Physiological responses to ocean acidification in orange-spotted grouper (Epinephelus coioides)
| Autor: | Guo-Kai Hong, 洪國凱 |
|---|---|
| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 According to ocean acidification researches, the pH of seawater is about 8.1 nowadays. It is estimated the pH will decrease to 7.7 in 2100, and 7.4 in 2300. Thus it is important to investigate the physiological responses for prediction of the implications of ocean acidification on marine organisms. In this regard, a reef-associated species, orange-spotted grouper (Epinephelus coioides), was used to explore the influence of two levels (pH 7.7 and pH7.4) of ocean acidification on the physiological responses at various aspects, including stress response, acid-base regulation, and energy metabolism. In stress response, both the expression of heat shock protein 70 (HSP70) and plasma glucose levels elevated significantly in response to hypercapnia. It was suggested induction of stress responses could cope with the challenge of ocean acidification. By using acid-base regulation related proteins including Na+/K+-ATPase (NKA), H+-ATPases (VHA), and cytosolic carbonic anhydrase (CAc), in addition to plasma osmolality and blood acid-base parameter (pCO2, [HCO3-] and pH ), the results showed that NKA,VHA and CAc were up-regulated significantly in response to hypercapnia, but plasma osmolality and blood pH were unaffected. It was suggested that grouper will elevate protein expression and activity of NKA,VHA and CAc to perform acid-base regulation and maintained within a homeostatic range of plasma osmolality and blood pH. Furthermore, in energy metabolism of ocean acidification effect, the gill glycogen content, mRNA expression of pyruvate kinase (PK) and cytochrome c oxidase (COX) are up-regulated significantly in response to hypercapnia. It suggests that orange-spotted grouper (E. coioides) have to accumulate glycogen and produce energy in gill in order to against influence of ocean acidification. However, the liver glycogen contents and mRNA expression of muscle myosin and myostatin were not affected by ocean acidification. This integrative study investigated multiple physiological responses in a marine teleost to ocean acidification. Our study provided evidences that E. coioides consumed more energy to conduct stress response and acid-base regulatory mechanism to adapt and survive in increasingly serious ocean acidification. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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