本論文利用31天之養殖試驗來評估水溫對美洲大口鱸 Micropterus salmoides的成長、存活、攝餌量以及耐溫性的影響。 美洲大口鱸幼苗(4.17 ± 0.14 g) 36尾一組,分別飼養於27、30、33以及36 ℃四種水溫,用商業性鱸魚飼料(45%粗蛋白以及16 %脂肪)一天餵食2次直到飽食為止。每一水溫3重複。餵食31天後,飼養於27、30、33以及36 ℃之幼苗平均體重分別為23.3 ± 4.5 g、23.5 ± 4.3 g、18.9 ± 3.8 g以及11.6 ± 2.5 g,27及30 ℃兩組之平均體重明顯大於33及36 ℃兩組。體重的變異係數(coefficient of variation,CV)各處理組之間無顯著差異;幼苗日成長率(specific growth rate)分別為61.53 ± 1.39%、62.13 ± 0.28%、47.43 ± 1.29%以及24.25 ± 0.49%,27及30 ℃兩組之日成長率顯著大於33及36 ℃兩組。幼苗增重百分比(percentage weight gain)分別為452.03% ± 20.61、457% ± 16.56、352.5% ± 9.85 以及182.5% ± 10.84,前兩組之增重百分比顯著大於後兩組。日成長率和增重百分比在30 ℃以後隨飼養溫度升高而降低。 存活率(survival rate,%)在27、30、和33℃處理組均為100%,而在36 ℃處理組為30.55 ± 16.9 %,36 ℃處理組存活率明顯比其他處理組低。 攝餌量(Feed intake、%day-1)27、30、33和36 ℃處理組分別為3.19 ± 0.06%、3.21 ± 0.05%、3.10 ± 0.02%以及2.71 ± 0.07%,36 ℃處理組明顯比27 ℃、30℃以及33 ℃處理組低。 飼料轉換率(Feed conversion ratio)在27、30、33和36 ℃處理組分別為0.71 ± 0.01、0.71 ± 0.02、0.77± 0.01以及0.88 ± 0.01,27和30 ℃之間無顯著性差異(p>0.05),36 ℃處理組明顯比27 ℃、30℃以及33 ℃處理組低。 臨界溫度最大值(Critical thermal maxima,℃)在四種不同適應溫度分別為38.6 ± 0.2 ℃、40.5 ± 0.3 ℃、41.1 ±0.2以及41.7 ± 0.2 ℃,魚苗之臨界耐溫性溫度隨飼養溫度升高而有顯著增加之趨勢。 致死溫度(Leath temperature,℃)在四種不同適應溫度分別為39.3 ± 0.1 ℃、40.8 ± 0.2 ℃、41.5 ± 0.2 ℃以及42.1 ± 0.1 ℃,致死溫度隨飼養溫度升高而有顯著增加之趨勢。
This study aims to examine the effects of high temperature on the growth, survival, feed ingestion and thermal tolerance of Micropterus salmoides juvenile in glass fiber tank for 31 days.Feed-trained Micropterus salmoides fry (4.17 ± 0.14 g) were fed with a commercial bass diet (crude protein 45%、crude lipid 16 %)twice daily to satiation. Four treatments 27, 30, 33 and 36 ℃for triplicate. Micropterus salmoides juvenile at 27, 30, 33 and 36 ℃average weight after fed 31 days were 23.3 ± 4.5 g, 23.5 ± 4.3 g, 18.9 ± 3.8 g and 11.6 ± 2.5 g, respectively. Coefficient of variation of body weight were no significant difference.Specific growth rate(%.day-1)were 61.53±1.42%, 62.14 ± 0.27%, 47.45 ± 1.28% and 24.26 ± 0.49%, respectively Percentage weight gain were 452.03 % ±20.61 、457 % ±16.56 、352.5 % ±9.85 and 182.5 % ±10.21, respectively. Specific growth rate and Percentage weight gain significantly decrease with an increasing temperature after 30 ℃. At 27, 30, 33 and 36 ℃ treatments the survival rate (%)were all 100 % but at 36 ℃ treatment the survival were 30.55 ± 16.9 %. Survival rate of 36 ℃ treatment were significantly higher than that of the other temperatures. Feed intake(%/day)at four temperature acclimation were 3.19 ± 0.06 %, 3.21 ± 0.13%, 3.10 ± 0.02% and 2.71 ± 0.27%, respectively. Feed intake at 36 ℃ treatment were significantly lower than that at 27, 30 and 33 ℃ treatments. Feed convert ratio(g.g-1)at four different temperature acclimation were 0.71 ± 0.01、0.71 ± 0.02、0.77 ± 0.01 and 0.88 ±0.01, respectively. There were no significant difference among 27, 30 and 33 ℃ treatments but feed convert ratio at 36 ℃were significantly lower than that at the other temperatures. Critical thermal tolerance at four different temperature treatments were 38.6 ± 0.2 ℃, 40.5 ± 0.3 ℃, 41.1 ±0.2 ℃ and 41.7 ± 0.2 ℃, respectively. Critical thermal tolerance were significantly increased with i an ncreasing temperature. Lethal temperature at four different temperature acclimation were 39.3 ± 0.1 ℃、40.8 ± 0.2 ℃、41.5 ± 0.2 ℃ and 42.1 ± 0.1 ℃, respectively. Lethal temperature were significantly increased with anincreasing temperature.