Even the tiniest organisms can make it to the big leagues. The number one fastest animal movement in the world now belongs to an ant no bigger than the tip of your finger.
Ominously named the Dracula ant (Mystrium camillae), this minuscule species is shy and elusive, a subterranean predator that enjoys sucking the blood from its own hapless larvae in a practice fondly known as “nondestructive cannibalism“.
It’s also wicked fast. A new study has found that the jaws on this rare and mysterious species can snap shut five thousand times quicker than the blink of an eye.
Using a high-speed camera, scientists at the Smithsonian have now caught this remarkable movement in action for the first time.
The mechanism works sort of like a finger snap, except at a meteoric pace, one thousand times faster than what human hands are capable of.
Pressing the tips of its mandibles together, pressure between the ant’s jaws begins to build, until at last it reaches a breaking point, eventually releasing one of3 the mandibles so it slides across the other.
From start to finish, the action takes 0.000015 seconds, going from zero to around 320 kilometres an hour in a fraction of an instant.
This particular species of Dracula ant has now taken the gold medal for the fastest known animal appendage and the fastest known biological manoeuvre ever.
The genus Mystrium has been called the “most mysterious group within the bizarre Dracula ants”, and scientists are still not sure why this cryptic ant has evolved such special mandibles.
Although, in the animal kingdom, when it comes to catching prey and avoiding predators, speed is extremely important. Today, the fastest known movements are behaviours based on hunting and defence, and these quick twitches are commonly observed in arthropods like mantis shrimp, froghoppers and trap-jaw ants.
Among these creatures, energy is stored up in the muscles and then released via a latch that lets the energy loose through some sort of elastic spring. By incorporating latches and springs, these animals are saved from overworking their muscles, and this allows creatures like the Dracula ant to forage for food and defend themselves against predators in the most efficient way possible.
Even compared to other trap-jaw ants, however, the Mystrium Dracula ant reigns supreme. Currently, we know at least six lineages of ants that have similar power-amplified mandibles, but the Mystrium camillae has a unique morphology that makes it especially quick.
Unlike other ants with trap-jaws, the mandibles on these fellas start from a closed position and then slide across each other. What’s more, the spring and latch mechanisms that allow the jaw to slam closed are embedded within the mandible itself.
This unique structure is probably what gives this genera such speed. In trap-jaw ants like the Odontomachus and Myrmoteras genera – where the spring, latch and trigger structures are separated – it takes three to sixty times longer for the jaws to close. And even at peak velocity, this movement is still ten to twenty times slower than what Mystrium camillae is capable of.
The authors of the paper think that maybe these special jaws developed alongside this ant’s unique underground habitat – in the tropics of South East Asia and Australia – where open jaws are not really an option.
“The foraging and nesting habits of Mystrium are also restricted to confined tunnels in logs and in the soil, and this may favour this type of amplification system where the ant cannot open its jaws widely as seen in trap-jaw ants which largely forage in open spaces,” the authors propose.
But we still can’t be sure. These creatures are like buried treasure, and more research will be needed if we want to know why they have developed such expeditious trap-jaws.
This study was published in the Royal Society Open Science (link not yet live at time of publishing this article).