April 7, 2014 | 1
Time to dust off those tuxedos and meet me at the Blood Bar in five, because we’ve got six new species of Dracula ants to discuss.
Species belonging to the Amblyoponinae subfamily of ants from Madagascar have earned the nickname ‘Dracula ants’, thanks to a social feeding system that involves the queens and workers feeding off the blood, or haemolymph, of their young. Known as ‘non-destructive parental cannibalism’ because the young don’t end up dead, just full of holes, this behaviour sees scores of worker ants gorging themselves on the vital fluids of the colony’s young before regurgitating it up and feeding it to the sedentary and wingless queens. More commonly, ant species prefer to take the non-cannibalistic route towards social feeding, with the workers sharing bits of solid food they’ve collected with each other and the queen.
The larval victims of the Amblyoponinae Dracula ants are usually in their final stages of development before reaching adulthood (so are probably filled with the most haemolymph), and will show signs of puncture wounds and scarring across their bodies. Other than that, they’re left unharmed. Unless of course the colony is starved, in which case the workers will usually pick off the most exploited/drained/scarred larvae as an emergency food source.
Within the Amblyoponinae subfamily, the genus Mystrium contains the most bizarre and entirely unique species of Dracula ants. With a name that recalls the uncertainty surrounding their general biology, ecology and behaviour, Mystrium ants are rare and hard to locate, because they tend to live out their days in a mass of leaf litter, or under rocks and dry logs. They’re native mostly to tropical Africa, with a bunch of them found in the thick, humid forests of Madagascar, but a few species have also been found in the Indo-Australian region, including in Singapore, the Philippines and New Guinea.
After spending more than two decades collecting thousands of Mystrium ants in Madagascar and its surrounding islands, Brian L. Fisher, Curator of Entomology at the California Academy of Sciences, teamed up with postdoc researcher, Masashi Yoshimura, to classify them. One rigorous revision of the genus and a new taxonomic framework later, Fisher and Yoshimura ended up with six new species of Mystrium Dracula ant. They’ve published their descriptions in the latest edition of Zookeys.
According to Yoshimura, three of the new species’ names – Mystrium labyrinth, Mystrium mirror, and Mystrium shadow – were assigned to “evoke the air of mystery around this genus”, but what they also evoke is the air of elite ninja ant triplets. You think regular elite ninja ants are dangerous, just wait till you’re the target of elite ninja ants who happenn to share familial bonds. Imagine how coordinated their ninja star trajectories would be. Your best bet is to just surrender your haemolymph by putting a fresh glass out each night with a couple of cookies and a bucket of whatever the elite ninja ant version of a dozen airborne reindeer eat.
Not only do Yoshimura and Fisher’s Dracula ants have an unusual way of feeding themselves, they also have some pretty strange exteriors. Mystrium ants are the only ants in the known world to have evolved super-long, snapping jaws. Lined with rows of jagged teeth, these jaws, or mandibles, can snap over each other within about 0.5 milliseconds. Which is faster than the naked eye or a regular video camera could hope to take in. And while that sounds like a pretty great weapon, researchers have widely suggested that it more likely acts as a defense mechanism.
In 1998, Wulfila Gronenberg and Bert Holldobler from Theodor Boveri Institut in Germany and Gary D. Alpert from Harvard’s Museum of Comparative Zoology studied the jaw snapping of Mystrium rogeri ants from Madagascar. They found that by snapping their enormous jaws super-fast at whatever’s threatening them, Dracula ants can generate a powerful and intimidating strike, just like if we walked up to someone and snapped our fingers in their face. But because ants are working on a much tinier scale, these snaps can be incredibly powerful, with enough force to physically propel any threats away from the nest:
“We have observed other cases where ants snapped themselves away for more than 10 cm, a large distance for such a small animal. However, under natural conditions small arthropods about the size of Mystrium are the probable intruders against which the mandible snap is employed. They would be stunned and catapulted out of the nest entrance by the snap.”
Someone make a video game about vampire ninja ants wielding shockwave-powered twin scythes immediately.
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