The most dangerous spider in the world can modify its venom

Far from the comics, a venomous spider bite can be very painful and even fatal. But when it comes to the Australian spider, everything gets worse if you make him angry.

This spider is known for its powerful venom and distinctive funnel web. They are native to Australia and their natural habitat includes both moist woodland and suburban areas.

Its venom is highly toxic and can be fatal. Symptoms of a funnel-shaped spider bite can include severe pain, sweating, nausea, and vomiting, and in severe cases, can lead to breathing or heart problems.

However, with the availability of antivenoms and prompt medical attention, deaths from spider bites are extremely rare: only 13 deaths (7 in children) were recorded in Australia in the 20th century.

Now, a new study into how funnel-web spiders produce their venom reveals that factors such as the spider’s heart rate and defensive posture can affect the amount of chemicals released through its barbed fangs.

Spiders to the fullest

The researchers collected samples from four species of Australian funnel-web spiders: border bands (Hadronyche valida), Darling Downs (Hadronyche infensa), southern tree-dwelling (Hadronyche cerberea) and Sydney (Atrax robustus).

All of them, then, have been subjected to uncomfortable tests. The first was about predation, which scientists simulate by blowing gusts of gusts at spiders or poking them with tweezers. The second context involved interacting with another spider of the same species. The third scenario was exploring an unknown area.

During these tests, the researchers recorded the spiders’ behavior and measured their heart rates using a laser screen to determine their metabolic rate index. Its venom was then collected and analyzed by mass spectrometry.

In three of the species, there did not appear to be a relationship between their behavior, heart rate, and the composition of their venom. However, the scientists noticed an exception in one spider: the higher heart rate and defensiveness of border rangers appeared to be related to altered venom composition.

What is the use of spider venom?

Because funnel-shaped spider venoms are composed of complex combinations with a wide range of possible uses, such as organic pesticides and medicines, understanding why these spiders produce these mixtures can facilitate and improve the extraction and use of the venoms. This can also help us better understand the function of venom. (Text and photo: courtesy of National Geographic)