en fish disease fish disease پژوهشي Orginal research papers <span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-language: EN-US mso-fareast-language: EN-US">In this study a parasitological investigation on 238 samples of Neogobius species from the south-east of Caspian Sea was carried out. The samples including <i>Neogobius melanostomus </i>(35), <i>N. fluviatilis pallasi</i> (103),<i> N. kessleri gorlap </i>(70) and</span><i><span style="FONT-FAMILY: "Times New Roman","serif" COLOR: black FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-bidi-font-family: 'B Nazanin' mso-bidi-language: FA mso-ansi-language: EN-US mso-fareast-language: EN-US"> </span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-language: EN-US mso-fareast-language: EN-US">N. bathybius</span></i><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-language: EN-US mso-fareast-language: EN-US"> (30) were seasonally seined by beach net during one year (summer 2006-spring 2007), fixed in 10 <span dir="rtl"></span><span dir="rtl"></span><span dir="rtl" lang="FA"><span dir="rtl"></span><span dir="rtl"></span><font size="3" face="Times New Roman">%</font></span><span dir="ltr"></span><span dir="ltr"></span><span lang="FA"><span dir="ltr"></span><span dir="ltr"></span><font size="3" face="Times New Roman"> </font></span>buffer formalinand transferred to the laboratory. From 231 of examined fishes 235 specimens were infected (97/6 %). The collected parasites were as follows: <i>Hysterothylacium aduncum, Raphidascaris acus, Cucullanus sphaerocephalus, Dichelyne minutus, Raphidascaroides sp., Cystidicola sp,.</i></span><i><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-bidi-font-family: 'B Nazanin' mso-bidi-language: FA mso-ansi-language: EN-US mso-fareast-language: EN-US"> Gyrodactylus </span><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-language: EN-US mso-fareast-language: EN-US">sp., </span></i><span style="FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: 'Times New Roman' mso-bidi-language: FA mso-ansi-language: EN-US mso-fareast-language: EN-US">and <i>Corynosoma strumosum.</i> Hereby, <i>N.melanostomus </i>is introduced as a new host for <i>Raphidascaroides sp., C. sphaerocephalus</i> and<i> Cystidicola sp.</i>. <i>N. fluviatilis pallasi</i> and<i> N. kessleri gorlap </i>for<font size="3"><font face="Times New Roman"><span style="COLOR: red"> </span><i>C. sphaerocephalus, Cystidicola sp. </i>and<i> H .adunacum. N. bathybius</i> for <i>C. sphaerocephalus, Cystidicola sp., H. aduncum, E.excisus, R. acus </i>and <i>C. strumosum.</i> <i>Cystidicola sp.</i> and <i>H. adunacum </i>were reported for the first time from <country-region w:st="on"><place w:st="on">Iran</place></country-region>. Among the investigated fishes <i>N. fluviatilis pallasi</i> possessed the highest and <i>N. bathybius</i> the lowest variety in infection with various species of parasites. The results of this study indicated that there are significant relations between total length (T.L.) and weight in <i>N. fluviatilis pallasi</i> with the number of <i>C. sphaerocephalus, D. minutus </i>and<i> E. excises. </i>Also<i> </i>there are significant relations between total length and weight in<i> N. melanostomus </i>and<i> </i>between<i> </i>weights<i> </i>in<i> N. kessleri gorlap </i>with<i> </i>the number of <i>C. sphaerocephalus.</i></font></font></span> Neogobiidea, Nematoda, Acanthocephala, Monogena, Caspian Sea 95 104 http://jifro.ir/browse.php?a_code=A-10-1-64&slc_lang=en&sid=1 J. Pazooki pazooki2001@yahoo.com 10031947532846001092 10031947532846001092 Yes Z. Mansouri-Habibabadi 10031947532846001093 10031947532846001093 No M. Masoumian 10031947532846001094 10031947532846001094 No A. Aghaee-Moghadam 10031947532846001095 10031947532846001095 No