Changes in Sublethal Effects, Oxygen Consumptin, and Ammonia Excretion of Grey Mullet (Mugil cephalus) Under Various Salinities and Lead Concentrations

烏魚（Mugil cephalus）暴露在不同鹽度及鉛濃度下其半致死效應、耗氧率、及排氨率之變化

王河順(He-Shun Wang) ； 李純慧(Chun-Huei Li) ； 鄭學淵(Sha-Yen Cheng)

《臺灣水產學會刊》 39卷3期 (2012/09) Pp. 187-198

https://doi.org/10.29822/JFST.201209.0005

摘要

本研究探討烏魚幼魚（Mugil cephalus）在不同鹽度（0千分之一、17千分之一、及34千分之一）、鉛濃度及暴露時間組合下，對致死、耗氧、排氨之研究。烏魚暴露在鹽度17千分之一下對鉛最具耐受性，在鹽度0千分之一、17千分之一、及34千分之一環境下，烏魚對鉛之96小時LC50 （半致死濃度） 分別為1.65、5.21、及4.39 mg Pb2＋／l，LT50 （半致死時間）也出現相同趨勢。控制組烏魚於鹽度0千分之一、17千分之一、及34千分之一環境下，其耗氧率分別為733.97、801.78、及890.21 μg／g／h，排氨率分別為17.792、11.587、及10.802 μg／g／h。經過鉛0.5 mg／l暴露20天後，在鹽度0千分之一、17千分之一及34千分之一下，耗氧率分別下降至450.32、484.57、及516.27 μg／g／h，排氨率分別下降至1.134、0.939、及0.646 μg／g／h。

關鍵字

烏魚 ； 鉛 ； 半致死效應 ； 耗氧率 ； 排氨率 ； 鹽度

並列摘要

The present study investigated the sublethal concentration, sublethal time, oxygen consumption, and ammonia excretion of grey mullet (Mugil cephalus) fry following exposure to different lead concentrations at various salinities (0 1 per mille, 17 1 per mille, and 34 1 per mille). Fish exposed to 17 1 per mille were the most tolerant to lead. Respective 96-h 50% lethal concentration (LC50) values were 1.65, 5.21, and 4.39 mg Pb2+/l following exposure to 0 1 per mille, 17 1 per mille, and 34 1 per mille salinities. Examination of the time to 50% lethality (LT50) also showed the same trend at salinities of 17 1 per mille ＞ 34 1 per mille ＞ 0 1 per mille. Oxygen consumption and ammonia excretion by M. cephalus were measured in individual fish exposed to different salinities (0 1 per mille, 17 1 per mille, and 34 1 per mille) and 0.5 mg/l lead. Oxygen consumption of the fish directly increased with a higher ambient salinity. In control solution, the oxygen consumption of mullet exposed to 0 1 per mille, 17 1 per mille, and 34 1 per mille salinities were 733.97, 801.78, and 890.21 μg/g/ h, respectively. The ammonia excretion of mullet exposed to 0 1 per mille, 17 1 per mille, and 34 1 per mille salinities were 17.792, 11.587, and 10.802 μg/g/h, respectively. In fish exposed to 0.5 mg/l lead and different salinities (0 1 per mille, 17 1 per mille, and 34 1 per mille) for 20 days, oxygen consumption rates respectively decreased to 450.32, 484.57, and 516.27 μg/g/h. Ammonia excretion directly decreased with higher ambient salinities. After 20 days of exposure, respective ammonia excretion rates were 1.134, 0.939, and 0.646 μg/g/h in grey mullet acclimated to 0 1 per mille, 17 1 per mille, and 34 1 per mille salinities.

並列關鍵字

Grey mullet ； Lead ； Lethal effect ； Oxygen consumption ； Ammonia excretion ； Salinity