رابطه طول وزن و مقايسه برخي ويژگي‌هاي ريختي ماهي گورخري زاگرس Aphanius vladykovi Coad, 1988 در سرشاخه‌هاي رودخانه كارون در استان چهارمحال و بختياري

Length weight relationships and comparison between morphological features of Zagros toothcarp, Aphhanius vladykovi Coad, 1988 (Actinipterygii: Cyprinodontiformes) in upstreams of Karun River in Chaharmahalo Bakhtiari Province

به منظور تعيين روابط طول-وزن ماهي گورخري زاگرس (Aphanius vladykovi) و بررسي تغييرات صفات ريختي آن، 60 قطعه ماهي از چشمه مادردختر گندمان (30 قطعه با ميانگين طول استاندارد 01/4±71/32) و چشمه اردوال نقنه (30 قطعه با ميانگين طول استاندارد 92/3±72/30) طي فصل پاييز صيد گرديد. الگوي رشد هر دو جنس نر (06/2b=) و ماده (53/2=b) منطقه گندمان آلومتريك منفي و براي جنس‌هاي نر (20/3=b) و ماده نقنه (46/3=b) به ترتيب ايزومتريك و آلومتريك مثبت بود. فاكتور وضعيت بيانگر شرايط تغذيه‌اي بهتر منطقه گندمان نسبت به نقنه بود (05/0>P). مقايسه ريخت‌شناسي ماهيان حاكي از تنوع ريختي بالا بين دو منطقه بوده و نتايج آزمون آماري تحليل مؤلفه‌هاي اصلي (PCA)، عمق بدن را مهم‌ترين مؤلفه‌ي مؤثر بر تمايز ريختي جمعيت‌ها از يكديگر تشخيص داد. تجزيه‌ و تحليل تغييرات متعارف (CVA) ويژگي‌هاي ريخت‌سنجي نيز جمعيت‌هاي دو منطقه را از هم تفكيك كرد (05/0>P) اما هيچ تفاوت آماري معني‌داري بين جنس‌هاي نر و ماده هر منطقه نشان نداد (05/0

In order to estimate the length weight relationships and variations in the morphological straits of Aphanius vladykovi, 60 samples were caught from MadarDokhtar (mean standard Length: 32.71±4.01) and Ordoval springs (mean standard length: 30.72±3.92), during the fall season (30 specimens for each location). The growth pattern in Gandoman was negative allometric for both males (b=2.06) and females (b=2.53), while in Naghneh the growth pattern was Isometric and positive allometric for males (b=3.20) and females (b=3.46), respectively. The condition factor value (CF) indicated the better nutritional conditions in Gandoman compared to Naghneh (P<0.05). Based on morphological futures, a high morphological variation of A. vladykovi was observed across regions. Based on PCA, body depth is the variable with the greatest explanatory power. The populations were identified based on their locations across CVA (P<0.05) and no significant differences were observed between males and females in each location (P˃0.05). Consequently, it can be addressed that the differences in condition factors and morphological indices between two populations of A. vladykovi in two different upstream locations of Karun River are related to factors such as genetic potentials, habitat diversity as well as geographical distance. It seems that accumulation of distinctive traits under the effects of environmental parameters including temperature, nutrients and water depth is anticipated to be continued, so there is a probability of potentially allopatric speciation. Finally, it is proposed that the fishes of these two locations must be considered as two genetically and morphologically separated stocks in terms of fisheries conservation practices.