Damarchus inazuma: New Half-Male, Half-Female Spider Species Discovered in Thailand

Damarchus inazuma: New Half-Male, Half-Female Spider Species Discovered in Thailand

Bangkok, Nov 12: Scientists in Thailand have identified a remarkable new species of spider that’s literally split down the middle — half male and half female. The discovery has fascinated researchers, who say the spider’s body is perfectly divided into two distinct halves: one bright orange and the other grey.

The species, named Damarchus inazuma, represents the first known case of gynandromorphism — a condition in which an organism exhibits both male and female traits — in the spider family Bemmeridae. It’s also only the third such instance ever recorded among mygalomorph spiders, a group that includes tarantulas.

According to a study published in the journal Zootaxa, the spider’s left side displays female characteristics, such as larger fangs and a vivid orange hue, while the right side bears male traits, including a smaller body and a greyish-white color.

The species’ name draws inspiration from a character in the popular anime One Piece who can switch between male and female forms — a nod to the spider’s striking duality.

Discovery in the Wild

Local naturalists stumbled upon the spider while digging in a forested area near Nong Rong, Thailand. The unusual find was later examined by researchers from Chulalongkorn University, who confirmed its rare gynandromorphic features.

“I’m indebted to many people for this discovery, particularly Mr. Surin Limrudee,” said Chawakorn Kunsete, the study’s lead author and a doctoral biology student at Chulalongkorn University, in comments reported by Forbes.

Kunsete said Limrudee first caught his attention after sharing a photo of the spider on Facebook. “When I contacted him, I realized the specimen wasn’t just a gynandromorph — it was morphologically distinct from any known species,” he explained. “That prompted me to collaborate with Mr. Limrudee and other colleagues. After analyzing additional specimens, we confirmed it was indeed a new species.”

Kunsete worked under the supervision of Assistant Professor Natapot Warrit, who co-authored the study.

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A Rare Biological Mystery

Researchers believe the spider’s unusual split-sex traits could result from irregularities in sex chromosome division during early development — possibly influenced by environmental factors or parasites. Gynandromorphism, though documented in butterflies, birds, and crustaceans, remains exceptionally rare among spiders.

Is It Venomous?

There’s little data on whether Damarchus inazuma poses a threat to humans. “There are no formal studies concerning the venom of this species, nor any documented bite records,” Kunsete said.

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He noted, however, that related spider families — including Theraphosidae and Barychelidae — are known to have venom glands. “During fieldwork, we often observed this spider displaying aggressive behavior, baring its fangs, and even producing droplets at the fang tips,” he added. “Based on those observations, it’s probably venomous — at least to small insects.”

For now, scientists say, the vivid two-toned spider stands as both a biological curiosity and a reminder of nature’s unpredictable complexity.