Studies on the anemia of fish. VIII. Hemorrhagic anemia of carp caused by a herbicide, molinate.

Abstract

The toxicity of the herbicide, molinate, to carp was studied. The 21-day lethal centration for the animal was estimated at 0.18ppm. Anemia was found in carp exposed to molinate. This anemia was characterized with a drastic decrease of RBC and Hb levels. In blood smear preparations of carp with anemia, increase in number of immature erythrocyte was observed. However, no cytopathological change was found in their erythrocytes. Miccroaneurysm and punctuate hemorrhage were frequently observed in the gill of anemic carp. Histologically, these alterations consisted of swelling of gill lamella, dilatation and PAS-positive-thickening of capillary wall, and deterioration of pillar cells. No hemosiderin was demomstrated in the spleen of carp with anemia. Thus, it is concluded that herbicide, molinate evoked anemia in carp, and this anemia was due to loss of blood resulting from the alteration of gill-capillary wall.