曾萬年2006-07-262018-07-062006-07-262018-07-062004-07-31http://ntur.lib.ntu.edu.tw//handle/246246/20567為了瞭解台灣河口域烏魚 (Mugil cephalus Linnaeus 1758) 的生活史、入添動 態、及其洄游環境史，首先驗證耳石鍶鈣 (Sr/Ca) 比與鹽度的關係，然後解析河 口域的稚魚及不同棲地的成魚之耳石微細構造及其Sr/Ca 比。 由實驗室飼養的稚魚耳石Sr/Ca 比，與鹽度關係的實驗中發現，水體Ca 與 Sr 的含量，隨著鹽度 (0-35‰) 呈直線性增加；但Sr/Ca 比在0‰淡水中平均為 7.9±0.4×10-3，5‰海水中為15.1±0.6×10-3，其間增加約2 倍，在5-35‰海水中平 均值無差異 (14.0±0.8×10-3)。耳石Ca 含量，不受鹽度 (0-35‰) 的影響，平均值 為38.6±0.4%；但耳石Sr 含量及Sr/Ca 比，與水體Sr/Ca 比的變化一致，在0‰ 淡水 (Sr 0.1±0.01%、Sr/Ca 比3.2±0.4×10-3) ，及5-35‰海水中 (Sr 0.2±0.03%、 Sr/Ca 比6.4±0.7×10-3)，也相差約2 倍。此外，5-35‰海水中的耳石Sr/Ca 比， 與成長率呈負相關。這表示烏魚耳石的Sr/Ca 比，與鹽度及成長率的變化有 關，可用來重建烏魚在淡水及海水間的洄游環境歷史。To understand the life history, estuarine recruitment dynamics, and migratory environmental history of the grey mullet Mugil cephalus in the coastal waters of Taiwan, I examined the relationship between Sr/Ca ratios and ambient salinity, and analysed otolith microstructures and Sr/Ca ratios in juveniles sampled in estuaries and in adults from various habitats. A validation experiment indicated that the relationship between Sr/Ca ratios in otoliths of juvenile mullet and ambient salinity was non-linearly related. Ca and Sr contents in the rearing water increased linearly with salinities from 0-35‰. Sr/Ca ratios in the rearing water was non-linearly related to salinity; ratios increased approximately 2 fold from 7.9±0.4×10-3 in 0‰ freshwater to 15.1±0.6×10-3 in 5‰ seawater and remained constant of 14.0±0.8×10-3 in salinities from 5-35‰. In contrast, Ca content in the new increment of otoliths deposited during the 30 day rearing period did not change with salinities ranging from 0 to 35‰, averaging 38.6±0.4%. Sr content and Sr/Ca ratios in the otoliths increased approximately 2-fold from 0.1±0.01% (Sr) and 3.2±0.4×10-3 (Sr/Ca) in 0‰ freshwater to 0.2±0.03% (Sr) and 6.4±0.7×10-3 (Sr/Ca) in 5-35‰ seawater, which was consistent with the change in Sr/Ca ratios of the rearing water. In addition, Sr/Ca ratios in otoliths of fish reared in 5-35‰ seawater were negatively correlated with the otolith growth rate. These results indicate that Sr/Ca ratios in the otoliths were interactively affected by salinity and fish growth rate, which can be used to reconstruct environmental history of the mullet by differentiating fish migration between freshwater and seawater.application/pdf231037 bytesapplication/pdfzh-TW國立臺灣大學漁業科學研究所烏魚耳石鍶鈣比入添動態洄游環境史Grey mulletMugil cephalusOtolithStrontiumCalcium ratioRecruitment dynamicMigratory environmental historyjournal articlehttp://ntur.lib.ntu.edu.tw/bitstream/246246/20567/1/922611M002019.pdf