| 摘要: |
| 利用X-射线电子探针微区技术（electron probe microanalysis，EPMA），对长江口不同水域中捕获的焦氏舌鳎、皮氏叫姑鱼、鮸鱼和光泽黄颡鱼耳石中的Sr含量进行耳石微化学研究，结果发现，焦氏舌鳎是典型的海水鱼类，不仅Sr：Ca比（按惯例标准化为Sr：Ca×103）的移动平均值高（>7），而且Sr含量面分析图亦呈现为对应高盐度海水的黄色或红色图谱。虽然皮氏叫姑鱼和鮸鱼从出生直至被捕Sr：Ca比的移动平均值都在3—7间波动，总体上属河口半咸水栖息鱼类，但从Sr含量面分析图来看，皮氏叫姑鱼生活史履历更为复杂，可包括淡水（对应蓝色图谱）和半咸水生境（对应绿色图谱）；而鮸鱼仅在长江口较高盐度半咸水或海水生境中活动，未见进入过淡水的履历。光泽黄颡鱼表现出仅利用淡水生境的履历，其Sr：Ca比的移动平均值仅在1.5—3间窄幅波动，整个生活史均在淡水区域里活动，表现为长江口典型的淡水栖息鱼类。本研究从新的角度提供了较为客观、直观和最新的信息，用以较为准确地重建和掌握长江口这些不同鱼类的生境利用特征。 |
| 关键词: 耳石 微化学 焦氏舌鳎 皮氏叫姑鱼 鮸鱼 光泽黄颡鱼 长江口 |
| DOI：10.11693/hyhz20180300069 |
| 分类号:S931;Q959.4 |
| 基金项目:农业财政专项“长江渔业资源与环境调查-长江下游渔业资源与环境调查”，CJDC-2017-22号；中央级公益性科研院所（中国水产科学研究院级）基本科研业务费专项资金项目“基于我国经济鲚属的鱼类耳石微化学研究”，2016PT01号。 |
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| OTOLITH MICROCHEMISTRY OF FOUR FISH SPECIES FROM THE CHANGJIANG RIVER ESTUARY, CHINA |
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LIU Hong-Bo1, JIANG Tao1, QIU Chen2, YANG Jian1
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1.Key Laboratory of Fishery Eco-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;2.Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China
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| Abstract: |
| An electron probe X-ray micro-analysis (EPMA) was performed to determine Sr and Ca accumulation in otolith of Cynoglossus joyneri, Johnius belengerii, Miichthys miiuy, and Pseudobagrus nitidus collected from different water areas in the Changjiang (Yangtze) River estuary, China. X-ray intensity mapping in the otoliths was analyzed in which the level of Sr content (positively related to salinity) is reflected in different colors. The results show that C. joyneri was a typical brackish and sea water resident fish species, the mean of Sr:Ca ratio (standardized to Sr:Ca×103) of the otolith was high (>7), displaying higher salinity patterns. J. belengerii and M. miiuy were estuarine residents as they had moderate Sr:Ca ratios (3-7), whereas J. belengerii seemed to live in different salinity habitats. Pseudobagrus nitidus lived in freshwater only and the average Sr:Ca ratio was low (1.5-3); this species could be used as a freshwater habitat indicator in the estuary. This study provides an objective and intuitive tool for discriminating the habitat patterns and migration history of the fish life in the estuary. |
| Key words: otolith microchemistry Cynoglossus joyneri Johnius belengeri Miichthys miiuy Pseudobagrus nitidus Changjiang River estuary |
