en Molecular Biology Molecular Biology پژوهشي Original research papers <p dir="ltr" style="text-align: justify;">Pick handle barracuda (<em>Sphyraena jello</em>) ) is one of the most important commercial species in the Persian Gulf. In order to investigate prevalence and intensity of nematoda, 150 <em>S. jello </em>&nbsp;from three sites (Khuzestan, Bushehr and Hormozgan provinces) of the Iranian coast of the Persian Gulf were monthly investigated in the period 2012-2013. The nematodes belonging to the genus <em>Hysterothylacium </em>(family <em>Raphidascarididae</em>) were isolated from the abdominal cavity and digestive tract with a prevalence of 12% and mean intensity of 4.8. Intensity of infestation was increased with size of the host (P<0.05). This study is the FIrst report of presence of the third and fourth- stage of an unreported type of the third and fourth- stage of an unreported type of Hysterothylacium &nbsp;larvae in <em>S. jello </em>&nbsp;from the Persian Gulf.</p> Sphyraena jello, Hysterothylacium sp., nematodes, Persian Gulf. 66 72 http://ijaah.ir/browse.php?a_code=A-10-35-29&slc_lang=en&sid=1 A Taheri Mirghaed 10031947532846001405 10031947532846001405 Yes Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran M Ghadam 10031947532846001406 10031947532846001406 No Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran H Ebrahimzadeh Mousavi 10031947532846001407 10031947532846001407 No Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran M Soltani 10031947532846001408 10031947532846001408 No Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran P Shohreh 10031947532846001409 10031947532846001409 No Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran H Rahmati Holasoo 10031947532846001410 10031947532846001410 No Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran I Mobedi 10031947532846001411 10031947532846001411 No Department of Parasitology, Faculty of Hygiene, Tehran University of Medical Sciences, Tehran, Iran A Banitalebi 10031947532846001412 10031947532846001412 No Department of Aquatic Animals Health & Diseases, Hormozgan Veterinary Organization, Bandar Abbas, Iran