Half-male, half-female spider discovered in Thailand

MMost living things on Earth live in the shadows, unbeknownst to science. Even conservative estimates estimate that only 13 to 18 percent of organisms have been identified and described. The task of discovering, describing and naming these species may seem daunting, but for scientists seeking to bring order to this chaos, there are always surprises. This was the case for a team of researchers who discovered a previously unknown species of spider, hidden in the forests of western Thailand. Not only did they find a species that had escaped the attention of the scientific enterprise, but they found a rare individual, half male and half female.

The species, described for the first time in the journal Zootaxa by scientists at the Center of Excellence in Entomology at Chulalongkorn University in Bangkok, shows striking physical differences between the sexes. The female is larger (about an inch in length) with a distinct orange coloring, while the male is about half that size and appears gray due to a mysterious white substance covering its body.

The individual could be the result of loss of sex chromosomes due to nematode infection in a female embryo.

Among the orange and gray arachnids collected by the research team was a strange specimen, half orange and half gray. Researchers studied this specimen and discovered that this particular spider was a rare gynandromorph.

Gynandromorphs differ from the relatively more common hermaphrodites in some key ways. Although hermaphrodites possess both female and male sexual organs, they still display normal bilateral symmetry: the two halves of the organism appear as mirror images. Gynandromorphic individuals, on the other hand, exhibit asymmetry; one side is feminine, while the other is masculine. Although the causes of this specimen’s gynandromorphy are unknown, the authors state that the individual may be the result of loss of sex chromosomes due to nematode infection in a female embryo.

Such a colorful spider deserves a colorful name, and scientists have given this species a particularly fitting name. The researchers named their discovery Damarchus Inazuma based on the character Inuzama from the manga One piece for several reasons. First, Inuzama, the character, possesses the power to change from a feminine presentation to a masculine presentation. Secondly, like the D. exam gynandromorphic, Inuzama is always dressed in orange and white, split down the middle.

Assuming that the researchers’ classification D. inuzama is confirmed by molecular data, this is the first documented example of gynandromorphy in Bemmeridae, a family of funnel-shaped trapdoor spiders widespread in Asia and Africa.

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Main image: Damarchus Inazuma: Fig 6a: Kunsete et al., 2025:
https://doi.org/10.11646/zootaxa.5696.3.6). ©Magnolia Press. Reproduced with permission of the copyright holder.

• Jake Currie

  Published on October 16, 2025

  Jake Currie is a writer based in Brooklyn, New York.