芘污染对马氏珠母贝(Pinctada martensi)D型面盘幼虫发育的影响

多环芳烃(PAHs)是一类广泛存在于环境中的持久性有机污染物,大多具有潜在毒性、致癌性及致畸诱变作用。选取马氏珠母贝(Pinctada martensi)作为模式动物,研究芘对马氏珠母贝D型面盘幼虫发育的影响。将马氏珠母贝D型面盘幼虫暴露于不同浓度(2、4、8、16和32μg·L-1)芘(pyrene)中,在暴露后第12、24、36、48、60、72和84小时,分别测定其死亡率和畸形率,并观察形态学的变化。结果表明,芘对D型面盘幼虫的发育有显著影响,同一浓度组的死亡率与时间呈正相关。在2～32μg·L-1浓度范围内,不同暴露时间段,死亡率与浓度呈正相关。芘暴露对马氏珠母贝D型面盘幼虫的形态也有显著影响,随着芘浓度的增大幼虫畸形的比例增高,并呈现明显的剂量-效应关系,其中8和32μg·L-1浓度组的响应最敏感。同时,芘暴露对马氏珠母贝D型面盘幼虫的半数致死浓度(LC50)随着时间的推移逐渐降低,60h后趋于稳定,LC50值为43.50μg·L-1。研究结果表明,芘暴露能影响马氏珠母贝D型面盘幼虫的发育,并可能对其种群结构产生不利影响。

Effect of Pyrene Pollution on Development of D-shaped Veliger Larvae of Pinctada martensi

Polycyclic aromatic hydrocarbons (PAHs) is one of persistent organic pollutants ( POPs) with carcinogenicity,teratogenicity and mutagenicity,widespread throughout the environment. In this paper,the impacts of pyrene (Py) on the development and morphology of D-shaped veliger larvae of Pinctada martensi were studied. Mortality and aberration rate and the changes of morphology of D-shaped veliger larvae were recorded after Pinctada martensi exposed to different concentrations ( 2,4,8,16 and 32 μg·L-1 ) of Py for 12,24,36,48,72,and 84 hours. The results indicated that Py has significant toxic effect on the development of D-shaped veliger larvae in a time-dependent manner. The observed mortality was positively correlated to the concentrations of Py in the range of 2 ～ 32 μg·L-1 at different exposure times. Moreover,with increasing concentrations of Py,the percentages of abnormal individual increased significantly in a dose-dependent manner. Exposed to concentrations of 8 μg·L-1 and 32 μg·L-1 ,larvae were much more sensitive than that exposed to other concentration levels. With the passage of time, LC 50 firstly decreased then tended to be constant. The recorded 60 h-LC 50 was 43. 50 μg·L-1 . It can be concluded that Py exposure affected the development of D-shaped veliger larvae and could cause some adverse effect on the population structure of Pinctada martensi.