مطالعه ريخت‌شناسي جمجمه لاك‌پشت خزري Mauremys caspica (Gemelin, 1774) (Testudines: Geoemydidae) در غرب ايران

Cranial study of the Caspian freshwater turtle, Mauremys caspica (Gmelin, 1774) (Testudines: Geoemydidae) in Western Iran

ﺳﺎﺧﺘﺎر رﻳﺨﺖ ﺷﻨﺎﺳﻲ ﺟﻤﺠﻤﻪ و ﻣﻨﺸﺎء ﻻكﭘﺸﺖ ﻫﺎ ﻳﻜﻲ از ﻃﻮﻻﻧﻲ ﺗﺮﻳﻦ ﺑﺤﺚﻫﺎ در ﺗﺤﻘﻴﻘﺎت ﺗﻜﺎﻣﻠﻲ ﺑﻮده اﺳﺖ. ﺗﻐﻴﻴﺮ ﺟﻤﺠﻤﻪ ﺑﻪ ﺷﻜﻞ آﻧﺎﭘﺴﻴﺪ، آن را ﺑﻪ ﻳﻚ ﺳﺎﺧﺘﺎر ﺑﺪون ﺣﺮﻛﺖ و ﻣﻨﺤﺼﺮ ﺑﻪ ﻓﺮد ﺗﺒﺪﻳﻞ ﻛﺮده اﺳﺖ ﻛﻪ ﻗﺎﺑﻠﻴﺖ ﺗﻐﻴﻴﺮ ﻣﺴﻴﺮ ﻋﻀﻠﻪ ﺟﻤﻊ ﻛﻨﻨﺪه آرواره را دارد. اﻳﻦ ﺗﻐﻴﻴﺮات ﺑﻪ ﺷﺪت ﺑﺎ ﺳﺎزﮔﺎريﻫﺎي ﻋﻤﻠﻜﺮدي، ﺑﻪ وﻳﮋه ﺑﺎ ﻛﺎراﻳﻲ ﮔﺎز ﮔﺮﻓﺘﻦ ارﺗﺒﺎط دارد. ﻣﻄﺎﻟﻌﻪ ﺣﺎﺿﺮ اوﻟﻴﻦ ﺷﺮح ﻣﻔﺼﻞ از اﺳﺘﺨﻮان ﺷﻨﺎﺳﻲ ﺟﻤﺠﻤﻪ ﻻكﭘﺸﺖ ﺑﺮﻛﻪ اي ﺧﺰري Mauremys caspica در ﻏﺮب اﻳﺮان را اراﺋﻪ ﻣﻲدﻫﺪ. ﻧﻤﻮﻧﻪ-ﻫﺎي ﻣﻮرد آزﻣﺎﻳﺶ از رودﺧﺎﻧﻪ دﻳﻨﻮر در اﺳﺘﺎن ﻛﺮﻣﺎﻧﺸﺎه ﺟﻤﻊ آوري ﺷﺪهاﻧﺪ. ﺑﺎ اﺳﺘﻔﺎده از ﺷﻴﻮهﻫﺎي راﻳﺞ ﺑﺮاي ﭘﺎﻛﺴﺎزي اﺳﺘﺨﻮان ﻫﺎ، ﺟﻤﺠﻤﻪ ﻫﺎ ﺟﺪا و ﭘﺎﻛﺴﺎزي ﺷﺪ و ﺗﻮﺳﻂ اﺳﻜﻨﺮ اﺳﻜﻦ ﺻﻮرت ﮔﺮﻓﺖ و ﺑﺎ اﺳﺘﻔﺎده از ﻟﻮپ ﻣﺠﻬﺰ ﺑﻪ دورﺑﻴﻦ دﻳﺠﻴﺘﺎﻟﻲ ﻋﻜﺴﺒﺮداري اﻧﺠﺎم ﺷﺪ. ﻧﺘﺎﻳﺞ ﺑﺪﺳﺖ آﻣﺪه ﻧﺸﺎن ﻣﻲدﻫﺪ ﻛﻪ Mauremys caspica داراي ﺳﺎﺧﺘﺎري وﻳﮋه اﺳﺘﺨﻮاﻧﻲ ﻣﺸﺘﻤﻞ ﺑﺮ 39 )18 ﺟﻔﺖ و 3 اﺳﺘﺨﻮان ﻣﻨﻔﺮد( اﺳﺘﺨﻮان اﺳﺖ ﺑﺎ ﻳﻚ ﺳﻘﻒ ﺟﻤﺠﻤﻪ ﺻﺎف، ﺑﺴﻴﺎري از ﻋﻨﺎﺻﺮ ﺟﻤﺠﻤﻪ اي ﺑﻪ ﺷﺪت ﭘﻬﻦ و ﻳﻚ ﺟﻤﺠﻤﻪ ﻋﺼﺒﻲ ﻓﺸﺮده ﻛﻪ اﺣﺘﻤﺎﻻً ﻧﺘﻴﺠﻪ ﻋﻤﻠﻜﺮدي ﻧﺎﺷﻲ از ﺳﺒﻚ زﻧﺪﮔﻲ اﺳﺖ، ﻧﺘﺎﻳﺞ ﻣﺎ ﻧﺸﺎن ﻣﻲ دﻫﺪ ﻛﻪ ﺗﻨﻮع ﺧﺎص در اﺳﺘﺨﻮان ﺷﻨﺎﺳﻲ ﺟﻤﺠﻤﻪ ﻣﺎﻧﻨﺪ اﺑﻌﺎد، ﺷﻜﻞ، ﻣﺤﻞ ﻗﺮار ﮔﻴﺮي و ﻣﻔﺼﻞ ﺑﻨﺪي ﻣﻲ ﺗﻮاﻧﺪ ﺗﺄﺛﻴﺮ در رﻓﺘﺎر ﺗﻐﺬﻳﻪ اي ﺟﺎﻧﻮر داﺷﺘﻪ ﺑﺎﺷﺪ.

The skull morphology and origin of turtles is one of the long-lasting debates in evolutionary researchs. Skull change to anapsid, transformed that to an akinetic and unique structure capable of reorienting the jaw contracting muscle. These changes are thought to be strongly related to functional adaptations, especially biting performance. The present study provides detailed description of the osteocranial structure of the Caspian terrapin, Mauremys caspica, in western Iran. Examined specimens were collected from Dinavar river in Kermanshah Province. Using common protocols for bone cleansing, the skulls were removed and scanned, and photographed using a loop equipped with digital camera. The skull of Testudo graeca encompass 39 bones (18 pairs and three single bones) that is including a flat skull roof, numerous extremely wide skull elements, and a compressed neurocranium possibly the functional result of life habit, Our results showed that specific variations in skull osteology, including scale, shape, location and articulation, can have different effects on animal behavior.