The environmental preference of mesopelagic shrimp Pasiphaea japonica in the shelf waters of southern East China Sea

The mesopelagic shrimp Pasiphaea japonica is one of the species composition in the sergestid shrimp trawler fisheries in the shelf waters of south East China Sea. A multidisciplinary survey using the acoustic, biological, and hydrographic data was carried out for evaluating the potential habitat of P. japonica using the generalized additive models (GAM). Acoustic characteristics of diel vertical distribution for mesopelagic shrimp P. japonica at smaller (31~44 mm) and bigger (44~51 mm) mantle length sizes were examined. In daytime, the bigger and smaller size shrimp like to inhabit at different depth layers where the water temperatures were approximately 15.5 ℃ and 16.2 ℃, respectively. It suggested that the habitat depth of bigger shrimp is deeper than that of small shrimp. In nighttime, the spatial distribution of the bigger shrimp was suggested to relate the dissolved oxygen c.a. 5.8 ppm. The environmental preference of shrimp in the water temperature, salinity, illuminance and Chlorophyll-a are suggested to be approximately 24~25 ℃, 34, 0.0001~0.005 μmol/m²/s and 0.19 mg/m³, respectively. The results would allow local information for mesopelagic shrimp P. japonica in order to implement appropriate ecosystem-based fisheries management program in the future.