observation and studying the morphometerical characteristics in euphrates turtle

The euphrates turtle, rafetus euphraticus, is one of the least known aquatic species inhabited in northwest of persian gulf and khuzestan province waters. to evaluate the morphometerical and biological characteristics of this species, 32 samples were captured from nearby populations of khuzestan province through balarood, sakhiri, dez, gargar and shatit rivers and the lagoons of shadegan and hooralazim of which 14 samples were used for morphometerical tests. the measured characteristics were sex determination, carapace curved length and width, plastron length and width, the length of cloaca, the length of tail, total weight, the ratio of plastron length/width, carapace length/width, plastron length/carapace length and cloaca length/plastron length. the maximum weight of the collected specimens was up to 20 kg and the sex ratio (males to females) was 1:0.7. highly significant correlation was found between sex and some morphometerical characteristics such the ratio of carapace length/width which would be considered as an index in the situation that cloaca observation is impossible. more morphological and ecological studies are needed for better understanding about the species in iran.