The destructive effects of Diazinon on gill tissue of Caspian roach fingerling (Rutilus caspicus)

One hundred and five fish with an average weight of 2.5 g from the aquaculture center in the port of Turkmen, Golestan province, were cached, sub-lethal test was for 1 week with 5 treated of diazinon as 0, 25, 50, 75 and 90% of LC50 (0, 0.42, 0.85, 1.28 and 1.17 ppm, respectively). The results showed that with progress of poison, gill tissue lesions will be increased such as hyperemia and hemorrhage, fractures and secondary lamellar connection, one-way and two-way lamellar cast gill and shorten the secondary lamellar, swollen, multicellular be harder to lamella.