Abstract:

We studied the shrimp and crab community and species biodiversity by performing a survey of the bottom-trawling fishery resources in the eastern Nanji Islands National Marine Nature Reserve in November 2017 and May 2018. The results indicated that: (1) A total of 30 shrimp and crab species were identified, including 16 shrimp species belonging to 12 genera in 6 families of one order, and 14 crab species belonging to 6 genera in 5 families of one order. (2) The number of shrimp and crab species was higher in autumn than in spring, and there were gradually more species as we traveled southward across the survey area in both seasons. (3) Dominant species in the spring were Portunus trituberculatus, Charybdis bimaculata, Alpheus juponicus, Parapenaeopsis tenella and Charybdis japonica. Dominant species in the autumn were Portunus trituberculatus, Charybdis bimaculata and Charybdis japonica. There were no dominant shrimp species in the autumn. (4) The Shannon-Wiener diversity index and the Pielou’s evenness index were higher in the spring than in the autumn. The species richness index was much higher in the autumn than in the spring. (5) According to hierarchical cluster and non-metric multidimensional scaling (nMDS) analyses, shrimp and crabs can be divided into three communities. (6) The abundance-biomass comparison curve (ABC curve) showed that the shrimp and crab communities were stable and undisturbed.

Key words: shrimp and crab, biodiversity, community structure, the east of Nanji Islands