Identification:
The carapace is flattened and smooth, with a wide transverse dimension. The median grooves and semilunar grooves are clearly visible, while the frontal grooves are indistinct. The forehead is narrow, with the anterior margin divided into two lobes. The walking legs are slender and elongated. The terminal segment of the abdomen is low and triangular, with a nearly pointed apex.
Biology and Ecology:
This species inhabits rivers and streams in mountainous and midland regions adjacent to mountains.
Distribution:
- Within Vietnam: Thai Nguyen (Ky Phu), Bac Kan, Hoa Binh (Chi Ne), South Central Coast (Phuc Son).
- Worldwide: Endemic to Vietnam.
Value:
This is an endemic species with value as a food source.
Conservation Status:
The distribution range is fragmented. The estimated distribution area before 1975 was less than 20,000 km². Due to overexploitation, the distribution area has decreased, and the habitat has significantly diminished. Recent surveys and studies have rarely encountered this species.
IUCN Red List Category:
VU B1+2a,b,e (Vulnerable)
Conservation Measures:
Listed in the Vietnam Red Book. Recommendations include limiting exploitation and conducting research on biological, ecological characteristics, and population distribution.