The toxic effects of microcystin-LR on embryo-larval and juvenile development of loach, Misguruns mizolepis Gunthe.
Microcystin-LR, a specific and potent hepatotoxin, was tested for its effects on loach embryo-larval and juvenile development. The results of this study showed that loach embryos were more sensitive when exposed to microcystin-LR at a later than at an earlier stage of development. Juveniles were far less sensitive to MC-LR than were embryos and larvae. Mortality and developmental abnormality were proven to be dose-dependent and to be stage-specific sensitive. Among the abnormal changes noted were: pericardial edema and tubular heart, bradycardia, homeostasis, poor yolk resumption, small head, curved body and tail, and abnormal hatching. Liver and heart were the main targets of microcystin-LR toxicity. Ultrastructural analysis documented a complex set of sublethal effects of microcystin-LR on loach hepatocytes, chiefly including morphological alteration in nuclear and RER of loach liver cells. In addition, microcystin-LR was lethal to loach juvenile in the subacute (7 days) exposure (LC(50)=593.3 microg/l).
Liu
Yongding
Y
Institute of Hydrobiology, Chinese Academy of Science, Wuhan, 430072, Hubei, China. liuyd@ihb.ac.cn
Song
Lirong
L
Li
Xiaoyu
X
Liu
Tongming
T
D000818:Animals; D000013:Congenital Abnormalities / Q000209:etiology; D003531:Cypriniformes / Q000196:embryology* / Q000254:growth & development*; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian / Q000187:drug effects; D047108:Embryonic Development; D004791:Enzyme Inhibitors / Q000633:toxicity*; D005260:Female; D022781:Hepatocytes / Q000187:drug effects / Q000473:pathology; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D008099:Liver / Q000166:cytology; D008297:Male; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic / Q000633:toxicity*
D004791:Enzyme Inhibitors; D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; C057862:cyanoginosin LR