Survey of some aspects of the reproductive biology Siah Mahi (Capoeta capoeta gracilis) In Babol River

This research was carried out on Capoeta capoeta gracilis, from August 2010 to July 2011.in the Babolrood river of Mazandaran province. The sampling was done monthly and samples were collected by Electroshoker. In total 224 numbers of this kind were caught. Total length,forka length, standard length, body weight, age, sex, gonad weight, and ovum diameter were measured and recorded. Fish scales were used for the determination of age. Total length mean was 146.29 Ml with the standard deviation of 22.79, and 130.76 with the standard deviation of 22.29 in the female and male sex respectively. Total weight mean was 42.63 with the standard deviation of 20.75, and 30.79 with the standard deviation of 16.56 in the female and male sex respectively. Samples belonged to the age groups (0, 1, 2, 3, 4). Most of them (%39.7) belonged to the age group (3). Ovum diameter mean was 0.76 mm with the standard deviation of 0.57in tajan river, were 3603 and 65.56 with the standard deviation of 2796 and 36.7 respectively. The GSI mean was %3.1 with the standard deviation of 3.53, and %3.29 with the standard deviation of 7.21 in the female and male sex respectively. The mean of fatness coefficient or quantity coefficient or CF value was 1.26 with the standard deviation of 0.11, and 1.33 with the standard deviation of 0.91 in the female and male sex respectively.