Bangladesh J. Environ. Sci. Vol. 22, 38-41, 2012 @ BAED ISSN 1561-9206 TAXONOMIC STUDY OF SOME COMMON RANIDS OF BANGLADESH M.M. Rahman, M. M. Kabir and J.K. Biswas 1 Dept. of Zoology, Jahangirnagar University, Savar, Dhaka 1 Dept. of Zoology, Chittagong University, Chittagong ABSTRACT A research work was conducted during the period of March to December 2008 to observe the taxonomic parameters of some selected common ranids of Bangladesh. . The specimens were collected from different areas of the country. For convenience of observation only four species of the family Ranidae, i.e., Euphyctis cyanophlyctis, Fejervarya limnocharis, Hylarana typehensis and Hoplobatrachus tigerinus were studied. Tibio- tarsus articulation reached beyond the eye in F. limnocharis and H. tigerinus, in E. cyanophlyctis up to the eye and in H. typehensis up to the nostril. Pupil was rounded in all but semicircle in H. typehensis; tongue was pyriform in E. cyanophlyctis and H. tigerinus but bifid at the tip in F. limnocharis and H. typehensis. Vomerine teeth were present and hind limbs were overlapped in all species. All the measured taxonomic parameters were positively co- related with snout to vent length. Key words: Ranids, Taxonomic parameters. Introduction Amphibians are a class of vertebrate animals including frogs, caecilians, and salamanders. They are characterized as non-amniote ectothermic tetrapods (Wikipedia, 2009). Scientists have named approximately 1.75 million species of living organisms (Groom et al. 2006).where approximately 0.5% of all animal species measuring 6347 species (AmphibiaWeb, 2011) belong to the class Amphibia. Amphibians appeared in the late Devonian Period, about 350 million years ago (Minelli, et. al., 1987). Many fossil ranids are known, including both extant and extinct species of Rana from the Tertiary and Quaternary in Europe and North America, and probable Ptychadena fossils from the Miocene of Morocco (Heying, 2003). They are important in nutrient cycling between fresh waters and upland terrestrial environments, as pond nutrients, incorporated into their larval structure, are transported to the land through dispersal and death of transformed individuals (Storer and Usinger, 1972). From the agricultural point of view they are often referred to as farmer’s Friend (Dutta and Mohanty, 1978). As the consumed foods of Amphibians are mostly of insects, so that they are very important of biological control of pests. On the other hand, hey are eaten by predators such as fishes, snakes, birds, mammals (Blaustein and Wake, 1995). Thus the amphibians play an important role to equilibrate the ecosystems. Moreover, Amphibian species or communities have been touted as useful indicators in many situations (Welsh and Ollivier 1998, Galatowitsch et al. 1999, Collins and Storfer 2003, Sheridan and Olson 2003, Hammer et al. 2004). Among the amphibian ones, the true frogs, family Ranidae, have the widest distribution of any frog family. They are abundant throughout most of the world, occurring on most continents except Antarctica. Typically, true frogs are smooth, moist-skinned frogs, with large, powerful legs and extensively webbed feet. The true frogs vary greatly in size, ranging from small—such as the Wood Frog (Rana sylvatica)—to the largest frog in the world, the Goliath frog (Conraua goliath) (Wikipedia, 2009). The members of this family having the features of toothed upper jaw; parotid glands are absent. Diapophyses of sacral vertebrae not but very slightly dilated (Boulenger, 1890).Ranids are Neobatrachians, but relationships among the families of these "advanced" frogs are almost wholly unresolved. Within the Neobatrachia, ranids are members of the superfamily Ranoidea, a clade of derived forms that likely loses its monophyly if Dendrobatidae is included. Family relationships among the ranoids are in a state of chaos, and should be considered unknown. The number of subfamilies described for Ranidae has fluctuated considerably over the years, coincident with new hypotheses of relationship (Heying, 2003). Hence it is very important to know the sharp differences among different taxonomic parameters to study a species thoroghly, to differentiate one species from others and to determine its original systematic position as well as to identify a new species. For convenience of observation only a few species were selected for study. Materials and Methods The research work was conducted at the laboratory of Department of Zoology, Jahangirnagar University during the period of March to December 2008. For this study the specimens were collected from the bank of ponds, lakes and other water bodies and from the wet-grassy area of various parts of Bangladesh.These were 38