Identification:
The species is a large mantis shrimp, reaching up to 25 cm in length, with a flattened body. The eye sockets are located at the front lateral corners. The anterior lateral margin has only one broad cervical notch, with two teeth anterior and posterior. The dorsal surface is covered with evenly distributed rounded spots, with two paired arc-shaped markings; a central longitudinal ridge runs along the back and extends to the abdominal segments. The abdominal segments taper towards the rear, and have a central dorsal ridge and transverse grooves.
Biology and Ecology:
Mating and egg-laying occur from December to April of the following year, with peak spawning in March. The species inhabits depths of 8-70 meters. In Vietnamese waters, it is typically caught at depths of 10-25 meters, over soft bottoms composed of sand, mud, and shell debris.
Distribution:
Vietnam: Found from the offshore waters of Quảng Ninh to Kiên Giang. Areas with relatively high densities of this mantis shrimp include the waters around Cù Lao Thu (Bình Thuận) and from Cà Mau to Phú Quốc Island (Kiên Giang), with the highest densities reaching approximately 1000 individuals/km².
Global: Japan, China, Philippines, Australia, East Africa, and the Red Sea.
Value:
It has significant scientific research value in Vietnam. Prior to 1975, it was commonly caught throughout Vietnamese waters, especially in the South Central Coast and from Cà Mau to Kiên Giang. The mantis shrimp had a considerable yield and was considered an important target for fishing. After 1975, especially from 1990 to the present, increased harvesting to meet domestic food demands and for export has led to a noticeable decrease in production, potentially up to 20%.
Conservation Status:
- Before 1975, the distribution area of the mantis shrimp was extensive, covering nearly all offshore waters of Vietnam, approximately 20,000 km². Currently, due to increased harvesting, its distribution area has shrunk to below 20,000 km².
- IUCN Red List: VU A1d B2a+3d.
Conservation Measures:
The species needs to be included in the list of species requiring protection by the fisheries sector, and harvesting should be managed through rotating fishing grounds.