Review of population structure factors of Capoeta trutta in Gamasyab River at the Hamedan province

Capoeta trutta living in the Middle East and Iran in the catchment Region of the Tigris and Forat and Karun shoot lives. Samples caught by electric fishing two stations using this species as season of the from Jun 2011 to August 2011 the kharchangrod and Cheshmemahi Gamasyab River the province. Within a year the total number of samples, 224 fish were caught and analyzed. Overall, average total length of the two stations 13.22 ± 5.06 cm and 34.44 ± 30.08 g total weight is 17.37 ± 2.84 and 12.48 ± 5.02 cm and average weight of kharchangrod in the stations, and Cheshmemahi, respectively, is 61.67± 28.81 and 29.56 ±27.56 g. Both two stations fish were caught with five groups +0 to +4 are the age group+1 is dominant. The logarithmic relationship between length and weight of kharchangrod and Cheshmemahi sampling stations, respectively, W= 2.85 TL- 4.09 and W=2.94 TL- 4.4 the growth pattern of fish in both stations is negative allometric. Kharchangrod growth equation parameters Brtalanfy station is L ∞= 204.151, k= 0.56 and t. = - 1.68 and Cheshmemahi station is L ∞= 211.489, k= 0.59, t. = - 0.74.