牙鲆对海水中铜的吸收、积累和排放规律

研究了牙鲆Paralichthysolivaceus内脏、肌肉、鳃组织对海水中Cu的吸收、积累和排放规律,以及海水中总有机碳(TOC)浓度和不同种类配体对Cu吸收的影响。试验结果表明,当Cu浓度为0 5mg/L时,各组织内Cu蓄积量随暴露时间的增加而增大,第13d均达到吸收平衡,各组织Cu蓄积量为内脏(971 89mg/kg干重)>肌肉(204 99mg/kg干重)>鳃(90 04mg/kg干重)。试验进行13d后,将牙鲆移入清洁海水中排放,结果表明,随着排放时间的增加,各组织Cu蓄积量下降,第8d接近排放平衡,各组织Cu排出率为肌肉(89%)>鳃(86 5%)>内脏(83 7%)。海水中TOC浓度及不同种类的配体对牙鲆吸收、蓄积Cu有明显影响,当TOC浓度相同时,孔石莼Ulvapertusa分泌物比牙鲆分泌物更能降低Cu的生物有效性;当配体相同时,随着TOC浓度的升高,各组织Cu蓄积量均明显下降,表明海水中TOC能降低Cu的生物有效性;海水中Cu2+的表观络合容量(ACu)随着TOC浓度的增加有明显上升趋势,并与TOC浓度呈线性相关。

Accumulation and elimination of copper in the tissues of Japanese flounder Paralichthys olivaceus

Accumulation and elimination of copper in viscera, muscle and gills of Paralichthys olivaceus and relation to total different organic carbons levels (TOC) in seawater were studied. The results indicated that copper accumulation in the tissues increased with the elapse of time at the concentration of 0.5 mg copper /L. At the equilibrium on day 13, the range of accumulation level of copper in the tissues in a descendant order was viscera mass (971.89 mg/kg) > muscle(204.99 mg/kg) > gill (90.04 mg/kg).During the depuration days, accumulation of copper in the tissues decreased with the elapse of time, and had reached equilibrium on day 8. The rate of elimination of copper from the fish tissues in an order of descend was muscle(89%) >gill(86.5%) > viscera (83.7%). The copper accumulation decreased significantly with the increase in TOC concentrations in the seawater because TOC could decrease the bioavailability of copper. The apparent complex capability of seawater to copper(A_(Cu)) increased with the increase in TOC concentration expressed as linear relationship. However, A_(Cu) did not have significant relationship with conditional stability constant (K_C).