بررسي دوشكلي جنسي ماهي سفيد خزري (Rutilus kutum Kamenskii, 1901) با استفاده از روش ريخت‌سنجي هندسي در بخش جنوب‌غربي حوضه درياي خزر

Sexual dimorphism of Rutilus kutum Kamenskii, 1901 using geometric morphometric method in part of the southwestern Caspian Sea basin

اﯾﻦ ﺗﺤﻘﯿﻖ ﺑﻪﻣﻨﻈﻮر ﺑﺮرﺳﯽ دوﺷﮑﻠﯽ ﺟﻨﺴﯽ ﺻﻔﺎت رﯾﺨﺘﯽ ﻣﺎﻫﯽ ﺳﻔﯿﺪ درﯾﺎي ﺧﺰر )Rutilus kutum( ﺻﯿﺪ ﺷﺪه از ﺳﺎﺣﻞ رودﺳﺮ و ﺗﺎﻻب اﻧﺰﻟﯽ اﺳﺘﺎن ﮔﯿﻼن ﺑﺎ اﺳﺘﻔﺎده از روش رﯾﺨﺖﺳﻨﺠﯽ ﻫﻨﺪﺳﯽ ﻟﻨﺪﻣﺎرك ﭘﺎﯾﻪ ﺑﻪ اﺟﺮا درآﻣﺪ. از ﺳﻄﺢ ﺟﺎﻧﺒﯽ ﺳﻤﺖ ﭼﭗ ﻧﻤﻮﻧﻪﻫﺎ ﺑﻼﻓﺎﺻﻠﻪ ﭘﺲ از ﺻﯿﺪ ﻋﮑﺲﺑﺮداري ﺷﺪ و ﺳﭙﺲ ﺑﺎ اﺳﺘﻔﺎده از ﻧﺮم اﻓﺰار tpsDig2 ﺗﻌﺪاد 13 ﻧﻘﻄﻪ ﻟﻨﺪﻣﺎرك ﺗﻌﺮﯾﻒ و رﻗﻮﻣﯽ ﺳﺎزي ﮔﺮدﯾﺪ. ﺑﻪﻣﻨﻈﻮر ﺣﺬف اﺛﺮات ﻏﯿﺮ ﺷﮑﻞ از ﺟﻤﻠﻪ اﻧﺪازه، ﺟﻬﺖ و ﻣﻮﻗﻌﯿﺖ آﻧﺎﻟﯿﺰ ﭘﺮوﮐﺮاﺳﺖ ﺻﻮرت ﮔﺮﻓﺖ. ﺑﺎ اﺳﺘﻔﺎده از ﺗﺤﻠﯿﻞﻫﺎي ﻣﺆﻟﻔﻪﻫﺎي اﺻﻠﯽ )PCA( و ﺗﺎﺑﻊ ﺗﺸﺨﯿﺼﯽ )DFA( ﺑﺮاﺳﺎس ارزش P ﺣﺎﺻﻞ از Hoteling’s t-test ﻣﻘﺎﯾﺴﻪ ﺷﺪﻧﺪ. ﻧﺘﺎﯾﺞ ﺗﻔﺎوت ﻣﻌﻨﯽ داري را ﺑﯿﻦ دو ﺟﻨﺲ ﻧﺮ و ﻣﺎده از ﻟﺤﺎظ ﺷﮑﻞ ﺑﺪن ﻧﺸﺎن داد )0/05

This study was conducted to study sexual dimorphism of Caspian kutum, Rutilus kutum collected from the Rudsar coast and Anzali Wetland, Guilan Province. After collecting, the left lateral face of the fresh specimens were photographed, then 13 Landmark-points were defined and digitized using tpsDig2 software. Generalized procrustes analysis was performed to eliminate non-shape effects, including size, direction and position. Then date was analyzed using principal component analysis (PCA) and discriminant function analysis (DFA) based on P-value obtained from Hoteling’s t-test. The results showed a significant difference in the body shape of the male and female (P<0.05). The observed differences confirm the presence of the sexual dimorphism in the study species during reproductive season. The observed morphological can be shown presence of the sexual dimorphism in this species. Based on the findings, the females have deeper body and smaller head, which can related to reproductive performance of each sex.