Endocrine Effect on The Osmoregulation in The Protandrous Black Porgy, Acanthopagrus schlegeli

• Main Author: 汪懷遠
• Other Authors: Chang Ching-Fong
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/00511754440134329258

碩士 === 國立海洋大學 === 水產養殖學系 === 90 === Abstract The objectives of the study were to investigate the effects of salinity and hormones in osmolality, Na+/K+-ATPase activity in gill, intestine and kidney in black porgy. Serum osmolality was increased in black porgy adapted from freshwater to seawater environment. Na+/K+-ATPase activity in gill and kidney decreased with the increase of salinity. Na+/K+-ATPase activity in intestine increased in fish adapted to seawater. Serum cortisol levels were higher in freshwater than those in seawater fish. Serum osmolality reached to the highest value after 8-h acute exposure from freshwater to seawater. Na+/K+-ATPase activity in gill and kidney was increased but Na+/K+-ATPase activity was decreased in the period of the first 4-h exposure from freshwater to seawater. Cortisol and aldosterone but not thyronine（T3）stimulated serum osmolality in freshwater fish. Cortisol, T3 and aldorsterone decreased Na+/K+-ATPase activity in gill and intestine of freshwater black porgy. Cortisol, T3 and aldorsterone decreased serum growth hormone（GH）reach but not Insulin-like growth factor（IGF-I） in freshwater fish. Cortisol, T3 and aldosterone did not had significant and consistent effects in the serum osmolality, Na+/K+-ATPase activity in gill and kidney, Serum GH level and IGF-I levels in seawater fish. Serum IGF-I and GH levels were decreased in black porgy adapted from seawater to freshwater . Higher cortisol and lower gonadotropin II levels in serum were found in the freshwater fish than those in seawater fish. The data indicated that cortisol , aldosterone, GH and IGF-I were closely associated with the changes of the osmoregulation in euryhaline black porgy.