三疣梭子蟹体内As的蓄积特异性研究

Study on the Accumulation Specificity of Arsenic in Portunus trituberculatus

本研究以三疣梭子蟹(Portunus trituberculatus)为实验生物,应用半静态双箱模型的方法在室内模拟了三疣梭子蟹对砷(As)生物富集过程,As暴露浓度梯度分别为5、20和100μg/L。通过对三疣梭子蟹体内总砷含量变化进行非线性拟合,得到其对总砷的生物富集系数(BCF)、生物富集动力学参数。结果显示,三疣梭子蟹肝胰腺组织对总砷的BCF明显高于肌肉组织。到富集实验结束时,三疣梭子蟹肝胰腺组织中由低到高浓度组对总砷的BCF分别为21.21、15.07和10.31,吸收速率常数(k1)及BCF均随水体中As浓度的增加而减少;肌肉组织中,由低到高浓度组对总砷的BCF分别为5.17、3.74和5.83,5、100μg/L实验组各动力学参数较为接近,但20μg/L实验组的富集速率常数k1最小,释放速率常数(k2)最大。研究表明,三疣梭子蟹BCF和生物学半衰期B1/2最小。

Heavy metal pollution in marine environments has become a prominent environmental problem.Many domestic and overseas scholars have conducted a great deal of research on the heavy metal pollution characteristics and accumulation specificity in crustaceans.Economically important crustaceans in aquaculture such as the Whiteleg shrimp(Penaeus vannamei),Summer flounder(Paralichthys dentatus),yellow croaker(Larimichthys crocea),Chesapeake blue crab(Callinectes sapidus),and Japanese blue crab(Portunus trituberculatus)are very popular foods but also have a high arsenic-enrichment factor.One of the most economically important marine aquaculture crabs in China,P.trituberculatus,has recently increased in popularity due to its high nutritional value and desirable flavor.The bioaccumulation of arsenic in the Gazami crab(Portunus trituberculatushas)has not been reported.Exploring the accumulation specificity of arsenic in P.trituberculatus provides the scientific data necessary to determine safe thresholds and arsenic limit in marine aquaculture.In our study,bioaccumulation of arsenic was studied in P.trituberculatus and simulated using the two-compartment model.The exposure concentration gradients of arsenic were 5,20,and 100μg/L.We analyzed data with non-linear curve fitting,obtaining the kinetic parameters such as bioconcentration factor(BCF),uptake rate constant(k1),elimination rate constant(k2),and biological half-life(B1/2).The results showed that the BCF of arsenic in the hepatopancreas was significantly higher than muscle.At the end of the enrichment experiment,the BCFs of arsenic in the hepatopancreas tissues of P.trituberculatus from low to high concentration groups were 21.21,15.07,and 10.31,respectively.The uptake rate constant k1 and the BCF decreased with the increase of the aquatic arsenic concentration.The BCFs of arsenic in the muscle from low to high concentration groups were 5.17,3.74,and 5.83,respectively.The kinetic parameters of the 5μg/L and 100μg/L experimental groups were similar.However,the uptake rate constant k1 was the smallest.The elimination rate constant k2 was the largest in the 20μg/L experimental group,while the BCF and B1/2 were the smallest.