Toxicity of fatty acid 18:5n3 from Gymnodinium cf. mikimotoi: I. Morphological and biochemical aspects on Dicentrarchus labrax gills and intestine.
We present evidence for the toxic effects of fatty acid 18:5n3 (octadecapentaenoic acid) in the gills and intestine of the sea bass Dicentrarchus labrax. Light microscopic observation of gills showed strong mucus production and alteration of ionocytes. The Mg- and Na,K-ATPase activities were inhibited, with IC50 values of 10(-3) and 1.6 x 10(-4) M, respectively. Results are discussed in relation to osmoregulation.