ﺗﻨﻮع رﯾﺨﺘﯽ اﺳﺘﺨﻮان ﯾﻮروﻫﯿﺎل: ارﺗﺒﺎط آن ﺑﺎ اﺑﻌﺎد ﺳﺮ و ﺗﻨﻮع رﯾﺨﺘﯽ ﻣﺎﻫﯽ

Morphological variation of urohyal bone: Its relation to dimensions of the head and variety of fish morphology

اﺳﺘﺨﻮان ﯾﻮروﻫﯿﺎل ﺳﺎﺧﺘﺎري ﺳﺨﺖ در ﺳﺮ ﻣﺎﻫﯽ ﻣﯽ ﺑﺎﺷﺪ ﮐﻪ ﻧﻘﺶ ﺑﺴﺰاﯾﯽ در ﻣﮑﺎﻧﯿﺴﻢ ﺑﺎز و ﺑﺴﺘﻪ ﺷﺪن دﻫﺎن و در ﻧﺘﯿﺠﻪ ﺗﻐﺬﯾﻪ ﻣﺎﻫﯽ دارد. ﺑﻨﺎﺑﺮاﯾﻦ، ﯾﮑﯽ از ﻓﺮ ﺿﯿﺎت ﻣﻬﻢ در راﺑﻄﻪ ﺑﺎ ﺗﻨﻮع ﺷﮑﻠﯽ ا ﺳﺘﺨﻮان ﯾﻮروﻫﯿﺎل اﯾﻦ ا ﺳﺖ ﮐﻪ ﺷﮑﻞ آن ﻋﻼوه ﺑﺮ اﻟﮕﻮي ﺗﻐﺬﯾﻪ ﻣﺎﻫﯽ، ﻣﺘﺎﺛﺮ از رﯾﺨﺖﺷﻨﺎﺳﯽ ﺧﺎرﺟﯽ ﺑﺪن ﻣﺎﻫﯿﺎن و ﺑﻮﯾﮋه اﺑﻌﺎد ﺳﺮ ﻣﺎﻫﯿﺎن اﺳﺖ. از اﯾﻨﺮو، ﺷﻨﺎﺧﺖ و ﻣﻄﺎﻟﻌﻪ وﯾﮋﮔﯽﻫﺎي ﮐﻤﯽ و ﮐﯿﻔﯽ ﯾﻮروﻫﯿﺎل ﻣﯽﺗﻮاﻧﺪ ﯾﮏ ﻣﻌﯿﺎر ﻣﻨﺎﺳﺐ ﺟﻬﺖ ﺷﻨﺎﺳﺎﯾﯽ ﻣﺎﻫﯿﺎن، ﻣﻄﺎﻟﻌﺎت اﮐﻮﻟﻮژﯾﮑﯽ و ﻧﯿﺰ ﻣﻄﺎﻟﻌﺎت ﻣﺮﺗﺒﻂ ﺑﺎ رﻓﺘﺎرﻫﺎي ﺗﻐﺬﯾﻪ اي ﻣﺎﻫﯿﺎن ﺑﺎﺷـﺪ. در اﯾﻦ ﻣﻄﺎﻟﻌﻪ، ﺗﻨﻮع ﺷـﮑﻠﯽ ﻫﺸـﺖ ﮔﻮﻧﻪ ﻣﺎﻫﯽ درﯾﺎﯾﯽ ﺑﺎ ﺗﻨﻮع رﯾﺨﺘﯽ اﺳـﺘﺨﻮان ﯾﻮرﻫﯿﺎل آﻧﻬﺎ ﻣﻘﺎﯾﺴـﻪ ﺷـﺪه اﺳـﺖ ﺗﺎ ﺷﻨﺎﺧﺖ ﺑﯿ ﺸﺘﺮي از اﻟﮕﻮي ﺗﻐﯿﯿﺮات اﯾﻦ ا ﺳﺘﺨﻮان در ﻣﺎﻫﯿﺎن ﺑﺪ ﺳﺖ آﯾﺪ. ﺑﺮ ا ﺳﺎس اﯾﻦ ﻣﻄﺎﻟﻌﻪ، ﺳﻄﺢ ﺷﮑﻤﯽ ﯾﻮروﻫﯿﺎل ﻣﺘﻨﺎ ﺳﺐ ﺑﺎ ﺳﻄﺢ ﺷﮑﻤﯽ ﺳﺮ و ﺳﻄﺢ ﺟﺎﻧﺒﯽ ﯾﻮروﻫﯿﺎل ﻣﺘﻨﺎﺳﺐ ﺑﺎ ارﺗﻔﺎع ﺳﺮ در ﻣﺎﻫﯿﺎن اﺳﺖ. ﺑﻨﻈﺮ ﻣﯽرﺳﺪ ﮐﻪ اﯾﻦ اﻟﮕﻮي ﺗﻐﯿﯿﺮات در ﺑﺪن ﻣﺎﻫﯽ، اﺑﻌﺎد ﺳﺮ ﻣﺎﻫﯽ و ﺷﮑﻞ ا ﺳﺘﺨﻮان ﯾﻮروﻫﯿﺎل ﺑﻬﺘﺮﯾﻦ و ﮐﺎراﻣﺪﺗﺮﯾﻦ ﺳﺎزﮔﺎري در راﺑﻄﻪ ﺑﺎ ﺗﻐﺬﯾﻪ ﻣﺎﻫﯿﺎن از زﯾﺴﺘﮕﺎﻫﻬﺎي ﻣﻨﺤﺼﺮ ﺑﻪ ﻓﺮد خودﺷﺎن ﻣﯽ ﺑﺎﺷﺪ.

Urohyal bone is a hard structure in the head of fishes that plays a significant role in the opening and closing of the mouth and consequently the feeding of fish. Therefore, one of the most important issues with regard to the shape variety in urohyal bone is that in addition to the pattern of fish nutrition, the overall shape of this bone is influenced by external morphology of fish body, and especially dimension of the fish head. Therefore, recognizing and studying the qualitative and quantitative characteristics of this bony structure can be a suitable criterion for identifying fish, ecological studies, and also studies related to the nutritional behavior of fishes. In this research, morphological variation of eight marine fish species has been compared with variety seen in their urohyal bone for a better understanding of the pattern of variation in structure in fishes. According to this study, the shape of ventral surface of urohyal bone is appropriate to the ventral surface of the head, and the lateral surface of the urohyal corresponding to the height of the fish head. It seems that this pattern of changes in fish body, size of the head and the shape of urohyal bone is the best and most effective adaptation to the feeding of fish in their unique habitats.