A preliminary study on the biology of Marsh frog (Pelophylax ridibundus) in Roudbar city, Guilan province

There are15 species of frogs and toads belonging to 8 genera and 5 families and 7 salamander species belonging to four genera and two families in Iran. This study was conducted on the Pelophylax ridibundus, is known as the Marsh frog. Specimens belonging to the Roudbar city (Guilan province) and collected by hand and net from April to November in 2013 and 23 morphometrical and some morphological characters were studied in the laboratory. Data were analyzed using SPSS (version 21), and T-test analysis. To evaluate the diet, specimens were dissected after being anesthetized and all the contents of its stomach fixed in 75% alcohol and animals that were not fully digested were initial identification. The results of 65 specimens (42 females, 7 males and 16 juveniles) showed that this species has a dorsal surface to olive green in color with separate dark spots that spots are rarely in the hands. Ventral surface is white and contains several black spots that these spots are seen only in some specimens and indicating the presence of polymorphisms in the studied specimens. It was identified a number of aquatic snails, grasshoppers, spiders, beetles, ladybird, bees and ants in the contents of the stomach and intestine of this species and were identified at the family level. Males have resonators in posterior end of the mouth and on the posterior part of the tympanic membrane and callosity on the first finger. The most frequency body length (L), (61.31%) at a distance of 70-60 mm in males and of females (52.17 %) at a distance of 50-40 mm. The sex ratio of male to female was 1 to 6 in this study. It was observed significant difference in L.tym (length of tympanum) and C.int (internal metatarsal tubercle) between sexes in the level of 0.05 and did not find significant difference in the other characters.