Reproductive biology and age determination of Garra rufa Heckel, 1843 (Actinopterygii: Cyprinidae) in central Iran

Some aspects of the reproductive biology of Garra rufa Heckel, 1843, a native cyprinid fish species from the Armand stream in Chaharmahal-o-Bakhtiari province, central Iran, were investigated by regular monthly collections throughout 1 year. A significant relationship between length and weight and the isometric growth pattern were observed in this fish. There were no significant differences in the tota l number of male and female specimens. The population of this cyprinid fish had a narrow age range of 0-4 years, and the maximum number of samples belonged to the age group of 2.01-3 years. Based on the patterns of gonadosomatic and Dobriyal indices, it was concluded that this fish population has a prolonged, active reproductive period, which is a type of adaptation by this population to environmental conditions. The average egg diameter was 0.67 mm; the highest diameters were seen in May and the lowest in November. The absolute and relative fecundity were 1179.6 and 109.4, respectively. There was a significant relationship between fecundity and fish size (total length and total weight), and also between absolute fecundity and gonad weight.