Surface structures of gill, scale and erythrocyte of Anabas testudineus exposed to sublethal concentration of cypermethrin

•We evaluated morphological changes on gill, scale and erythrocyte of fish exposed to cypermethrin.•The morphological changes were observed using scanning electron microscope.•We determined that cypermethrin caused morphological changes on the gills, scales and erythrocytes.

The present study was undertaken to assess the toxicity of sublethal concentrations (0.015, 0.030 and 0.045 ppm) of cypermethrin on the gills, scales and erythrocytes of Anabas testudineus for 21 days. The morphological changes on the gills, scales and erythrocytes of the A. testudineus were observed using scanning electron microscope (SEM). The SEM studies on all the three treated groups revealed several kinds of gills, scales and erythrocytes alterations and modifications with abnormal morphology. Gill alterations included highly active mucous cells, epithelial hyperplasia, fusion of secondary lamellae and epithelial lifting. The scales showed damaged lepidonts. Abnormal erythrocytes (shrunken cells), oozed out cytoplasmic content and lobopodial projections were observed in the erythrocytes of fish after exposure to cypermethrin.