en hematology hematology پژوهشي Original research papers <span style="font-size:11pt"><span style="line-height:140%"><span style="vertical-align:top"><span style="font-family:Calibri,sans-serif"><span lang="TR" style="font-size:12.0pt"><span style="line-height:140%"><span new="" roman="" style="font-family:" times=""><span style="color:black">Contracaecum is a genus ofitic nematodes to the family Anisakidae, commonly found in fish as intermediate hosts to reach their definitive hosts. To assess the effect of this parasite on the haematological parameters of common carp (<i>Cyprinus carpio</i>), a total of 60 fish were collected alive from the Parishan basin in Kazerun, Fars Province, Iran. Among these, 50% were infected with L3 larvae of <i>Contracaecum</i> sp., with an average intensity of 16.7 &plusmn; 2.03 helminths per fish. The fish were analyzed to establish various haematological parameters. The haematological analysis revealed significant reductions in haematocrit (HCT) and red blood cells (RBCs), while lymphocyte counts showed no significant change. </span></span></span></span></span></span></span></span><br> <span style="font-size:11pt"><span style="line-height:150%"><span style="vertical-align:top"><span style="font-family:Calibri,sans-serif"><span lang="TR" style="font-size:12.0pt"><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""><span style="color:black">White blood cells (WBCs) increased non-significantly (<i>p</i>>0.05), but monocytes and neutrophils exhibited a significant increase (<i>p</i>&le;0.05). Variations between lymphocyte and WBC counts demonstrated non-significant differences (<i>p</i>>0.05) between infected and non-infected groups, whereas the other parameters showed significant differences (<i>p</i>&le;0.05). Basophil and eosinophil values were not evaluated due to zero counts, resulting in no statistical analysis for these parameters.</span></span></span></span><span lang="TR" style="font-size:12.0pt"><span style="line-height:150%"><span new="" roman="" style="font-family:" times=""><span style="color:black"></span></span></span></span></span></span></span></span> Cyprinus carpio, Hematology, Contracaecum sp., Nematodes 1 12 http://ijaah.ir/browse.php?a_code=A-10-328-2&slc_lang=en&sid=1 A.R. Golchin Manshadi golchinalireza@yahoo.com 10031947532846003166 10031947532846003166 Yes 1 Department of Veterinary science, Kazerun Branch, Islamic Azad University, Kazerun, Iran F. Shahandeh 10031947532846003167 10031947532846003167 No 2 Gratuated of Faculty of veterinary Medicine, Kazerun Branch, Islamic Azad University, Kazerun, Iran