a study on populations of endangered species, shemaya, chalcalburnus chalcoides in the haraz and shirud rivers

in this study, age and growth for two populations of shemaya, chalcalburnus chalcoides, in haraz and shirud rivers were investigated from april to june 2006. 704 fish specimens were collected using a cast- net. the maximum length and weight in a 5- year old female observed were 251 mm and 96 gr, respectively. the most abundant age groups were 2+ and 3+ years for male and female respectively. while male of shirud populations were heavier and longer on average in younger ages (ancova, p ? 0.05), differences in female were not significant (ancova, p? 0.05). female of haraz population had isometric growth while positive allometry was observed in the fish population of shirud. the von bertalanffy growth parameters were: (haraz population: for male and for female), (shirud population: for male and for female). in the two populations, female had higher l?, while k value for males was relatively higher in the two rivers.