探討在循環水系統中海鱺 (Rachycentron canadum) 仔魚的成長及活存率之影響因子

Factors Affecting the Growth and Survival Rate of Cobia (Rachycentron canadum) Larvae in a Recirculating System

莫瑞修(Javier Mauricio García Rodríguez)

指導教授 ： 李彥宏 ； 葉信平

國立屏東科技大學/農學院/熱帶農業暨國際合作系所/碩士(2009年)

https://doi.org/10.6346/NPUST.2009.00315

摘要

海鱺 (Rachycentron canadum) 生長速率快，活存率高且肉質鮮美，所以成為現今海水水產養殖業熱門飼養魚種。在近幾年，許多國家已針對海鱺魚苗的大量生產進行研究，但是穩定地飼養健康的海鱺魚苗至可放養到箱網之大小，仍然是現今一大挑戰。本實驗以循環水系統分別做四種不同處理，來探討影響魚苗生長及活存率之因子。1.(T1)以橈足類(copepods， Apocyclops royi)代替豐年蝦幼生(Artemia nauplii)來飼養海鱺魚苗並進行比較；2.(T2)在魚苗培育槽加入微藻 (Isochrysis galbana or Nannochloropsis oculata) ；3.(T3)以濃度0.250 mg l-1的二氧化氯(ClO2)對輪蟲分別做1、5及10分鐘等不同處理，再飼養魚苗。4.瞭解培育槽顏色對魚苗生長及活存率之影響。本實驗也對活體餌料(live preys)做脂肪酸之分析。結果，餵食橈腳類的魚苗明顯較豐年蝦幼生好，魚苗體長為14.40±0.035mm，活存率為 (8.32 ± 0.32%) 。添加I. galbana於培育槽中，對於孵化後10天內之海鱺魚苗表現有正面的影響。使用二氧化氯可明顯降低輪蟲75.0%細菌的含量且不影響輪蟲存活，但會影響海鱺魚苗生長及存活率。最後，底色為棕色之培育槽有最快的生長率 (16.1 ± 0.49 mm)，而灰色及紅色則有較高的活存率。

關鍵字

海鱺幼苗 ； 存活 率 ； 成長 ； 孵化桶顏色 ； 綠藻水培育 ； 活體餌料

並列摘要

This study consisted of four trials that aimed to improve factors affecting the growth and survival in early stages in the larval rearing of cobia (Rachycentron canadum) under a recirculating system. The initial trial (T1) of this study was conducted to examine the use of copepods, Apocyclops royi, as live prey for cobia larvae and compare the performance of copepod as live prey with that of the traditional live prey, Artemia nauplii. Subsequently in a second trial (T2), we evaluated the effects of adding live microalgae (Isochrysis galbana or Nannochloropsis oculata) to the larval rearing tanks. The use of rotifers desinfected with chlorine dioxide (ClO2) at concentration of 0.250 mg l-1 for 1, 5 and 10 min prior to feeding to the larvae was evaluated in trial 3 (T3). A final trial (T4) was designed to evaluate the influence of tank wall color on the growth and survival of cobia larvae. Fatty acid profile of live preys used throughout this study was analyzed. At the end of T1, means of standard length (14.40 ± 0.035mm) and survival rates (8.32 ± 0.32%) of larvae fed with copepods were significantly improved. Adding I. galbana to rearing tanks had positive effects on the larval performance of cobia larvae on the first 10 days post-hatch (dph). The use of ClO2 was effective in reducing up to 75.0% bacteria associated with rotifers. However, feeding cobia larvae with ClO2-disinfected live prey had negative impact on the growth and survival. In T4, brown tank wall color had the fastest mean growth (16.1 ± 0.49 mm) but the greatest survival rates were achieved in tanks with gray and red wall colors. Results of these trials present evidence that factors such as type of live feed, larval culture systems and rearing techniques influence in the performance of cobia larvae in terms of growth and survival rates.

並列關鍵字

cobia larvae ； growth and survival rate ； tank wall color ； greenwater culture ； live prey

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