长江、赣江鲢幼鱼耳石核区元素指纹特征分析及其在群体识别中的应用研究

Analysis on the Otolith Core Elemental Fingerprint of Young-of-the-year(YOY) Silver Carp from Yangtze River and Ganjiang River and Its Application in Stock Identification

采用激光剥蚀电感耦合等离子质谱分析技术(LA-ICP-MS)对2012、2014及2016年采自长江、赣江的鲢幼鱼耳石核区微量元素(Sr、Ba、Mg、Na、Si、Cr、Mn、Ca、Zn)进行了测定分析。结果显示:长江、赣江鲢幼鱼耳石核区4种微量元素与钙元素的比值(Sr∶Ca、Ba∶Ca、Si∶Ca、Mg∶Ca)在同一水体年际间基本不变,但不同水体(长江、赣江)鲢幼鱼群体间存在显著性差异,其中,Si∶Ca和Sr∶Ca比值对群体识别的贡献率最大。应用这4种元素比值的线性判别分析(LDFA)对长江鲢幼鱼群体整体判别成功率为92. 11%,其中对2012年、2014年、2016年样本的判别成功率分别为:92. 31%、93. 33%、90. 91%;对赣江鲢幼鱼群体整体判别成功率为92. 31%,其中对2012、2014、2016年样本的判别成功率分别为:80. 00%、96. 77%、93. 75%。研究表明,这4种元素比值可以作为识别长江和赣江鲢群体的环境元素指纹,LA-ICP-MS耳石元素指纹分析技术用于识别长江、赣江鲢群体确实有效可行。

In the current study,the nine elements in the otolith core elements( Sr,Ba,Mg,Na,Si,Cr,Mn,Ca,Zn) of young-of-the-year( YOY) silver carp collected during August-September of 2012,2014,and 2016 from the Yangtze River and Ganjiang River were analyzed using laser ablation inductively coupled plasma mass spectrometry( LA-ICP-MS). It was showed that the ratios of the four trace elements to the calcium( Sr ∶ Ca,Ba ∶ Ca,Si ∶ Ca,Mg ∶ Ca) in the otolith core of the YOY silver carp in Yangtze River and Ganjiang River was basically unchanged among the three years from the same river. However,there was a significant difference between the two stocks from Yangtze River and Ganjiang River and the ratios of Si ∶ Ca and Sr ∶ Ca made the greatest contribution to stock identification. According to the linear discriminant analysis( LDFA) of the four element ratios,the overall classification accuracy rate of Yangtze River silver carp stock was 92. 11%,and the classification accuracy rates in 2012,2014 and 2016 were 92. 31%,93. 33% and 90. 91%,respectively. The overall classification accuracy rate of Ganjiang River silver carp stock was 92. 31% and the classification accuracy rates in 2012,2014 and 2016 were 80. 00%,96. 77% and 93. 75%,respectively. Thus,the four element ratios in otolith core could be used as elemental fingerprints to identify silver carp stocks from the Yangtze River and Ganjiang River. Analysis of otolith microchemistry by LA-ICP-MS will be an effective technique in stock discrimination such as silver carp from Yangtze River and Ganjiang River.