Nursery Web Spider from South Africa

Subject:  What spider is this carrying it’s egg sac?
Geographic location of the bug:  Robertson, Western Cape, South Africa
Date: 08/13/2018
Time: 12:19 PM EDT
Your letter to the bugman:  Hi there,
We were wondering if you could tell us what kind of spider this is carrying it’s egg sac?
How you want your letter signed:  Pearce

Nursery Web Spider with Egg Sac

Dear Pearce,
We can narrow this identification down to the family, but we cannot say for certain that we know the genus or species.  There are two families of Spiders where the female carries about the egg sac.  Wolf Spiders in the family Lycosidae drag the egg sac from the spinnerets while Nursery Web Spiders, including Fishing Spiders, in the family Pisauridae carry the egg sac in the chelicerae or fangs.  Your individual is a Nursery Web Spider.  According to BioDiversity Explorer:  “All pisaurids construct a round white egg case that is carried under the sternum held in the chelicerae (jaws). This causes them to assume a tiptoe stance. Just before the eggs are due to hatch, the female constructs a nursery web around the egg case. This is attached to the vegetation with a supporting web around it. The spiderlings leave the nursery after one or two moults.”  Wikimedia Commons has an image that looks very much like your individual, and it is identified as
Chiasmopes lineatus, but there are no images of that genus on BioDiversity Explorer.  The only other representative of the genus we could find is on Project Noah, but it is a much thinner and smaller male.

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