fa Parasitic Diseases Parasitic Diseases پژوهشي Original research papers <p><em>Ligula intestinalis </em>originally is belongs to Cestoda parasite that infests a range of fish family especially Cyprinidae. It is also a zoonosis parasite that affects fish and probably human health. This study tried to isolate <em>L. intestinalis </em>from Sea bream (<em>Abramis brama Orientalis</em>), an species classified in family, Cyprinidae, from Caspian Sea. Sixty Sea bream were caught from Caspian Sea, Babolsar Fisheries port. Among that, 26.66% were infected with <em>L. intestinalis</em>. The tissues of infected fishes including gonads, liver and kidney were examined for pathological findings. Ovaries changes showed fibrosis, infiltration of inflammatory cells, atrophy of oocytes; testicular hyperemia, necrosis, fibrosis and degeneration; kidneys necrosis, destruction of tubules, vacuolar degeneration; and liver vacuolar degeneration, biliary duct hyperplasia, necrosis, lymphatic vessel dilatation, fibrosis&nbsp;and cholestasis. Considering the effect of <em>L. intestinalis </em>on fish and human health, the prevention programs to disturb the cycle of parasite and more monitoring studies in fish epidemiology especially food fish are recommended.</p> Ligula intestinalis, Abramis brama, Histopathology 34 43 http://ijaah.ir/browse.php?a_code=A-10-35-36&slc_lang=fa&sid=1 A Bozorgnia 10031947532846001425 10031947532846001425 No Faculty of Veterinary Medicine, Islamic Azad University, Ghaemshahr branch, Ghaemshahr, Iran Sh Omidzahir 10031947532846001426 10031947532846001426 Yes Faculty of Marine Sciences, University of Mazandaran,Babolsar, Iran S M Hoseini 10031947532846001427 10031947532846001427 No Faculty of Veterinary Medicine, Islamic Azad University, Babol branch, Babol, Iran Sh Darzi 10031947532846001428 10031947532846001428 No Faculty of Veterinary Medicine, Islamic Azad University, Ghaemshahr branch, Ghaemshahr, Iran