ﺗﻐﯿﯿﺮات ﺿﺮﯾﺐ ﭼﺎﻗﯽ و ﺿﺮﯾﺐ ﭼﺎﻗﯽ ﻧﺴﺒﯽ ﻣﺎﻫﯽ ﮐﻔﺎل ﭘﻮزه ﺑﺎرﯾﮏ ( Chelon saliens) (در ﺳﻮاﺣﻞ ﺷﺮﻗﯽ درﯾﺎي ﺧﺰر (ﮔﻬﺮﺑﺎران(

Changes in Condition Factor and Relative Condition Factor of Chelon saliens in eastern part of the Caspian Sea (Goharbaran)

ﻫﺪف از اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺮر ﺳﯽ ﺗﻐﯿﯿﺮات ﺷﺎﺧﺺﻫﺎي ﻃﻮل، وزن، ﺿﺮﯾﺐ ﭼﺎﻗﯽ و ﺿﺮﯾﺐ ﭼﺎﻗﯽ ﻧﺴﺒﯽ ﻣﺎﻫﯽ ﮐﻔﺎل ﭘﻮزه ﺑﺎرﯾﮏ (Chelon saliens) در ﻓﺼــﻮل و اﻋﻤﺎق ﻣﺨﺘﻠﻒ در ﺳــﻮاﺣﻞ ﺷــﺮﻗﯽ درﯾﺎي ﺧﺰر در ﻣﻨﻄﻘﻪ ﮔﻬﺮﺑﺎران اﺳــﺖ. ﻣﻨﻄﻘﻪ ﮔﻬﺮﺑﺎران ﭼﻮن در ﻧﺰدﯾﮑﯽ ﺑﻨﺪر اﻣﯿﺮآﺑﺎد و ﻧﯿﺮوﮔﺎه ﻧﮑﺎ واﻗﻊ ﺷﺪه داراي ﺣ ﺴﺎ ﺳﯿﺘﯽ ﺧﺎص ا ﺳﺖ. در اﯾﻦ ﻣﻄﺎﻟﻌﻪ از ﺳﻪ روش ﺻﯿﺪ ﭘﺮه رﯾﺰ ﭼ ﺸﻤﻪ، دام ﮔﻮشﮔﯿﺮ و ﭘﺮه ﺻﯿﺎدي ﻃﯽ ﻣﺎهﻫﺎي آذر 1392 اﻟﯽ ﺗﯿﺮﻣﺎه 1393 ا ﺳﺘﻔﺎده ﺷﺪ. ﺑﺮ ا ﺳﺎس ﻧﺘﺎﯾﺞ ﺑﻪد ﺳﺖآﻣﺪه ﻣﻘﺪار b در راﺑﻄﻪ ﺑﯿﻦ ﻃﻮل ﭼﻨﮕﺎﻟﯽ و وزن ﻣﺎﻫﯽ ﮐﻔﺎل ﭘﻮژه ﺑﺎرﯾﮏ ﺑﺮاﺑﺮ 2/7651 ﮐﻪ ﺑﻪ ﻋﺪد 3 اﺧﺘﻼف ﻣﻌﻨﯽداري دارد (0.05>p) و داراي رﺷــﺪ آﻟﻮﻣﺘﺮﯾﮏ منفي ﺑﻮد. ﻣﺎﻫﯿﺎن رﯾﺰ در ﭘﺮه رﯾﺰ ﭼﺸﻤﻪ و ﻣﺎﻫﯿﺎن درﺷﺖ در ﭘﺮه ﺻﯿﺎدي ﺻﯿﺪ ﺷﺪﻧﺪ. ﻣﯿﺎﻧﮕﯿﻦ ﻃﻮل و وزن ﻣﺎﻫﯽ ﮐﻔﺎل ﭘﻮزه ﺑﺎرﯾﮏ در ﭘﺮه رﯾﺰ ﭼﺸــﻤﻪ، دام ﮔﻮشﮔﯿﺮ و ﭘﺮه ﺻــﯿﺎدي ازﻧﻈﺮ آﻣﺎري داراي اﺧﺘﻼف ﻣﻌﻨﯽداري ﺷــﺪﯾﺪي ﺑﻮدﻧﺪ (0.001>p). ﻣﯿﺎﻧﮕﯿﻦ ( اﻧﺤﺮاف ﻣﻌﯿﺎر±) ﺿــﺮﯾﺐ ﭼﺎﻗﯽ در ﺳــﻪ روش ﻣﺬﮐﻮر ﺑﻪ ﺗﺮﺗﯿﺐ 1/03±19/. ، 0/89±0/10، 79/.±0/09 و 0 و ﺿــﺮﯾﺐ ﭼﺎﻗﯽ ﻧﺴــﺒﯽ ﺑﻪ ﺗﺮﺗﯿﺐ 1/06±0/11 ،1/02±0/15 /92±11/. ﺑﺮآورد ﺷـــﺪ ﮐﻪ ازﻧﻈﺮ آﻣﺎري ﺑﯿﻦ آنﻫﺎ اﺧﺘﻼف ﻣﻌﻨﯽداري ﺑﻮد (0.05 >ANOVA; p. )ﻫﻤﭽﻨﯿﻦ ﺑﯿﻦ ﻣﯿﺎﻧﮕﯿﻦ ﺿـــﺮﯾﺐ ﭼﺎﻗﯽ و وزن ﻧﺴـــﺒﯽ در ردهﻫﺎي ﻃﻮﻟﯽ و ﻓﺼـــﻮل ﻣﺨﺘﻠﻒ ﻧﯿﺰ اﺧﺘﻼف ﻣﻌﻨﯽداري وﺟﻮد داﺷـــﺖ (0.001 >ANOVA; p). براساس نتايج اين تحقيق ماهيان با طول هاي بين 50-200در وﺿــﻌﯿﺖ ﺗﻐﺬﯾﻪ اي ﻣﻄﻠﻮب ﻗﺮار داﺷــﺘﻨﺪ و ﻣﺎﻫﯿﺎن درﺷت تر داراي داراي ﺷﺮاﯾﻂ ﺗﻐﺬﯾﻪ اي ﻣﻄﻠﻮﺑﯽ ﻧﺒﻮدﻧﺪ.

The main objective of the present study was investigation changes in length, weight, condition factor (CF) and relative condition factor (Kn) of Chelon saliens in different seasons and depths in eastern part of the Caspian Sea (Goharbaran region). Goharbaran region is a sensitive location because it is located near the Amirabad port and Neka Power Plant. In this study three fishing method, small mesh size beach seine, gillnet and commercial beach seine were used during January 2014 to July 2014. The result showed that the slope (b value) of the length-weight regression was 2.7651 was significantly different from 3 (P>0.05), indicating negative allometric growth. Small and large fishes were caught in small mesh size beach seine and commercial beach seine, respectively. The average length and weight were significantly different among three fishing methods (P<0.001). The average (±SD) CF of small mesh size beach seine, gillnet and commercial beach seine were 1.03±0.19, 0.89±0.10 and 0.79±0.09 and Kn were 1.02±0.15, 1.06±0.11 and 0.92±0.11, respectively. For both variables, there were significantly different among three fishing methods (ANOVA, P<0.05). Also, the averages KF and Kn significantly different among size classes and seasons (ANOVA, P<0.001). According to the average Kn, it can conclude that C. saliens with fork length between 50-200 mm has a good feeding and growth condition and the fish with length>200 mm has not suitable feeding and growth condition in the Goharabaran region.