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

白蝦的稚蝦 (平均體重分別為0.33±0.11公克及0.15±0.09公克) 曝露在不同濃度的氨及亞硝酸中，以決定彼等對白蝦的稚蝦其24、48、72及96小時的半致死濃度（Median lethal concentration, LC50）。非離子化氨-氮對白蝦的稚蝦之24、48、72及96小時的LC50 分別為3.70、2.27、1.83及1.65 mg/l (水溫27℃、鹽度21?、pH值7.9-8.3)，而總氨-氮則分別為71.51、43.79、35.30及31.80 mg/l。亞硝酸-氮對白蝦的稚蝦之24、48、72及96小時的LC50 分別為164.2、47.9、32.5及23.9 mg/l (水溫、鹽度和pH值分別為27℃、21?、7.9-8.3)。

Two groups of juvenile white shrimp Litopenaeus vannamei with average body weight of 0.33 ± 0.11g and 0.15 ± 0.09g were exposed to different concentrations of ammonia and nitrite to determine the median lethal concentration (LC50) by a static renewal method. The corresponding 24, 48, 72 and 96 h LC50 of ammonia were 3.70, 2.27, 1.83 and 1.65 mg/l for NH3-N (un-ionized ammonia as nitrogen) and 71.51, 43.79, 35.30 and 31.80 mg/l for ammonia-N (un-ionized plus ionized ammonia as nitrogen), in 21? seawater at pH 7.9-8.3 and at 27℃. The 24, 48, 72 and 96 h LC50 of nitrite-N were 164.2, 47.9, 32.5 and 23.9 mg/l, respectively, in 21? seawater at pH 7.9-8.3 and at 27℃. The safe values of NH3-N, ammonia-N and nitrite-N for white shrimp were 0.17, 3.18 and 2.4 mg/l, respectively.
Key words：Ammonia, Nitrite, White shrimp Litopenaeus vannamei, Acute toxicity