Approach the Reasons of Different Cd-Resistance Between Goldfish（Carassius auratus）and Common carp（Cyprinus carpio）

• Main Authors: Zhang Feng-Ming, 張峯銘
• Other Authors: Wu Su-Mei
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/03121684406837886492

碩士 === 國立嘉義大學 === 水生生物科學系研究所 === 101 === The present study found that 96 h-LC50 of Cd was 100 μM and 80.3 μM on goldfish and common carp, respectively. The objective of this study was to clarity what are the possible reasons of the Cd-resistance different between the goldfish (Carassius auratus) and the Common carp (Cyprinus carpio). Our results showed that: (1) MT contents of goldfish was 2.1 fold higher than the carp before Cd exposure, and the goldfish induced MT expression were 1.9, 4.4 and 1.0 fold higher than carp upon 44.6 μM Cd exposure for 1, 2 and 3 days, respectively. We suggested that the goldfish to induce MT expression by Cd was more efficiency than carp. (2) The amount of Cd accumulation in goldfish was higher than carp after 4 days of Cd exposure. (3) The calcium influx rate was no significant between goldfish and carp upon Cd treatment for 24-48 hours, and calcium content appears a similar inhibition by Cd for both studied fish. (4) Moreover, mucus cells of goldfish gill were 2.4 fold more than the control after 4 days of Cd treatment, while carp were increased 2.9 times compare the control after 3 days of Cd treatment. Observably, dramatical elevation of mucus cells will affect the respiratory rate on fish. (5) Epithelial thickness of gill on goldfish was increased 2.05 times than the time point of initiate after Cd treatment. We suggested that this phenomenon may be related with gas exchange on fish. On the other hand, it also may reduce Cd into the body from the gill filaments. (6) Goldfish showed around 36.9% of gills to appear hematoma after Cd treatment, however, the only 14.8% on carp after the same treatment condition. According to our findings, we suggested that the efficiency of MT expression higher increase on goldfish than on carp, which induced the goldfish to appear a higher Cd-tolerance than carp.