EFFECTS OF MICROCYSTIN-LR AND CYANOBACTERIAL CRUDE EXTRACTS ON EMBRYO-LARVAL DEVELOPMENT OF ZEBRAFISH (DANIO-RERIO)

Eggs of zebrafish (Danio rerio) were exposed to microcystin-LR at conc entrations of 0.5, 5 and 50 mu g litre(-1) from blastula stage up to t he end of embryonic development. No effects were observed during this period. After termination of exposure and transfer into microcystin-LR -free water, the evaluation at the end of the larval period showed dec reased survival at 5 and 50 mu g litre(-1) microcystin-LR. Furthermore , concentrations of 0.5, 5 and 50 mu g litre(-1) microcystin-LR retard ed larval growth. Far more pronounced effects occurred following expos ure with various aqueous cyanobacterial crude extracts from field samp les and batch cultures: gross malformations and high mortalities durin g embryonic development were observed. (C) 1997 Elsevier Science Ltd.