      English
      arrow-up
      3
      ·
      1 day ago

      Also crabs. I mean, their eyes are often on stalks and more mobile than mammalian eyes, and they’re compound, so they have a very wide field of view, but they’re still often basically in front, and they do apparently provide depth cues for hunting thanks to this.

      https://www.jneurosci.org/content/38/31/6933

      It also occurred to me to look up about dragonflies, and it seems they mostly hunt dorsally (which is a pretty viable option if you’re flying). BUT I found this article about Damselflies, which notes that they rely on binocular overlap and line up their prey in front of them. Which is pretty cool.

      https://www.sciencedirect.com/science/article/pii/S0960982219316641

      • ChickenLadyLovesLife@lemmy.world
        link
        fedilink
        English
        arrow-up
        3
        ·
        19 hours ago

        Horseshoe crabs have nine different types of eyes. Even that tail is essentially a kind of eye, covered with photoreceptors. Not sure of the relevance of this horseshoe crab fact, it’s just fucking interesting.