Scientists discover rare spider that is half-female and half-male

Scientists discover rare spider that is half-female and half-male

Mangalore Today News Network

Thailand, Nov 11, 2025: Scientists recently found a new species of spider in Thailand with fascinating traits. The spider is half-male and half-female. Researchers were left stunned to find the rare spider’s body is perfectly divided into two parts, one bright orange and the other half is in a grey tone, and both sides display different characteristics. The spider has been identified as Damarchus inazuma.

The findings marked the first recorded instance of gynandromorphism in the Bemmeridae family and only the third known case in the mygalomorph group, which includes tarantulas. Gynandromorphism is a rare biological phenomenon where an individual organism has both male and female tissues and characteristics.

The study, published in the journal Zootaxa, revealed that the spider’s body is divided symmetrically, with the left side displaying female traits, while the right side exhibiting male characteristics. The female traits include larger fangs and orange colouration, and male traits consist of smaller size and greyish-white colour.

This striking appearance has earned it the name Damarchus inazuma, inspired by a character from the anime One Piece who can switch between male and female forms.

Local naturalists found the spider in a forest area near Nong Rong, Thailand, while digging for predators. The unique gynandromorphic traits of the spider were studied by researchers from Chulalongkorn University.

"I am indebted to numerous individuals for this discovery, particularly Mr. Surin Limrudee," study’s lead author, entomologist Chawakorn Kunsete, said as quoted by Forbes.

Kunsete, who is a doctoral student of biology at Chulalongkorn University, is working under the mentorship of the study’s senior author, entomologist Natapot Warrit, an assistant professor at Chulalongkorn University.

"His Facebook post featuring a photograph of a gynandromorph spider immediately captured my interest," Kunsete told he media outlet in an email.

"Upon contacting him, I discerned that the specimen was not only a gynandromorph but also morphologically distinct from any previously described species. This prompted me to seek collaboration with Mr. Limrudee and other colleagues. Through the collection and analysis of additional specimens, we were able to confirm that the specimen indeed represents a new species."

The team believes the condition may result from disruptions in sex chromosomes during early development, possibly influenced by environmental factors or parasites.

Is the spider poisonous?

"There are no formal studies concerning the venom of this species, nor are there documented bite records," Kunsete said as quoted by the report.

"However, related families, such as Theraphosidae and Barychelidae, are known to possess venom glands. Moreover, during fieldwork, we frequently observed this spider exhibiting aggressive displays, including the baring of fangs and occasionally the production of droplets at the fang tips. Based on these observations, I infer that the species is probably venomous (to small insects?)."