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

Abstract

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 total 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.