藻华暴发期太湖不同湖区水样对斑马鱼胚胎发育及仔鱼生长毒性研究

为了评价太湖蓝藻暴发对生态系统的危害程度,于蓝藻水华暴发的2009年7月在太湖梅梁湾（M1和M2）、湖心区（H）和胥口湾（X）4个点采集水样,将斑马鱼（Danio rerio）胚胎直接暴露于水样中,研究太湖不同湖区水质对斑马鱼胚胎发育和仔鱼生长的影响。结果表明,暴露于梅梁湾M2点的斑马鱼胚胎畸形率为7%,显著高于空白组（K）（P〈0.01）,湖心H和梅梁湾M1点为5%左右,也高于空白组（P〈0.01）,而胥口湾X点和空白组无显著性差别（P〉0.05）。蓝藻暴发水体对斑马鱼胚胎产生致畸作用,表现为脊椎弯曲、尾部弯曲和心包水肿等。同时,不同湖区水样对仔鱼生存活力指数（SAI）的影响表明,梅梁湾M2点仔鱼活力最弱,胥口湾X点仔鱼活力最强。试验期间梅梁湾M2点蓝藻密度最高,胥口湾最低,太湖蓝藻密度的分布与斑马鱼胚胎发育的畸形频率具高度的一致性。因此,藻华暴发水体会对脊椎动物胚胎发育和仔鱼生长产生不利影响,危害水生态系统的安全。

Toxic Effect of Water Contained with Cyanobacterial Bloom on Embryo Development and Surviving Activity of Zebrafish in Lake Taihu,China

The cyanobacterial blooms in Lake Taihu has been recognized to be dangerous to aquatic ecosystems and human beings.To evalu-ate the healthy risk of the cyanobacterial bloom in Lake Taihu,the water samples were collected respectively from Meiliang Bay（M1 and M2）,center of Lake Taihu（H）and Xukou Bay of Lake Taihu to study the effects of the lake water on zebrafish early development in July 2009 when cyanobacterial bloom occurred seriously in Lake Taihu.In the study,zebrafish embryos were directly exposed to the water that was collected from the lake and the test water was updated daily.The results showed that the water samples contained with cyanbaocterial bloom from Lake Taihu had teratogenic effects on zebrafish embryos.The teratogenic defects included curved trunk,bended tails,and edema in pericardial sac.The teratogenicity rate of M2（up to 7%）was obviously higher than that of contro（lK）（P0.01）,H and M1（about 5%）was higher than K（P0.01）while there was no significant difference between X and K（P0.05）.Moreover,the SA（ISurviving Activity Index）of M2 was significantly lower than that of H,M1 and X.The results were consistent with the distribution of cyanobacteria’s density during the experimental period in Lake Taihu.Thus,The results suggested that the water samples contained cyanobacterial bloom from Lake Taihu were toxic to vertebrate early development.