Scorpions Use Different Venom Cocktails Depending On The Type Of Animal They Are Attacking
You would think that scorpions only inject their victims with one single type of venom. However, researchers have known for a while that scorpions contain three different subtypes of venom. The three different toxic chemicals that make up scorpion venom may be mixed in ways that either reduce or or increase the potency of their venom. For example, if a scorpion is hunting its prey, which are insects, then they will likely use a mix of venom that is strong enough to kill a small insect, but not strong enough to kill a mammal. Since scorpion predators are often mammals, then scorpions will likely have to use a particularly potent mix of chemicals in order to subdue large predatory mammals during defensive attacks. Do scorpions change the composition of their venom in order to match the animals that they are attacking? Does scorpion venom change composition depending on the relative dangerousness of their environments? Or is the particular composition of chemicals in a scorpion’s venom fixed? In order to answer these questions Dr Jamie Seymour from James Cook University’s Australian Institute of Tropical Health and Medicine has conducted some clever experiments.
Seymour’s team also included ecologists, chemists, and physiologists from the graduate school. The team of scientists separated scorpions into different groups. One group was placed in an environment with a dead cricket, and another group was placed with a live cricket. The third group was placed with a mammal that resembled a mouse. The stuffed mouse was lifelike and simulated threats against the scorpion.
Not surprisingly, the researchers discovered that the scorpion exposed to the mammalian threat produced a venom cocktail that was more lethal to mammals. The scorpion’s venom also contained less of a chemical that would be more effective at killing insects. The different venom compositions did not necessarily mean that some were more potent than others; instead some particular blends of venom were more effective at attacking particular types of nervous systems. Based on these results Seymour and his colleagues demonstrated that scorpions, and probably other organisms, can change the composition of their venom in response to a threatening environment.
Do you think that the change in venom composition is immediate or gradual in scorpions?