農業部-水產試驗所全球資訊網農業部-水產試驗所全球資訊網

本試驗旨在探討鱸鰻苗的半致死溫度、適宜的攝餌溫度，以及溫度與餌料對成長率與活存率的影響，以期建立鱸鰻苗培育技術。本試驗在 25 °C 水溫蓄養1天後，以每 1 °C/hr 水溫之速度持續升或降溫，進行鱸鰻苗對高、低溫耐性能力觀察，當水溫升至 36.6 °C 開始有死亡產生，而至 38.2 °C 則全部死亡，當降至 8.3 °C 時即開始有死亡現象，6.8 °C 即全部死亡，其最高與最低半致死溫度分別為 37.1 及 7.6 °C。而鱸鰻苗經由 25 °C 水溫蓄養1天後，每天升或降飼育水溫 1 °C，顯示在 29.2 °C 時其攝餌量達到最高，超過 30.2 °C 後，攝餌量隨水溫增高而下降，34.2 °C 時明顯減少，37.0 °C 時完全不攝餌，其最高攝餌溫度約在 36.0 ~ 37.0 °C。在15、20、25 及30 °C 水溫中，經 6 週飼育後，成長率以水溫 30 °C 組的 713.3% 最高，與2 5 °C 組的 573.3% 無顯著差異，但明顯高於 20 及 15 °C 組。飼料轉換率以 25 °C 組較佳，其次是30、20 及 15 °C 組。投餵四種餌料，經飼育 30 天後，成長率以活絲蚯蚓組的 820.2% 最高，明顯高於膏狀飼料、冷凍絲蚯蚓與鰻魚配合飼料混合、鰻魚配合飼料組。熱帶性鱸鰻苗培育，可採用室內小系統，控制水溫在 25 ~ 30 °C，其育成率可高於傳統室外池；而以膏狀飼料飼養已可完全取代初期使用活絲蚯蚓的馴餌方式。

In this study, experiments were conducted to investigate the half lethal temperature, suitable feeding temperature, and effects of different temperatures and diets on the growth of swamp eel (Anguilla marmorata) elvers.
Swamp eel elvers were reared for one day at 25 °C, then cultivated further as the water temperature was increased or decreased continuously at the rate of 1 ℃ per hour. As the water temperature rose to 36.6 °C, the elvers started to die, and when it had reached 38.2 °C, all the elvers had died. When the water temperature declined to 8.3 °C, a few elvers died, while all the rest had died by the time it reached 6.8 °C. The upper and lower lethal temperatures were estimated to be 37.1 °C and 7.6 °C, respectively.
In another experiment, after elvers were stocked at 25 °C for one day, the water temperature was increased or decreased for 1 °C per day. The elvers had the highest feeding rate at 29.2 °C. At over 30.2 °C, their feeding rate slowed down, and at 37.0 °C, it had completely stopped.
In the growth trial, 300 swamp eel elvers were reared in four thermo-regulated recirculating tanks at 15, 20, 25, and 30 °C for 6 weeks. The elvers reared at 30 °C had the best growth rate (713.3%). That growth rate was not significantly different from that of the elvers reared at 25 °C, but it was significantly higher than the rates for those reared at 20 °C and 15 °C. The feed conversion ratio of the elvers reared at 25 °C was better than those of the elvers reared at 30, 20, and 15 °C.
A 30-day experiment was also conducted on four kinds of diets for swamp eels. The group cultivated with a living wiggler diet attained the highest percent weight gain (820.2%), which was significantly higher than those of the groups reared, respectively, with paste feed, a frozen wiggler mixed eel diet, and an eel diet.
In conclusion, tropical swamp eel elvers can be cultivated successfully indoors when reared in controlled water temperatures in the range of 25~30 °C and fed with paste feed.