Acute effects of an anatoxin-a producing cyanobacterium on juvenile fish -: Cyprinus carpio L.

The worldwide increase of eutrophication in fresh water bodies has caused cyanobacterial blooms to be more frequent. Anatoxin-a is a potent neurotoxin known to be produced by several genera of cyanobacteria including Anabaena. In this work, we exposed juvenile carps to freeze-dried cells of a toxic strain of the cyanobacterium Anabaena sp. during a 4-day period. Two different cell density-10(5) and 10(7) cell ml(-1) -were assayed. Lethality and anatoxin-a concentration in the whole fish were determined. In the higher cell density, all fish died between 26 and 29 h after exposure to toxin, whereas in the 10(5) cell ml(-1) density no deaths were observed. Levels of anatoxin-a in the whole fish ranged between 0.031 mu g g(-1) d.w. at the 105 cell ml(-1) concentration and 0.768 mu g g(-1) d.w. at 107 cell ml(-1) . Minor uptake of anatoxin-a occurred. (c) 2006 Elsevier Ltd. All rights reserved.