A newly discovered intersex spider in western Thailand has caught the attention of scientists due to its rare mix of both male and female features. Found in the forested area of Kanchanaburi province, the spider was part of a collection submitted by local residents to researchers at Chulalongkorn University’s Museum of Natural History.
Among the group of spiders, one stood out for its unusual body: one half showed traits typical of a male, while the other side displayed features common to a female. This rare condition is known as gynandromorphism, and it has only been recorded a few times in spiders across the world.
The unique specimen belongs to the Bemmeridae family, a group of ground-dwelling spiders common in South and Southeast Asia. According to scientists, this marks the first known instance of a gynandromorphic spider within this particular family. Previously, only two similar cases had been recorded, both from a different spider group.
Striking appearance and manga-inspired name
The spider’s physical appearance is as remarkable as its biology. One side of its body was bright orange, while the other was pale gray — colors that match how males and females typically look in this species. The visual split was so distinct that it resembled two spiders merged into one.
Because of its vivid color contrast and gender-fluid traits, the research team decided to name the species after Inazuma, a character from the popular Japanese manga One Piece. The fictional character is known for changing gender and wearing clothes that reflect both masculine and feminine styles. Scientists said the character’s appearance and qualities closely matched the spider’s unique features.
New insights into spider biology
While researchers have confirmed that the spider belongs to the Damarchus genus — burrowing spiders known for building Y-shaped tunnels — they are still analyzing its genetic makeup to confirm its exact classification.
The male spiders of this species are usually smaller, with grayish coloring and a mysterious white coating that turns reddish when preserved. In contrast, females are nearly twice the size and display a bright orange hue without the coating.
As for what caused the unusual development, the exact reason remains unknown. However, past studies suggest it may happen early in life due to genetic issues, possibly influenced by environmental factors such as parasites.
The discovery not only adds to the limited number of known gynandromorphic spiders but also provides new insight into how spiders develop and differentiate by sex. Scientists say more research will help explain how common this rare trait might be in nature.