Intraspecific variation in Pelophylax ridibunda (Rana ridibunda) in Southern Iran: life history and developmental patterns

This study describes the influences of variations in life history traits and developmental patterns of Pelophylax ridibunda. The causes of this variation were investigated by comparing observed patterns of interpopulational differences from geographic variables. The aim of the study was to investigate whether embryos and larvae from different populations of P. ridibunda show the same pattern of development when they are reared in the same conditions in the laboratory and to find out further whether if any differences appearing in the pattern among populations is environmentaly or geneticaly based. Egg masses of P. ridibunda were collected from four sites in Fars Province, Iran and reared in the same conditions. Samples from most of the developmental stages were fixed and clutch parameters were measured at early developmental stages. Morphological characters in embryos and larvae including egg diameter, growing size of embryos and larvae at different stages, external gill, cement gland and mouth parts structures were examined with light and scanning electron microscopy. Statistical analysis showed that the mean diameter of eggs and jelly coats were significantly different (p