Bangkok – A team of researchers in Thailand has announced the discovery of a new species of spider featuring an exceptionally rare biological trait: a “gynandromorph” — an organism that is half male and half female, divided symmetrically down the middle. The spider was found near a forested area in Kanchanaburi province, in western Thailand, and is believed to belong to the Damarchus genus, commonly known as “wishbone” or “mygalomorph” spiders.
Scientists from the Chulalongkorn University Museum of Natural History conducted an in-depth analysis of the species, which is still undergoing genetic confirmation. The findings, published in the scientific journal Zootaxa, highlight the specimen’s striking bilateral sexual dimorphism, with one side of its body exhibiting male traits and the other side female traits.
The male specimen measured about 0.6 inches (1.5 cm), appeared grey, and was covered in a white, unidentified substance. The female measured about one inch and was bright orange without the coating. The newly discovered species has been named Damarchus inazuma, inspired by the “One Piece” manga character Inazuma, who has the ability to switch between male and female forms. The spider displays orange coloration on the left side and white on the right, mirroring the natural differences between males and females of the species.
“This color arrangement closely mirrors the sexual dimorphism observed in this species, with males exhibiting white coloration and females displaying orange,” the researchers wrote.
These spiders construct wishbone-shaped, silk-lined burrows in the ground, ambushing prey from their underground lairs. While sexual dimorphism is common in many species, gynandromorphy is extremely rare, particularly in arachnids. Unlike hermaphrodites, which naturally possess both reproductive organs symmetrically, gynandromorphs exhibit split male-female characteristics on each side of their body.
“Gynandromorphy is a rare phenomenon observed in the animal kingdom,” the research paper noted. “To confirm the presence of gynandromorphism, traits of both sexes, such as genitalia, must be present within the same individual, usually displaying bilateral asymmetry.”
The discovery of Damarchus inazuma adds valuable insight into sexual development and differentiation in arachnids, while also drawing attention to the rich biodiversity of Southeast Asia, an area still yielding significant scientific discoveries.