fa تغییرات شاخص های مبتنی بر طول (LBI) ماهی هوور(Thunnus tonggol Bleeker, 1851) طی دو بازه زمانی در آبهای شمالی دریای عمان (استان سیستان و بلوچستان) تخصصي Special پژوهشي Research <span style="font-size:11pt"><span style="line-height:normal"><span style="direction:rtl"><span style="unicode-bidi:embed"><span style="font-family:Calibri,sans-serif"><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">ماهی هوور از مهمترین گونه های تون ماهیان و ماهیان اقتصادی های جنوب کشور بوده واز مدل شاخص های مبتنی بر طول</span></span><span dir="LTR" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""> (LBI) </span></span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">برای توصیف وضعیت ذخیره<b> </b>تون ماهی </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">هوور</span></span> <span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">در مناطق شمالی دریای عمان استفاده شد. </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">طی سال های 1373 و 1403 تعداد 3599 عدد ماهی بیومتری (زیست سنجی) گردید ( تعداد 2010 عدد&nbsp; در سال 1373 و 1589 عدد در سال 1403) و </span></span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">میانگین طولی (دامنه) ماهی&nbsp; هوور در سال 1373 میزان 22</span></span><span lang="AR-SA" style="font-size:12.0pt"><span cambria="" style="font-family:">&plusmn;</span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">71</span></span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar=""> (125-38) سانتی متر و در سال 1403 میزان 7</span></span><span lang="AR-SA" style="font-size:12.0pt"><span cambria="" style="font-family:">&plusmn;</span></span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">68 (122-28) سانتی متر بود</span></span><span dir="LTR" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">.</span></span> <span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">میانگین وزنی (دامنه) ماهی&nbsp; هوور در سال 1373میزان </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">2031</span></span><span lang="AR-SA" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">&plusmn;</span></span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar=""> 4231 (13000-1300)&nbsp; گرم و در سال 1403 میزان</span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">2581</span></span><span lang="AR-SA" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">&plusmn;</span></span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar=""> 5629 (22800-700) گرم بدست آمد. </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">با توجه به طول بلوغ محاسباتی این گونه (68</span></span> <span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">و65 سانتی متر برای سال های مورد مطالعه) میزان نمونه های زیر طول بلوغ در سال های 1373 و 1403 به ترتیب 32 درصد و 48&nbsp; درصد نتیجه شد ودرصد میزان زیر طول بلوغ سال های 1403 نسبت به سال 1373 تفاوت معنی داری داشت</span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">(05/0</span></span><span dir="LTR" style="font-size:12.0pt">P<</span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">).</span></span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar=""> رابطه طول چنگالی و وزن بدن</span></span> <span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">ماهی هوور برای سال 1373&nbsp; </span></span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">(80/0=</span></span><span dir="LTR" style="font-size:12.0pt">R²</span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">، 550=</span></span><span dir="LTR" style="font-size:12.0pt">N</span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">)^64/2</span></span><span dir="LTR" style="font-size:12.0pt">L</span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar=""> 067/0=</span></span><span dir="LTR" style="font-size:12.0pt">W</span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar=""> و سال 1403 (89/0=</span></span><span dir="LTR" style="font-size:12.0pt">R²</span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">، 450=</span></span><span dir="LTR" style="font-size:12.0pt">N</span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">)^59/2</span></span><span dir="LTR" style="font-size:12.0pt">L</span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar=""> 069/0=</span></span><span dir="LTR" style="font-size:12.0pt">W</span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar=""> بدست آمد و </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">میزان </span></span><span dir="LTR" style="font-size:12.0pt">b</span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar=""> رابطه طول و وزن نشانه دهنده رشد آلومتریک (ناهمسان) منفی بود. میانگین طولی بی نهایت برای سال های مورد مطالعه 1373 و 1403 به ترتیب&nbsp; </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">(105-133) 128 و (108-129) 125 سانتی متر و </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">&nbsp;طول حداکثر در سال 1373 مقدار 125 سانتی متر و در سال 1403 مقدار 122 سانتی متر بدست آمد. محدوده طول بهینه صید</span></span><span dir="LTR" style="font-size:12.0pt">(</span><span dir="LTR" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">Lopt</span></span><span dir="LTR" style="font-size:12.0pt">) </span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">&nbsp;برای سال های 1373 و 1403 ماهی هوور در آب های شمالی دریای عمان به ترتیب </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">(63-75) 73 و (59-74) 71 سانتی متر بدست آمد و نسبت شاخص میانگین طول به طول بهینه(</span></span><span dir="LTR" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">Lmean/Lopt</span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar=""> ) برای سال های مورد مطالعه به ترتیب 82/0 و 79/0 نتیجه شد. </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">دامنه </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">چشمه مناسب تور گوشگیر(</span></span><span dir="LTR" style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">MS</span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">) ماهی هوور درآب های شمالی دریای عمان سال های مورد مطالعه 1373 و 1403 به ترتیب </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">&nbsp;(15-13) 6/14</span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar=""> و </span></span>&nbsp;<span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">(15-13) 2/14 سانتی متر حاصل شد. </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">کاهش میانگین طول، افزایش </span></span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">درصد زیر طول بلوغ و نسبت میانگین طول به طول بهینه می تواند دلیلی بر وجود صید بی‌رویه ماهی هوور در </span></span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">در آبهای شمالی </span></span><span