Studies On The Ecological Adaptability Of Odorrana

Odorrana margaretae,O.graminea and O.schmackeri are belong to genus Odorrana of Ranidae,Anura,Amphiba,and represent 3 species groups,namely,Odorrana margaretae group O.graminea group and O.schmackeri group,among which,O.margaretae is the type species of genus Odorrana.In this thesis,we studied and compared their osteological characteristics,aiming to provided osteological evidence for taxonomy,to discuss the relationship between the osteological morphology and the function,and to explore the adaptive traits of osteology of the Odorrana frogs.All specimens were adults and collected from their type locality.We dissected the frogs using conventional methods,and photographs were taken using a Nikon D7100 camera.The main results are shown in the following:(1)The main osteological characteristics of the Odorrana frogsThe nasals are separated from one another medially,and are not in contact with the frontoparietals posteriorly.The sphenethmoid is visible in the dorsal view.The premaxillae and the maxillae bear numerous aligned teeth.The vomers are well developed.The centrum is diplasiocoelous.The episternum has an umbrella-like shape;the posterior end of the omosternum is fan-shaped,and distinctly broader than the anterior end;the mesosternum is dumbbell-shaped,longer than the omosternum,and the anterior margin of the mesosternum is broader than the posterior end;the xiphisternum is W-shaped and bears a deep incision posteriorly.The pectoral girdle is firmisternal.The prepollex of the male is well ossified.The tibiofibula is distinctly longer than the femur.The distal tips of the terminal phalanges exhibit an anchor-like shape.(2)The interspecific distinctions of osteology of the genus OdorranaFor Odorrana margaretae,the anterior part of the nasal is fan-shaped,and the angle between the later margin of the nasals and horizontal line is 47�,while the anterior portion of the nasal of O.graminea is roughly triangular,and that of O.schmackeri is quadrangular,and their nasals are slanted 53�,54� respectively.The anterior part of O.margaretae is oval-shaped,the anterior part of O.graminea is concave,and that of O.schmackeri is horizontal and straight.The anterior processes of O.margaretae and O.graminea are distinctly longer than the prechoanal processes,whereas those of O.schmackeri is opposite.For O.margaretae and O.graminea,the length of the hyoid plates is greater than its least width.,however,the hyoid plate of O.schmackeri is broader than long.Additionally,the clavicles of O.margaretae are medially straight,those of O.graminea are slightly inclined anteriorly,interestingly,the clavicles of O.schmackeri are curved posteriorly.(3)Sexual dimorphism in the forelimb of the Odorrana frogsCompared with the female,the humerus of the male O.margaretae bears more robust crista medialis and crista ventralis.The crista medialis,crista lateralis and crista ventralis of the humerus of male O.schmackeri are distinctly larger than those of the female.Moreover,for the male Odorrana frogs,the prepollex are well ossified,and much larger.Conclusions:(1)The osteological characteristics of the Columellae of the Odorrana frogs are more effectively to transmit the sound waves,and thus enhance the sensitivity of hearing,which is adapt to the stream dwelling.(2)The ilio-sacral articulation belong to sagittal-hinge morphs,and the tibiofibula is longer than the femur,which means the Odorrana frogs have a better ability of jumping and swimming.(3)The distal tips of the terminal phalanges of the Odorrana frogs end in an anchor-like shape,their toe pads are larger,and therefore have stronger adhesion.(4)Larger crests on the male humerus could potentially increase the surface of the humerus and accordingly allow for the attachment of more musculature,which is most likely correlated to amplexus.