Geosesarma bunian — a mystical-looking freshwater crab species found high in Malaysia’s northern highlands Gunung Jerai
Gunung Jerai has once again drawn attention after researchers confirmed the discovery of a new freshwater crab species from the genus Geosesarma, now named Geosesarma bunian.
This fascinating discovery originates from the northern region of Peninsular Malaysia, contributing to the country’s growing biodiversity, particularly within the rarely explored highland ecosystems.
Geosesarma bunian is now listed alongside four other species in the Geosesarma foxi group: three from Malaysia — G. foxi sensu stricto (Langkawi Island, Kedah), G. serenei Ng, 1986 (Bukit Larut, Perak), and G. faustum Ng, 2017 (Penang Island); and one from Narathiwat, Thailand — G. todaeng Ng, Yeesin & Promdam, 2023.
This newly recorded species was found at an elevation exceeding 1,100 meters above sea level in the misty, cool highlands of Gunung Jerai, Kedah — an ideal environment for a mysterious species like the bunian crab.
Although it is no larger than a 50-sen coin, Geosesarma bunian is striking in appearance — its front half displays a yellowish hue, while the back is dark bluish-grey adorned with small white spots.
The name was inspired by the mythical “Orang Bunian” from Malay folklore, reflecting the crab’s elusive nature. It typically inhabits small soil burrows along slopes and has even been spotted on shrub branches — suggesting possible semi-arboreal behavior. Intriguingly, it has also been seen coexisting with large forest spiders.
Beyond its appearance, Geosesarma bunian is unique in its body structure and reproductive traits. So far, it has only been found in Gunung Jerai, indicating a very limited distribution — potentially classifying it as a rare species.
Researchers emphasized that this discovery serves as a critical reminder of the importance of conserving highland forests. Gunung Jerai is not just a recreational site but also a vital sanctuary for unknown species yet to be discovered.
One important note — if you happen to spot this crab during a hike, do not disturb or take it home. Let it continue ‘hiding’ peacefully in its natural habitat.
The official documentation of Geosesarma bunian was published in the Raffles Bulletin of Zoology by Peter K. L. Ng from the National University of Singapore, together with Malaysian researchers Khadijah Ahmad and Prof. Amirrudin B Ahmad from Universiti Malaysia Terengganu.
By Tarziman — 09 May 2025, 03:16 PM
