18 new species of pelican spiders discovered

Newly described arachnids are itsy-bitsy spider-killing machines native to Madagascar

pelican spider

WELL PRESERVED  Eriauchenius milajaneae is a new species of pelican spider discovered by arachnologist Hannah Wood, who named it after her daughter “in the hope that one day she will go to Andohahela [National Park in Madagascar] to find this spider,” Wood writes in a new paper describing 18 new species.

H. Wood/Smithsonian

Despite their name, pelican spiders aren’t massive, fish-eating monstrosities. In fact, the shy spiders in the family Archaeidae are as long as a grain of rice and are a threat only to other spiders.

Discovering a new species of these tiny Madagascar spiders is tough, but Hannah Wood has done just that — 18 times over.

Wood, an arachnologist at the Smithsonian National Museum of Natural History in Washington D.C., analyzed the genes and anatomy of live and museum pelican spider specimens to find these new species. She describes them in a paper published online January 11 in ZooKeys.

Like other pelican spiders, the new species have an elongated “neck” and beaklike pincers, or chelicerae. The way they use those long chelicerae to strike from a distance, earned them another name: assassin spiders. Once impaled, the helpless prey dangles from these meat hooks until the venom does its work (SN: 3/22/14, p. 4).

Probing the spiders’ tiny anatomy under a microscope, Wood looked for hints to distinguish one species from another. Arachnologists often look to spiders’ genitals: Males and females from the same species typically evolved specially shaped organs to mate. If the “lock” doesn’t fit the “key,” the spiders are likely of a different species.

Thanks to Wood, 18 more species of pelican spiders — some of which were previously misclassified — now have names. Eriauchenius rafohy honors an ancient Madagascar queen, and E. wunderlichi, an eminent arachanologist. Wood, one of the foremost experts on pelican spiders, says she expects there are still more species to find. Perhaps an E. woodi?

FANGS A LOT Pelican spiders, like this Eriauchenius workman, get their common name from their unusual looks. Beaklike pincers let it hold another spider — dinner — in its venomous jaws. Nikolaj Scharff

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