Scale deformities in three species of the genus Garra (Actinopterygii: Cyprinidae)

Different types of scale deformities have been reported from fishes worldwide, however there is no available study on the abnormal scales in the genus Garra except for G. variabilis. In the present study, scale deformities of three species of Garra including G. rufa, G. persica and Garra sp. from 6 sites of the Iranian drainages were examined and described. Different deformations were observed in focus, anterior, posterior and lateral sides of scales in the studied species, showing both slight and severe abnormalities. The occurrence of twin scales was one of the most interesting cases among various types of scale deformities observed on G. persica and Garra sp. Genetic disorders, diseases (including infection and lesions), developmental anomalies, incomplete regeneration after wounding, physical, and chemical environmental variables including pollutions might be considered as potential factors for scale abnormalities remained to be investigated.