碩士 / 國立中山大學 / 海洋生物科技暨資源學系研究所 / 106 / White shrimp (Litopenaeus vannamei) was introduced to Taiwan in 1994 and immediately became a popular farming species after the market crash of tiger shrimp (Penaeus monodon). White shrimp is popular for the following reasons: (1) High growth rate. It takes only 3 - 4 months of cultivation before selling in the market. (2) Low cost of water. Water is the second highest cost in aquaculture. Because white shrimp is euryhaline, it can adapt to a wide range of salinities from 1 - 2 ‰ hypotonic to 40 ‰ hypertonic. Aquaculturists take advantage of this feature and desalinate seedlings, if their aquatic farms are far away from the source of seawater. Aquaculture of white shrimp in Taiwan is practiced in a wide range of salinities. In Mexico and India, the evaporation rate is very high, so the salinity of farming environment often exceeds the value of normal seawater. Environment, pathogen and host are the three main aspects in aquaculture. Although white shrimp can adapt to a wide range of salinities, the osmotic pressure of white shrimp is 718 mOsm/kg, which is equivalent to the salinity of 25 ‰. An extreme salinity environment may bring physiological stress and affect their immunity. In this study, we cultivated white shrimp in different salinity environment (2.5‰, 5‰, 15‰, 35‰ and 45‰) for two weeks and observe their innate immune responses. We estimated the total hemocyte count (THC), expression pattern of gene in prophenoloxidase activation system (proPO system): prophenoloxidase 1 (proPO1), prophenoloxidase 2 (proPO2), prophenoloxidase activating factor (PPAF), serine proteinase (SP), and activity level of phenoloxidase activity (PO activity). Our results showed that in the salinity of 15 ‰, PO activity and THC were significantly higher than in 2.5 ‰ and 5 ‰. However, the expression level of SP was significantly higher in 35‰. We suggested that more energy is required to adjust osmotic pressure in hypotonic environment, therefore organisms have insufficient to maintain immunity. The ultimate good of this study is to provide guidelines for white shrimp aquaculturists while choosing salinity environment for better immunity and higher harvest rate.
| Identifer | oai:union.ndltd.org:TW/106NSYS5277006 |
| Date | January 2018 |
| Creators | Chun-Ping Liang, 梁鈞評 |
| Contributors | Cheng-Hao Tang, Hsiu-Chin Lin, 湯政豪, 林秀瑾 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 47 |
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