机构地区:[1]Wuxi Fisheries College,Nanjing Agricultural University,Wuxi,214081,China [2]Key Laboratory of Fishery Ecological Environment Assessment and Resource Conservation in Middle and Lower Reaches of the Yangtze River,Freshwater Fisheries Research Center,Chinese Academy of Fishery Sciences,Wuxi,214081,China
出 处:《Acta Oceanologica Sinica》2023年第1期120-130,共11页海洋学报(英文版)
基 金:The National Natural Science Foundation of China under contract No.31602159;the Agricultural Finance Special Project under contract No.CJDC-2017-22;the Scientific Research Foundation of Wuxi City for Returned Oversea Chinese Scholars under contract No.CZ2019231400.
摘 要:The estuarine tapertail anchovy(Coilia nasus)is a high-value commercial fish.Estimating the spawning site or hatchery origin and habitat is essential for its conservation.This study aimed to determine the habitat use and life history characteristics of C.nasus from the Changjiang River Estuary.We investigated the environmental signatures of strontium(Sr)and calcium(Ca)in the otoliths of the collected specimens using electron probe microanalysis;additionally,we examined their gonadal maturity stage.Our results indicate that the 31 adult C.nasus specimens used in this study could be classified into two types based on their otolith Sr:Ca concentration ratios and their gonadal maturity stage.The long freshwater early life history type(Type LF)had wider central region in the otolith with low Sr:Ca concentration ratios ranging from 1.24±0.62 to 1.92±0.78 and a bluish pattern of low Sr content level.These fish are of riverine origin and had a relatively long early life history in freshwater and low gonadal maturation when captured.The short freshwater early life history type(Type SF)had a shorter central region in the otolith with low Sr:Ca concentration ratios ranging from 1.35±0.5 to 2.82±0.97 and a correspondingly bluish pattern.These fish also had a relatively short-term early life history in freshwater and high gonadal maturation when captured.The results of the otolith microchemical analysis indicated that Type LF and Type SF originated in spawning/hatching sites far from and close to the estuary,respectively.The mature gonads of Type SF fish indicated that they may breed in areas close to the estuary,whereas the immature gonads of Type LF fish indicated that they may breed in areas far from the estuary.This study is the first to reveal that the Changjiang River Estuary contains stocks of anadromous C.nasus originating in different spawning sites during the same season.The estuarine habitat plays a critical role in the connectivity between freshwater recruitment and the marine resources available to adult spaw
关 键 词:Coilia nasus OTOLITH migration connectivity spawning site
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