Spider Guarding its Egg Sac

Description:

Araneidae; Cyrtophora unicolor (Doleschall, 1857). When I posted this spotting on Jan 22, 2023 I called it "Unidentified Araneae" because I just could not make any progress in identifying it. As soon as I received the species suggestion from kurtc, I realised that I had previously encountered a similar spider. Back in 2016 (long before I eventually got a reliable internet server which enabled me to join Project Noah), I spotted a Cyrtophora exanthematica which I posted on PN in 2022 - https://www.projectnoah.org/spottings/18... I really don't know why I did not make a connection with my C. exanthematica and this C. unicolor, but I suspect that it was because the posture of the latter, "spread-eagled" on its egg sac makes it look so different from the pictures I have of exanthematica which are are all either sitting on a leaf or hanging on its web.

Habitat:

This spider, on its web sac, was spotted on a Banana Plant (Musa sapientum) in our backyard. As everyone knows, the leaves of banana plants grow straight up from the stem (pseudostem) and then bend over, under their own weight and form an arch shape. This spider had attached its egg sac to the underside of a leaf, up at the top of the arch. As you can (just about) see in my last photo, there is a kind of silk rope made up of several silk strands. The lower end is secured directly to the top of the the egg sack, but at the upper end, the "rope" appears to be splayed out to provide a number of mooring points attached to the leaf. What I was unable to show in my photos was that the "rope" at the bottom of the egg sac was also splayed out, but with much longer mooring lines, running all the way out to the edges of the "arched over" leaf. Finally, yes you've guessed it, the little clumps of material on the ropes, near the top and the bottom of the sac appear to be spider excrement. I think it is probably placed there to discourage ants which might want to steal eggs from the sac.