苯并[a]芘对马氏珠母贝D型面盘幼虫发育的影响

苯并芘(Ba]P)已广泛分布于海洋环境中,低等海洋无脊椎动物从受精卵开始整个生长发育过程都面临着Ba]P等多环芳烃类污染物(PAHs)的威胁。本实验以热带海洋优势贝类马氏珠母贝(Pinctada maetensii)作为材料,研究Ba]P对马氏珠母贝D型面盘幼虫发育的影响。将幼虫暴露于不同浓度(1、2、4、10和15μg·L-1)Ba]P中,在暴露后第12、24、36、48、72、84小时,分别测定其D型面盘幼虫的死亡率和畸形数。结果表明:Ba]P对D型面盘幼虫死亡率的影响明显,死亡率与时间呈正相关,其中4和10μg·L-1浓度组的响应最敏感。在1～10μg·L-1浓度范围内,死亡率与浓度呈正相关;Ba]P暴露对马氏珠母贝D型面盘幼虫的形态也有显著影响,且随着浓度的增大产生畸形个体的时间越短。另外,Ba]P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后趋于稳定,48h时LC50趋于稳定,为21.56μg·L-1。研究表明,Ba]P对马氏珠母贝D形幼虫的发育具有不利影响,并可能影响其种群结构。

Impacts of B[a]P on the Development of Pinctada martensii D-shaped Veliger Larvae

Ba]P is the most studied polycyclic aromatic hydrocarbons (PAHs),which widely exists in the marine environment.Invertebrates are threatened by PAHs in their whole life.In this paper,the impacts of Ba]P on the development of D-shaped veliger larvae of Pinctada martensii were studied.When fertilized eggs growed up to D-shaped veliger larvae,they were exposed to Ba]P at six different concentrations of 0,1,2,4,10 and 15 μg·L-1.The mortality and aberration rate were calculated after D-shaped veliger larvae exposed for 12,24,36,48,72,and 84 hours.Results showed that the mortality was positive to exposure time.Ba]P has a significantly toxic effect on D-shaped veliger larvae of Pinctada martensii.Larvae in 4 and 10 μg·L-1 groups were much more sensitive than that in other groups.The morality was positive to the concentration of Ba]P in the range of 1～10 μg·L-1.Ba]P could significantly deform D-shaped veliger larvae.Moreover,exposed to high concentration of Ba]P resulted in the early appearence of the abnormal individual.Additionally,LC50 gradually decreased then kept a constant.48h-LC50 was 21.56 μg·L-1.The results indicated that Ba]P had negative effects on the developement of D-shaped veliger larvae of Pinctada martensii and their populative structure.