| Summary: | 碩士 === 國立海洋大學 === 水產養殖學系 === 89 === Kuruma shrimp Marsupenaeus japonicus following exposure to different concentrations of ambient ammonia-N at 0.01, 0.55, 1.16, 4.89,10.16 and 21.90 mg/l at 30 ppt seawater and 22℃ after 1, 2, 6, 12 and 24 h. Hemolymph ammonia-N and urea-N increased directly with ambient ammonia-N and exposure time with significant difference (p < 0.05) among treatments. Hemolymph cortisol and hemolymph glucose increased directly with ambient ammonia-N and reached the highest concentration after 6 h exposure. M. japonicus following 6 h exposure to 21.90 mg/l ammonia-N increased its hemolymph GPT and hemolymph GOT to the highest, and was 56.483 U/L and 152.683 U/L, respectively. M. japonicus following 2 h exposure to ambient ammonia-N increased significantly its hemolymph lactate, but decreased after 24 h. Hemolymph LDH activity of M. japonicus increased directly with ambient ammonia-N, and reached the highest after 1 h exposure.
M. japonicus following exposure to different concentrations of ambient nitrite-N at 0.01, 0.98, 5.13, 9.86, 20.12 and 31.06 mg/l at 30 ppt seawater and 22℃ after 1, 2, 6, 12 and 24 h. Hemolymph ammonia-N was inversely related to ambient nitrite-N and exposure time. M. japonicus following 1 h exposure to 20.12 and 31.06 mg/l nitrite-N increased its cortisol, glucose, lactate and activities of LDH, GPT and GOT to the highest. M. japonicus following 2 h exposure to 5.13 and 9.86 mg/l, nitrite-N increased its cortisol, glucose, lactate and the activities of LDH, GPT and GOT to the highest.
The present study documented that M. japonicus following 1 h exposure to ambient ammonia-N as low as 1.16 mg/l or 1 h exposure to ambient nitrite-N as low as 5.13 mg/l caused significant increases of cortisol and glucose. They are considered as indicators for the primary effect of stress response. Monitoring of hemolymph cortisol and glucose levels of cultured shrimp are of beneficial for the management in shrimp farming.
|
|---|
