Scorpions’ poison matched to threats

JAMES Cook University scientists have discovered that scorpions can change their venom in response to a threat.

The research team of ecologists, chemists and physiologists kept Australian rainforest scorpions under different conditions, testing how they responded to different predators and prey.

Dr Jamie Seymour from JCU’s Australian Institute of Tropical Health and Medicine said a scorpion predator could be a small mammal, while its prey was usually an insect.

He said varieties of scorpion toxin worked better depending on whether they were used to protect themselves from predators or kill prey.

“Scorpions contain three separate subtypes of toxins that are effective against mammals only, insects only, and both,” he said.

After six weeks of the project, scorpions exposed to a simulated predator exhibited significantly different venom chemistry compared with those not exposed to predators.

Dr Seymour said as far as the researchers could tell, it was the first time it had been shown that venom chemistry in organisms could change in response to a threat.

“It implies a rerouting of nutritional or energetic resources by the scorpion to increase relative production of different venom fractions which are responsible for toxicity to invertebrates,” he said.