First study of age structure, growth pattern and reproductive age in populations of marsh frog (Pelophylax ridibundus) species in the northern and southern habitats of Khuzestan province

Skeletocronology is a reliable method for estimating the age but in amphibians little researches have been done in this field. In the present study, for the first time in the country of Iran, the age structure of the population, growth pattern and reproductive primary age were studied in the populations of marsh frog in the northern and southern regions of Khuzestan province. For this purpose, 20 female and male marsh frog samples were fished alive in the Khuzestan province and transferred to the laboratory. After biometric studies, the specimens were prepared and after the removal of the bones of the limbs, bone samples were passaged as routine histotechnique. The number of growth stop lines and samples age were determined. In order to determine the relationship between age and body weight, body length and age with eye lens weight, the data was analyzed statistically. the maximum number of loops counted in this population is . The adult age of males of northern and southern, males of the northern and males of the southern regions was determined 2,2 and 3 years respectively. with increasing age of females, the co-integration rate of females was reduced which is explainable by the reduction in bioavailability due to the increase in biological age. According to the results, there was a significant correlation between age of animals with body and  eye lens weight, but there was no significant correlation between age of  animals with body length, except a limited number of males in northern regions (P<0.05) There was.