Do spiders dream?
Sayahna R V
Do you really think spiders sleep and dream??
When we are observing the behavior of a spider in its web ,they some times jumps or twitches their legs like a gost.To get an answer to this question,Daniela Rößler, an ecologist the University of Konstanz closely observed the behaviour of spider during the coronavirus lockdowns.Rößler became fascinated by the tiny jumping spiders from their web. After nightfall, some jumping spiders,retired to little silken pouches called “retreats” which is of small size.
Jumping spiders may have REM(rapid eye movement )like twitches when they sleep, suggesting that dreams may be much more widespread in the animal kingdom than previously realized.
Researchers found that the jumping spiders, known for their acrobatic hunting, exhibited signs of R.E.M. sleep. But it is not known whether they dream, or sleep.
As the spiders twitch their legs and move their eyes, Evarcha arcuata, a species of jumping spiders, which show something reminiscent of rapid eye movement, or R.E.M.
R.E.M. is the phase of sleep during which most human dreaming occurs.so there is a possibility of dreaming.
The study reviels that R.E.M. sleep may be more common than realized in animals, which may help us to untangle the mysteries of its purpose and evolution.
Daniela Rößler, a behavioral ecologist,was enchanted when she noticed that jumping spiders sometimes dangle upside down from their webs during the night time . She started filming the resting arachnids and noticed other odd behaviors. ” All of a sudden, they would make these crazy movements with the legs and start twitching like in a ghost movie. That jerky and weird movements in limbs are a true evidence of of R.E.M. sleep, a state in which most of the body’s muscles go slacking and the brain’s electrical activity acts as being awaken . And there’s the darting eyes, from which R.E.M. gets its name. But it’s difficult to spot it in animals with eyes that do not move, including spiders.However, part of a jumping spider’s eye does move.
The acrobatic arachnids (a species of spider) have eight eyes in total. Behind the lenses of their two biggest eyes are light-catching retinas which move to scan the environment.
So Dr. Rößler’s team searched for flitting retinas during rest time in spiderlings which are younger than 10 days old. Paul Shaw, a neuroscientist at the Washington University School of Medicine, observed and commented that it’s really clever.
During the night time the researchers filmed the arachnids(a species of the spider) using an infrared camera. For all 34 sleeping spiderlings, they saw lots of coinciding retinal and limb movements, which typically lasting around 80 seconds and occurred every 15 to 20 minutes. The researchers closely observed behaviours in the shifting of silk-producing spinnerets to a scrunching of all legs which resembled a dead spider. But watching hours of resting spiders didn’t dull Dr Rößler to sleep. Each spider’s movements looked unique, she said. “I was always looking forward to the next R.E.M.”
But it is sure that the spiders are experiencing something akin to REM sleep in humans. The researchers first need to confirm the spiders are actually asleep during this phase by showing that they are less responsive to their environment.
Studying REM sleep behaviour across a wide range of species, including these spiders, could help us understand how it works and why it exists. Some researchers have theorized that REM sleep’s characteristic eye movements in humans reflect visual scenes that are playing out while we are dreaming. This raises the exciting possibility that other animals that have a REM-like state also experience dreams.
Read more : Friction
Check your knowledge
The new study suggests they do .Studying REM sleep behaviour accross wide range of species, including these spiders, could help us understand how it works and why it exists.
Most spiders live about two years, but some have been known to live up to 20 years when in captivity. Female spiders tend to live longer than male spiders. Many male spiders reach maturity within two years and die after mating.
Spiders may tuck-in their legs when they are chilly, but they do not really, “Curl-up,” in the traditional sense.
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