OK so “Misconception Tuesday” doesn’t quite have the same ring to it as “Misconception Monday”, but it will have to do for this week.
So what is the misconception of the day? That all “Daddy Long Legs” are spiders.
Well, for some of the organisms that humans call “Daddy Long Legs”, this is, in fact, true. These spiders, also commonly known as Cellar Spiders, like to build their webs in cool, damp, dark spaces, or even in houses, where you have probably seen them lurking in the corners above your bed (errr, maybe that’s just me). However, there is another group of organisms that people call “Daddy Long Legs”, which are actually not spiders (Araneae) at all. They are part of a different arachnid order called Opiliones (commonly, Harvestmen).
So, how can you tell the difference between a DLL-spider and a DLL-harvestmen? It’s simple: Harvestmen do not have silk glands, and cannot spin webs. Therefore, if you see a long-legged individual in a web, it is likely a spider. What if the individual is not in a web? Well, it is still fairly easy to tell the two apart based on the shapes of their bodies:
As you can see, the Harvestman on the left has a much rounder body, with less apparent segmentation. On the other hand,we can clearly see the segmentation in the spider between the cephalothorax and the abdomen. And of course, we can see why both are called Daddy Long Legs 🙂