All animals have a circadian clock that controls the rhythm of various animal behaviors and physiological functions, such as when to sleep, when to wake up, when to prey, and when to secrete hormones. The biological clock of different animals is fast or slow, and its cycle is mostly close to 24 hours to adapt to the normal day and night.
However, there are always exceptions, and some animals live a different rhythm. Biologists at the University of Tennessee placed three species of orbweb spiders in complete darkness and used infrared light to detect their activity patterns. It was found that the periods of the built-in biological clocks of the three orbweb spiders are far less than 24 hours, only 17.4, 18.5 and 19 hours respectively – this is also the shortest known biological clock in animals.
When kept in a dark place, these orb-web spiders were always active in cycles of less than 20 hours, but they were also very capable of adjusting for jet lag when exposed to light. That is, when exposed to the wild, the round-web spider “resets” its biological clock every day. It wove its web early before sunrise and stays still during the day. When night falls, the round-web spider becomes active again and looks for prey. And weave the web – complete a period of only 18 hours. But after 18 hours, instead of starting a new round of activity, the round-web spiders moved on to the previous day’s schedule again by dawn the next day without any discomfort.
Biologists once believed that having a biological clock that deviates too far from 24 hours is a very bad thing for the survival of animals. For example, most animals, including humans, will experience physiological symptoms within a week if they are frequently jet-lagged. Disturbance of rhythm. However, the three orb-web spiders have made biologists realize that there are always some mavericks in the biological world. Perhaps, this short rhythm period helps the orbweb spiders better avoid predators. These spiders can leisurely weave their webs before dawn and after the sun sets, avoiding the industrious birds that wake up early and come home late — which may be beneficial to the survival of the round-web spiders.
In order to gain more information, biologists are also looking at other spider species, and they have found that in addition to the short-period orb-web spiders, some spiders have extraordinarily long rhythms, about 27 to 29 hours, and some even seem to have no circadian rhythm at all, which is equally astonishing.
Since night shifters and people who frequently travel across time zones experience jet lag, which is a daily comfort for these strange spiders, biologists believe that the difference in spiders The normal biological clock is a very worthy topic of study. If the secrets of how spiders regulate their biological clocks can be uncovered, they may be used to benefit humans.
