It does not have eyes or photoreceptors (specialized light-sensitive neurons) but it is capable of detecting sunlight rays. And to others it is poisonous and capable of paralyzing in a few seconds prey that is several times its size and weight.
It is the Chinese red-headed centipede and, as its scientific name, Scolopendra subspinipes mutilans, indicates, it is specifically a scolopendra, that is, a relatively large chilopod myriapod (up to 30 centimeters in diameter). long) endowed with strong jaws and forcipules with which it injects venom into its prey. Bites from various species of these large centipedes can be very painful to humans, but rarely fatal.
The subspecies S. subspinipes mutilans is common in large areas of Asia and Oceania and one of its main characteristics, in addition to its predatory voracity, is that it does not have eyes and, consequently, the specialized photoreceptors and neurons for light perception that They are located in the outer retina of many species.
Despite not having the sense of sight, S. subspinipes mutilans is capable of reacting to the presence of sunlight, an apparent paradox that now seems to have been explained thanks to a study led by experts from the Northeast Forestry University (China). ), in collaboration with researchers from the Zhejiang University School of Medicine (China).
The results published by this team in an article in the Proceedings of the National Academy of Sciences (PNAS) detail the tests carried out in the laboratory with several of these centipedes to verify how and why they hid from sunlight despite not have eyes.
Previous research has shown that centipedes actively avoid sunlight, although whether this is to avoid predators or to avoid overheating is not known. Other previous work has also shown that several species of insects that do not have eyes or photoreceptors are capable of reacting to sunlight.
To test the response of S. subspinipes mutilans specifically, the researchers conducted experiments that involved placing specimens in transparent containers, some of which were covered with black adhesive tape. They then studied how the centipedes moved when exposed to different amounts of light. They also used thermal cameras to record changes in body temperature during exposure to sunlight.
In the main part of their study, the authors found that the temperature of the antennae rose rapidly when exposed to sunlight.
To confirm that the antennae alerted the centipedes to sunlight, the researchers covered the curly red segmented structures on the antennae of several specimens and then retested the reaction of these scolopendras to see how they responded to sudden bursts of light. . Thus, they were able to verify that centipedes with covered antennae had much less reaction to the presence of light.
In the second part of the study, the Chinese researchers analyzed the antennae in detail and discovered the existence of thermal receptors called BRTNaC1, which served as ion channels sensitive to sunlight, causing an increase in temperature that facilitates the reaction of the scolopendra.