lang="FA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">دریای عمان (</span></span><span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">استان سیستان و بلوچستان)</span></span> <span lang="AR-SA" style="font-size:12.0pt"><span b="" style="font-family:" zar="">باشد. </span></span><span lang="AR-SA" style="font-size:12.0pt"><span style="font-family:"B Zar""></span></span></span></span></span></span></span><br> &nbsp; <span style="font-size:11pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="line-height:normal"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="background:#f8f9fa"><span new="" roman="" style="font-family:" times=""><span style="color:black">Longtail tuna</span></span></span></span><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""> fish is one of the most important tuna and economic fish species in the south of the country, and the length-based index (LBI) model was used to describe the status of the </span></span><i><span style="font-size:12.0pt"><span style="background:#f8f9fa"><span new="" roman="" style="font-family:" times=""><span style="color:black">Thunnus tonggol</span></span></span></span></i><b> </b><span style="font-size:12.0pt"><span style="background:#f8f9fa"><span new="" roman="" style="font-family:" times=""><span style="color:black">tuna</span></span></span></span><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""> stock in the northern areas of the Oman Sea. During 1994 and 2024, 3599 fish were biometrically measured (2010 in 1994 and 1589 in 2024), and the average length (range) of </span></span><i><span style="font-size:12.0pt"><span style="background:#f8f9fa"><span new="" roman="" style="font-family:" times=""><span style="color:black">T. tonggol</span></span></span></span></i><b> </b><span style="font-size:12.0pt"><span style="background:#f8f9fa"><span new="" roman="" style="font-family:" times=""><span style="color:black">tuna</span></span></span></span><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""> fish in 1994 was 71&plusmn;22 (125-38) cm and in 2024 it was 68&plusmn;7 (122-28) cm. The average weight (range) of the </span></span><span style="font-size:12.0pt"><span style="background:#f8f9fa"><span new="" roman="" style="font-family:" times=""><span style="color:black">longtail tuna</span></span></span></span><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""> fish in 1994 was 4231&plusmn;2031 (1300-13000) grams and in 2024 it was 5629&plusmn;2581 (700-22800) grams. Considering the calculated maturity length of this species (68 and 65 cm for the years under study), the percentage of specimens below maturity length in 1994 and 2024 was 32 percent and 48 percent, respectively, and the percentage of specimens below maturity length in 2024 was significantly different from that in 1994 (P<0.05).</span></span></span></span></span></span></span><br> <span style="font-size:11pt"><span style="text-justify:kashida"><span style="text-kashida:0%"><span style="line-height:normal"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times="">The relationship between the fork length and body weight of </span></span><i><span style="font-size:12.0pt"><span style="background:#f8f9fa"><span new="" roman="" style="font-family:" times=""><span style="color:black">T. tonggol</span></span></span></span></i><b> </b><span style="font-size:12.0pt"><span style="background:#f8f9fa"><span new="" roman="" style="font-family:" times=""><span style="color:black">tuna</span></span></span></span><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""> fish was obtained for the year 1994 W = 0.067 L^ 2.64 (R2=0.80, N=550) and for the year 2024 W = 0.069 L^ 2.59 (R2=0.89, N=450) and the b value of the length-weight relationship indicating allometric (asymmetric) growth was negative. The average infinite length for the years studied 1994 and 2024 was 128 (105-133) and 125 (108-129) cm, respectively and the maximum length in 1994 was 125 cm and in 2024 was 122 cm. The optimal catch length range (Lopt) for the years 1994 and 2024 of the </span></span><i><span style="font-size:12.0pt"><span style="background:#f8f9fa"><span new="" roman="" style="font-family:" times=""><span style="color:black">T. tonggol</span></span></span></span></i><b><span style="font-size:12.0pt"><span style="background:#f8f9fa"><span new="" roman="" style="font-family:" times=""><span style="color:black"> tuna</span></span></span></span></b><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""> fish in the northern waters of the Sea of ​​Oman was 73 (63-75) and 71 (59-74) cm, respectively, and the ratio of the mean length to the optimal length index (Lmean/Lopt) for the years under study was 0.82 and 0.79, respectively. The range of the mish size (MS) of the </span></span><i><span style="font-size:12.0pt"><span style="background:#f8f9fa"><span new="" roman="" style="font-family:" times=""><span style="color:black">T. tonggol</span></span></span></span></i><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""> fish in the northern waters of the Sea of ​​Oman in the years under study 1994 and 2024 was 14.6 (13-15) and 14.2 (13-15) cm, respectively. The decrease in the average length, the increase in the percentage below the maturity length and the ratio of the average length to the optimal length can be evidence of the existence of overfishing of the </span></span><span style="font-size:12.0pt"><span style="background:#f8f9fa"><span new="" roman="" style="font-family:" times=""><span style="color:black">longtail tuna</span></span></span></span><span style="font-size:12.0pt"><span new="" roman="" style="font-family:" times=""> fish in the northern waters of the Sea of ​​Oman (Sistan and Baluchestan Province).</span></span><i><span dir="RTL" lang="FA" style="font-size:12.0pt"><span style="font-family:"B Zar""></span></span></i></span></span></span></span></span><br> &nbsp; پایداری, وضعیت ذخیره , تون ماهی هوور. Sustainability, stock status, Thunnus tonggol 61 70 http://jair.gonbad.ac.ir/browse.php?a_code=A-10-133-73&slc_lang=fa&sid=1 Seyed Ahmadreza Hashemi سید احمدرضا هاشمی seyedahmad91@gmail.com 10031947532846009834 10031947532846009834 Yes Iranian fishery science reserch institute موسسه تحقیقات علوم شیلاتی کشور Mastooreh Doustdar مسطوره دوستدار mastooreh.doustdar@gmail.com 10031947532846009835 10031947532846009835 No Iranian fishery science reserch institute موسسه تحقیقات علوم شیلاتی کشور Rahimeh Rahmati رحیمه رحمتی rahmati764@gmail.com 10031947532846009836 10031947532846009836 No Iranian fishery science reserch institute موسسه تحقیقات علوم شیلاتی کشور