Marzieh kaviani - Department of Marine biology, Faculti of Science, Islamic Azad University, Lahijan, Iran
Mohammad Reza Rahimibashar - Department of Marine biology, Faculti of Science, Islamic Azad University, Lahijan, Iran

European pond turtle, Emys orbicularis, the Emydidae family, is one of two species of fresh water turtles in the southern coast of the Caspian Sea and the Anzali Lagoon that has a very important ecological role inthe food web of this lagoon. Hence, in order to clarify the biological and morphometric characteristics ofthis species in this study, 249 specimens of European pond turtle were collected from Anzali lagoon, four sampling stations, by hand or fishing net from September to Novamber 2013 and April to August 2014. The specimen were numbered, weighed by a digital scale, and their morphometric characteristics weredetermined by a caliper precision of 0.05 mm accuracy. The average weights of male and female turtleswere 272.0±4.8gr and 447.0±9.8gr, respectively. And the average carapace length (SCL) for male and female turtles 123.0±0.70 mm and 139.0±1.0mm , respectively.The findings indicate that the sex ratio of male to female is 1 to 1.03, and morphometric characteristics infemales (SCL, CW, PL, PW, SH and BW) are larger than those of males. The comparison of TL (Total taillength) and CT (Cloaca-tail tip length) in the European pond turtle represents the difference between the position of the anus in both sexes , and its application to the determination of sex in this species.