Effect of different concentration of cypermethrin on various histological structure of smooth muscles of Schizothorax esocinus. (A) Control showing normal fish muscle having no necrosis and fragmentation. (B) fish exposed to 1 ppm showing (MN) Muscles necrosis. (C) fish exposed to 2 ppm showing (FS) Fragmentation of sarcoplasm and (MN) Muscles necrosis. (D) fish exposed to 3 ppm showing (MN) Muscles necrosis and (FS) Fragmentation of sarcoplasm. (E) fish exposed to 4 ppm showing (FS) Fragmentation of sarcoplasm.