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A new species of spider was recently discovered near a forested area in Nong Rong, Phanom Thuan, Kanchanaburi, in western Thailand. The spiders were presented to researchers at the Chulalongkorn University Museum of Natural History, where they were studied further.

After analyzing the specimens under a stereomicroscope and comparing them to similar species, the group determined the spiders to most likely be a part of the genus Damarchus—a group of mygalomorph, or "wishbone," spiders found in South and Southeast Asia. This group of spiders is known for the wishbone-shaped burrows that they make in the ground, where they wait for prey. While the features of the new species fit best into the genus Damarchus, molecular data have not yet confirmed this.

The group describes the new species in their paper in the journal Zootaxa. One of the most striking aspects of the newly discovered species is the stark differences between the male and female spiders.

The male of the species is only around 0.6 inches in length, while the female is typically around one inch in length. The males appear gray in color and are covered in a white substance that is yet to be identified. When the male is preserved in alcohol, it appears as a reddish-brown color. The females, on the other hand, are a brighter orange color and lack the white layer of unknown substance.

An even more striking discovery was the gynandromorph specimen found in the set. Gynandromorphs are rare organisms that are half-male and half-female, where each side of the body presents differently, split right down the middle. Gynandromorphs are distinct from hermaphrodites in that hermaphrodite organisms still have bilateral symmetry and naturally have both sex organs. Hermaphroditism is common in some organisms, while gynandromorphism is much rarer.

The gynandromorph specimen shows a distinct split between the features of both the male and female species. This earned the species its name.

"The species is named after Inazuma, a character from the Japanese manga 'One Piece,' known for the ability to change sex between male and female. The Inazuma style is characterized by bilateral asymmetry, presenting distinct coloration with orange on the left side and white on the right side. This color arrangement closely mirrors the sexual dimorphism observed in this species, with males exhibiting white coloration and females displaying orange," the study authors write.

This is the first-ever report of a gynandromorph in the family Bemmeridae, to which Damarchus belongs. Only two previous cases of gynandromorphism have been reported in mygalomorph spiders, both in the Theraphosidae family.

"Based on reported cases, it can be inferred that our specimen of gynandromorph corresponds similarly to the first case described, characterized by bilateral asymmetry and the manifestation of both sexes on opposite sides. However, the definitive cause of this gynandromorphism remains uncertain. Kaston suggested that gynandromorphism may arise from the loss of two or more sexual X chromosomes (a chromosomal disorder) in the female zygote, potentially induced by various natural factors, including nematode infection," the authors say.

These new findings of not only a new species, but also a gynandromorph in their midst, represent a rare and exciting biological discovery.

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