Jumping spiders show REM-like sleep, study finds
Jumping spiders of the species Portia fimbriata cycle through quiet sleep and a REM-like stage with twitches and eye moves, according to ABC Australia. Sleeping spiders woke more slowly to loud noise. The lag was strongest in the REM-like phase, researchers said.
Portia fimbriata jumping spiders move through distinct sleep stages that include a REM-like phase, according to ABC Australia's report on a PNAS study. Researchers filmed the spiders shifting from a still, quiet stage into a REM-like stage with leg curls, eye movements, and arm twitching.
Co-author Nadja Geiger said a hallmark of sleep is slower or missing responses to outside cues. The team woke spiders with a loud noise during quiet rest, during the REM-like stage, and while they were clearly awake. Response times stretched in both sleep-like stages and were slowest in the REM-like phase, with some spiders not reacting at all.
Outside expert Thomas White of the University of Sydney said in the ABC Australia piece the paper is the strongest behavioral case yet for sleep in any arachnid. He noted spiders diverged from vertebrates hundreds of millions of years ago, but said similar twitchy rest in dogs and other animals makes the comparison less far-fetched. Co-author Daniela Rößler said structured sleep with REM-like phases in such different brains may mean the basic architecture of sleep is older and more widespread than once thought.
The fringed jumping spider can grow up to about 10 millimeters long. The team now wants to study spider sleep in the wild in northern Queensland and Western Australia, including how artificial light and habitat change affect rest. Only ABC Australia is counted for this card.
What we know: ABC Australia reports a PNAS study finding quiet and REM-like sleep stages in Portia fimbriata, with slower wake-ups in those stages.
What we don't: Only ABC Australia has reported this so far. NewsHabit hasn't seen independent confirmation.
Where outlets agree This card follows ABC Australia's account of the PNAS jumping-spider sleep study. Other outlets were not counted as independent confirmation.
Where they differ ABC Australia presents the study's REM-like sleep findings. Outside expert Thomas White supports the behavioral case for spider sleep.