Tracking continental habitat shifts of eels using otolith Sr/Ca ratios: validation and application to the coastal, estuarine and riverine eels of the Gironde-Garonne-Dordogne watershed
Tracking continental habitat shifts of eels using otolith Sr/Ca ratios: validation and application to the coastal, estuarine and riverine eels of the Gironde-Garonne-Dordogne watershed
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DOI：
10.1071/mf04175
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发表时间：
2005-01-01
影响因子：
1.8
通讯作者：
Elie, P
中科院分区：
文献类型：
--
作者：
Daverat, F;Tomas, J;Elie, P
为了使相关的解释耳石锶：钙（Sr/Ca）的变化，鳗鱼的栖息地的转变，Sr/Ca的盐度关系在鳗鱼耳石进行了验证。在实验室中，通过每2个月在充满来自多尔多涅河的水的水族箱之间转移一组鱼，再现了幼鳗的下游和上游迁移（盐度= 0），上吉伦特河口（盐度= 5），下吉伦特河口（盐度= 25）和海岸（盐度= 30），代表了在吉伦特-加龙-多尔多涅流域观测到的盐度梯度。耳石Sr/Ca的个体发育变化进行了评估，在两组控制鱼保持在两个恒定的盐度（淡水或海水）之一。用X射线电子探针（WDS）对耳石中Sr/Ca比值的分析表明，水族箱的变化表现为Sr/Ca增加（向下游迁移）或Sr/Ca减少（向上游迁移）。没有个体发育的影响，检测到在玻璃鳗鱼标志以外的两组鱼的对照鱼的耳石。电子探针（WDS）分析的Sr/Ca的生活（横切在几个耳石的鳗鱼在吉伦特-加龙-多尔多涅流域）表明，他们中的一些移民鳗鱼经历了一个重大的栖息地转变，在他们的大陆生活。
To enable a relevant interpretation of otolith strontium : calcium (Sr/Ca) variations in terms of habitat shifts of eels, the Sr/Ca-salinity relationship in eel otoliths was validated. Downstream and upstream migrations of young eels were reproduced in the laboratory by transferring groups of fish every 2 months between aquaria filled with water coming from the Dordogne river (salinity = 0), the upper Gironde estuary (salinity = 5), the lower Gironde estuary (salinity = 25) and the coast (salinity = 30), which represented the salinity gradient observed in the Gironde-Garonne-Dordogne watershed. Ontogenetic changes in otolith Sr/Ca were assessed in two groups of control fish that were kept in one of either two constant salinities (fresh water or seawater). X-ray electron microprobe (wavelength dispersive spectrometry, WDS) analyses of Sr/Ca ratios in the otoliths showed that the change of aquarium was recorded as a Sr/Ca increase (downstream migration) or a Sr/Ca decrease (upstream migration). No ontogenetic effect was detected in otoliths of control fish outside glass eel marks in either group of fish. The electron microprobe (WDS) analysis of the Sr/Ca life (transected in several otoliths of eels caught in the Gironde-Garonne-Dordogne watershed) showed that some of them were migrant eels that had experienced one major habitat shift during their continental life.