World's Deadliest 'Funnel-Web' Spider Can Change Potency Of Its Venom As Per Its Mood

Scientists have found that the venom of the world's deadliest spider, 'Funnel-webs' seems to vary depending on context.

According to the Australian Museum, funnel-web spiders are considered the spider fauna's most notorious members. They can be seen across eastern Australia.

Dr Linda Hernandez Duran from James Cook University Australian Institute of Tropical Health and Medicine says that factors such as the spider's heart rate and defensiveness could play a role in the proportions of chemicals delivered on the ends of the fans of an angry spider, reported Science Alert.

Dr Duran examined the venom produced by different species of funnel-web under different conditions. She said funnel webs are the most venomous spiders in the world.

She explained, "Funnel webs have the most complex venoms in the natural world, and they are valued for the therapeutics and natural bioinsecticides that are potentially hidden in their venom molecules. Knowing more about how they are produced is a step towards unlocking this potential."

The team of scientists tested four different species of the deadliest spider including the Border Ranges (Hadronyche valida), Darling Downs, (Hadronyche infensa), Southern tree-dwelling (Hadronyche cerberea) and Sydney funnel-web (Atrax robustus).

"We mapped their behaviour and measured their heart rate with a laser monitor to establish a proxy value for their metabolic rate. We then collected their venom and analysed it with a mass spectrometer," said Dr Duran.

The doctor explained that certain spiders had variations in their venom based on different factors such as defensiveness and heart rate.

"With the Border Ranges funnel-web, the expression of some venom components was associated with heart rate and defensiveness. The other species didn't demonstrate this, suggesting that particular associations may be species-specific," said Dr Duran.

Dr Duran explained that the use of venom and the display of aggressive behaviours by spiders have metabolic costs.

"As a result, spiders might use different behavioural strategies to compensate for these costs. Our results suggest spiders might increase their metabolic rate when they use venoms, and reduce their movement when facing a threat," said Dr Hernandez Duran.

She said the findings highlight the link between behaviour, physiology, and venom composition in funnel webs.