Page 102 - 《水产学报》2025年第7期

肖泽宇，等 水产学报, 2025, 49(7): 079308

Habitat use history of Coilia nusus in Oujiang River Estuary
based on otolith microchemistry

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XIAO Zeyu , LIU Mingzhi 1,2,3 , SHAN Xiaoluan , JIANG Rijin , YIN Rui , LI Zhenhua ,
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JIANG Tao , ZHU Shuailin , WANG Haoran , SHEN Jiarong 1,2
1. Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan 316021, China;
2. Key Laboratory of Sustainable Utilization of Technology Research for Fishery Resources of Zhejiang Province,
Scientific Observing and Experimental Station of Fishery, Resources for Key Fishing Grounds,
Ministry of Agriculture and Rural Affairs, Zhejiang Marine Fisheries Research Institute, Zhoushan 316021, China;
3. Ocean College, Zhejiang University, Zhoushan 316021, China;
4. Rushan Marine Economic Development Center, Rushan 264500, China;
5. Laboratory of Fishery Microchemistry, Freshwater Fisheries Research Center,
Chinese Academy of Fishery Sciences, Wuxi 214081, China

Abstract: Coilia nasus, an ecologically and economically important anadromous fish species in China, exhibits a typical river-
ine migratory life-history strategy. The Oujiang River Estuary, a representative macrotidal estuary in southern Zhejiang
Province, is characterized by highly dynamic hydrological and salinity gradients, which exert significant influence on the hab-
itat selection and life-history strategies of C. nasus. To elucidate the "habitat use history" of this species and better understand
its migratory and developmental patterns, this study employed electron probe micro-analysis (EPMA) to analyze the micro-
chemical composition of strontium (Sr) and calcium (Ca) in the otoliths of 15 C. nasus specimens collected from the estuary.
The results demonstrated substantial variation in Sr/Ca ratios, encompassing low values (Sr/Ca≤3) indicative of freshwater
environments, intermediate values (3<Sr/Ca≤7) corresponding to estuarine brackish waters, and high values (Sr/Ca>7) reflect-
ive of marine habitats. All otolith core regions exhibited Sr/Ca values below 3 (1.78~2.61), indicating that spawning and hatch-
ing occurred in freshwater. While all individuals exhibited an overall anadromous pattern, variations in individual migratory tra-
jectories were evident, including the presence of a distinct population that overwinters in freshwater. Otolith Sr mapping results
were consistent with those obtained from quantitative line transect analyses. Based on early freshwater life-history characterist-
ics, individuals were categorized into two types: the short freshwater early life history type (Type SF) and the long freshwater
early life history type (Type LF). Further analysis of Sr/Ca variation suggested the potential existence of three ecologically dis-
tinct population groups within the estuary. One-Way ANOVA of the freshwater coefficient (F C ) between Type SF and Type LF
revealed significant differences, indicating divergent degrees of freshwater reliance during early life stages. These findings sug-
gest that the complex and variable environmental conditions of the Oujiang River Estuary have shaped unique migratory beha-
viors and habitat selection patterns in C. nasus, demonstrating the species' adaptive responses to local environmental heterogen-
eity. This study, through otolith microchemical analysis, not only provides a detailed reconstruction of the habitat use history of
C. nasus in the Oujiang River Estuary but also offers a scientific foundation for understanding its ecological traits and inform-
ing effective conservation and management strategies.
Key words: Coilia nasus; habitat use history; otolith microchemistry; Oujiang River Estuary

Corresponding author: JIANG Rijin. E-mail: jiangridge@zjou.edu.cn
Funding projects: National Key R & D Program of China (2024YFD2400404, 2020-YFD-0900805); Special Fund for the
Fishery Resources Survey Project of the Department of Marine Economy and Fisheries of Zhejiang Province (HYS-CZ-
202505, HYS-CZ-202408, HYS-CZ-202502)

中国水产学会主办 sponsored by China Society of Fisheries https://www.china-fishery.cn
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