With the decline in fish resources worldwide, the ecological dominance and economic importance of crustaceans have obviously increased. Among crustacean species, mantis shrimps are increasingly dominant in many coastal waters of the world. In China, Oratosquilla oratoria is the most widely distributed and productive species of mantis shrimp, and its relative resource density is the highest in the Bohai Sea. In this study, we analysed the long-term and monthly population characteristics of O. oratoria in the Bohai Sea, including its relative resource density, body size and spatial distribution. The results showed that the relative resource density of O. oratoria in the Bohai Sea increased from 3.59 kg/h in 1982 to 14.48 kg/h in 2018, and the percentage of this species that serves as a fishery resource increased from 4.22％ in 1982 to 35.27％ in 2018, based on the mean relative resource density in May and August. The relative resource density of O. oratoria in the fishing moratorium season from May to August was significantly higher than that in the other months of fishing season, and the relative resource density decreased rapidly after the fishing moratorium ended. The relative resource density of O. oratoria was the highest in summer (August), followed by in autumn (October) and spring (May), and it was the lowest in winter (January). The relative resource density of O. oratoria in the western Bohai Sea was higher than that in the eastern Bohai Sea. The mean body weight of O. oratoria in the Bohai Sea decreased from 21.95 g in 1982 to 14.34 g in 2018, based on the mean body weight in May and August. The body size of O. oratoria in the fishing moratorium season was significantly higher than that in the fishing season, and the body size decreased rapidly after the fishing moratorium ended. Overall, in the context of declining resources of most fishery species, the relative resource density of O. oratoria increased due to its hardiness and adaptability, and its body size decreased under intensive fishing over the past 30 years. The fishing moratorium system had a great influence on the population dynamics of O. oratoria in terms of the relative resource density and body size in the Bohai Sea.

Qiang Wu;Qingpeng Han;Yue Jin;Tao Yang;Zhongyi Li;Xiujuan Shan;Xianshi Jin

Key Laboratory for Sustainable Development of Marine Fisheries,Ministry of Agriculture and Rural Affairs/Shandong Provincial Key Laboratory for Fishery Resources and Eco-environment,Yellow Sea Fisheries Research Institute,Chinese Academy of Fishery Sciences,Qingdao 266071,China;Laboratory for Marine Fisheries Science and Food Production Processes,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China;Fisheries College,Ocean University of China,Qingdao 266003,China

海洋学报（英文版）

[1]Qiang Wu;Qingpeng Han;Yue Jin;Tao Yang;Zhongyi Li;Xiujuan Shan;Xianshi Jin-.Long-term and monthly changes in abundance, size composi-tion and spatial distribution of the mantis shrimp Oratosquilla oratoria in the Bohai Sea)[J].海洋学报（英文版）,2022(12):80-86

mantis,hardiness

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