| Summary: | 碩士 === 國立臺灣海洋大學 === 水產養殖學系 === 100 === Two experiments were conducted to investigate the application of Yucca schidigera pure extract (YUPE) and clove oil on live-fish transportation of guppy (Poecilia reticulata) and juvenile white shrimp (Litopenaeus vannamei).
Experiment I aimed at using YUPE to reduce ammonia accumulation during guppy (0.24±0.01g) and white shrimp (0.99±0.01g) live-fish transportation. Four levels of YUPE (0, 18, 36 and 72 μl L-1) were added in shipping bag containing different densities of guppy (30, 45 and 60 L-1) and white shrimp (30, 50 and 75 L-1). Water in bags was sampled at 0, 3, 6, 9, 12 and 24 h for the analysis of pH, dissolved oxygen (DO), total ammonia nitrogen (TAN), nitrate nitrogen (NO3─-N), nitrite nitrogen (NO2─-N), total nitrogen (TN) and ammonia production rate (APR). The results showed that pH decrease with time and density. When YUPE concentration increased, TAN and APR reduced but NO2─-N increased. YUPE reacted with NO3─-N differently in freshwater (guppy) and seawater (white shrimp) and with packing density. When 72 μl L-1 YUPE was added, TAN reduced 75.4% in the 30 guppy L-1, but only reduced 57.9% in 60 fish L-1. When at 30 shrimp L-1, TAN decreased by 84.3%, but reduced only 41.1% at 75 L-1. For guppy, NO3─-N and NO2─-N accumulated and increased NO3─-N and NO2─-N, respectively. For shrimp, NO2─-N increased highly by 1465.7%, but NO3─-N reduced 46.4%. APR reduced from 0.018 mg to 0.004 mg L-1 g-1 shrimp h-1, and from 0.001 to 0.005 mg L-1 g-1 shrimp h-1.
Experiment II assessed the anesthesia effects of clove oil on guppy and white shrimp and the water quality in shipping bags. Three trials were conducted. Trial I was to find out the optimal concentration of short-term anesthesia by adding various concentrations of clove oil (10, 20, 25, 30, 50, 70, 100 and 200 μl L-1) and then observing the induction and recovery time when the fourth anesthetic phase reached. Trial II was to investigate the optimal concentration of long-term anesthesia (for live-fish transportation) by adding various concentration of clove oil (0, 10, 20, 30, 50 and 70 μl L-1) and then observing the induction and recovery time when the third anesthetic phase reached. Trial III simulated the live-fish transportation and studied the effect on water quality by adding various concentrations of clove oil (0, 10, 15 and 20 μl L-1) in the bag, and then monitoring pH, DO, TAN, NO3─-N, NO2─-N and TN after 24 h. The results showed that the optimal concentrations for short-term anesthesia were 70 μl L-1 to 100 μl L-1 and 70 μl L-1 for guppy and white shrimp, respectively. When anesthetizing for live-fish transportation, adding 10 μl L-1 to 20 μl L-1 clove oil could make guppy and white shrimp sedation, respectively. While in sedation the oxygen consumption reduced 18%, but TAN increased with clove oil concentration. When 20 μl L-1 clove oil was added, TAN increased about 5% than the control, but the other water parameters were not affected.
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