黄海南部野生银鲳和鮸鱼的耳石元素微化学研究

Investigation on otolith microchemistry of wild Pampus argenteus and Miichthys miiuyin the southern Yellow Sea,China

利用电子显微探针元素分析技术(EPMA)对黄海南部野生银鲳和鮸鱼的耳石进行了锶和钙沉积特征的初步分析。定量线分析结果表明,两种鱼类耳石的Sr/Ca之间存在显著的种间差异。银鲳耳石Sr/Ca比,在耳石核心及相邻处为低值区(5.86±0.92);3段Sr/Ca高值区分别为近核心部(7.88±1.28)、第1龄处(9.44±1.82)及耳石边缘(7.91±1.38);揭示银鲳孵化和早期发育应需要盐度适中的生境,当龄鱼在后期的生长中需洄游经过两段高盐生境(其中之一在第1龄时)。鮸鱼耳石Sr/Ca比波动表现为耳石核心处(7.72±0.97)高于其余部分,反映了鮸鱼孵化及初期发育阶段可能生活在高盐度生境,而当龄鱼随后阶段的生长和发育过程则会洄游至盐度有所降低的生境中进行。

An electron probe microanalyzer（EPMA）was used to analyze the profile of otolith Sr and Ca microchemistry of wild Pampus argenteus and Miichthys miiuyin the Southern Yellow Sea,China.Results of line transect analysis clearly indicated that inter-species differences in the otolith Sr∶Ca concentration ratios were remarkable.In P.argenteus,the otolith core showed low Sr/Ca ratios（5.86±0.92）,while the areas around core,1-year ring and edge of otolith presented the high Sr/Ca ratios[（7.88±1.28）,（9.44±1.82）and（7.91±1.38）,respectively].A moderate salinity habitat seemed to be necessary for the hatching and early ontogenetic development of P.argenteus.However,in development stages of YOY（young of the year）,P.argenteus may need two phases of high salinity habitats,one of which was at age 1year.For the M.miiuy,Sr/Ca ratios（7.72±0.97）in otolith core were higher than those in the remaining areas.The high salinity habitat seemed to be required at the stages of hatching and post-hatching development of M.miiuy,while reduced salinity habitat might be preferable for the development and growth at the remaining stages of the YOY life history.