Chronic ammonia toxicity and ammonia excretion in marine medaka Oryzias melastigma

• 作 者: NaGao[1]LimeiZhu[2]ZhiqiangGuo[2]LiZhang[3]
• 机 构: South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 Xingang Rd West, Guangzhou
• 出 处: 第五届全国海洋生态研讨会暨中国生态学学会海洋生态专业委员会2015年学术年会
• 发表日期: 2015年期

　　Ammonia is metabolic waste in most of teleost fish but too much ammonia surrounded is detrimental to fish.Toxicity and effect of NH2-N metabolization of different concentration of ammonia (0 mmol 1-1, 0.1 mmol 1-1, 0.3 mmol 1-1, 0.6 mmol 1-1, 1.1 mmol 1-1 NH4Cl) to juvenile marine medaka were investigated after chronic exposure (2+ months).High concentration of ammonia inhibited feed intake rate and decreased specific growth rate (SGR) of the fish.The ammonia excretion rate was about 10 times higher than the urea excretion rate which indicates that fish mainly excrete ammonia as nitrogenous waste.Ammonia accumulated in fish increased with ambient ammonia during the exposure period but it decreased with time progressed at the same group.