زيست شناسي توليدمثل سياه ماهي (Capoeta capoeta intermedia) در رودخانه شاپور (استان بوشهر)

Reproductive biology of Capoeta capoeta intermedia (Cyprinidae, Teleostei) in Shapour River (Bushehr province), Iran

به منظور مطالعه زيست شناسي توليدمثل سياه ماهي (Capoeta capoeta intermedia) رودخانه شاپور (استان بوشهر) تعداد 330 قطعه سياه ماهي به صورت ماهيانه طي آذر ماه 1391 تا آذر ماه 1392 از اين رودخانه صيد و مورد بررسي قرار گرفت. نسبت جنسي نمونه هاي صيد شده 1/6:1 (ماده به نر) و طول كل ماده ها از 15 تا 29 سانتي متر (ميانگين 2/3±19/83)، گستره وزني آن ها از 36 تا 250 گرم (ميانگين 38±93/4 (و طول كل نرها از 15/5 تا 26 سانتي متر (ميانگين 2±19/85) و وزن آنها از 36 تا 183/27 گرم (ميانگين 25/9±87/24 (به دست آمد. رابطه طول- وزن براي ماهيان ماده W=0.018L2.83، ماهيان نر W=0.075L2.34 و براي كل ماهيان W=0.029L2.67 برآورد گرديد. ضريب چاقي براي ماهيان از 0/82 تا 1/53 متغير بود و ميانگين هم آوري مطلق و نسبي به ترتيب 2252/63 و 22/08 عدد تخمك محاسبه گرديد. نتايج اين بررسي نشان داد هماوري مطلق همبستگي مثبتي با وزن سياه ماهي دارد. با توجه به نتايج شاخص رسيدگي جنسي (GSI) مي توان گفت دوره توليد مثلي اين ماهي از اسفند تا تيره ماه مي باشد.

Reproductive biology of Siah mahi, Capoeta capoeta intermedia was studied by examining 330 individuals collected between November 2012 to October 2013, by regular monthly collections in the Shapour River, Iran. Overall female-male (F-M) sex ratio was 1:1.66 and their total length (TL) was 15 to 29 cm (19.83 ± 2.3) and 15.5 to 26 (19.85 ± 2) cm for females and males, respectively. The minimum and maximum weight of female and male calculated 36 to 250 g (93.4 ± 38) and 36 to 183.27 gr (87.24 ± 25.9), respectively. Reproductive period for this species is from February to June when GSI is considerably higher than the rest months. The absolute fecundity (AF) of Capoeta capoeta ranged from 105 to 8134 eggs per fish, with mean AF value of 2252.6±310 eggs per fish, varying considerably at given length and weight and there was a positive linear correlation between AF with total weight (p<0.05). According to gonadosomatic index (GSI), the reproductive period for this species in this river was from February to June when GSI was considerably higher than the rest months.