With Zavier Evans
The world is a beautiful and bizarrely complex place. We in Australia are fortunate in being a biodiversity hotspot for a large number of highly specialised creatures found nowhere else on the globe - including the ones that can sometimes give us bad dreams.
A common sight when walking around the well lit grasslands in Wilson's Prom is a big chaotic net of austracanthus spiders, also known as jewel or christmas spiders. These harmless natives form large social colonies on a single three dimensional, deliberately visible web. They aren't aggressive, and will invariably flee when disturbed, clambering about awkwardly on their short, stubby legs.
Arachnophobes would probably argue that their spiky bodies and aggro colours are the stuff of nightmares. But while we might dream of spiders, have you ever wondered if they themselves dream?
In 2020, a German arachnologist named Daniela Robler had a takeaway container of jumping spiders sitting on her windowsill, hoping to test their reactions to 3D printed predatory spiders.
One day, she noticed the spiders were hanging from the lid on a thread of silk, utterly motionless. She was baffled, but the real surprise came when, as niche scientists are wont to do, she spied on them all night. Their legs began to twitch periodically, and realising the potential discovery she had stumbled upon, she immediately changed her research plans to discover whether they were undergoing REM sleep, the kind of sleep in which we dream.
Researching rapid eye movement sleep is usually confined to vertebrates, as most terrestrial arthropods (spiders, insects) don't have movable eyes, however jumping spiders have movable retinal tubes, which can only be seen through the transparent bodies of juveniles.
Upon recording 34 sleeping spiderlings, Robler and her team have found strong evidence of an REM-like phase in the habits of these spiders. The observed eye movement patterns during REM sleep have been hypothesised to be directly linked to the visual scene experienced while dreaming. This is not conclusive evidence that spiders dream, but it is a compelling thought, and it begs the question: if they do dream, what do they dream about? A blank void? Toothsome flies? The overwhelming love of holding one's newborn spider?
If you want to see some very closeup videos of baby spiders wiggling their eyes and wriggling in their sleep, you can visit the original study at https://shorturl.at/omeAD. And keep your eyes peeled for their spiky little austracanthus cousins next time you take a walk through the bush.
