Osteopathic Analysis Of Sexual Maturity, Growth And Longevity Of 10 Species Of Frogs

The age at sexual maturity,growth and life-span of ten Anura species were studied using the skeletochronological method.These frogs or toads include swelled vent frog(Feirana quadranus),Chinese brown frog(Rana chensinensis),mixtured pygmy frog(Microhyla mixture),Tsinling tree toad(Hyla tsinlingensis),black-spotted pond frog(Pelophylax nigromaculata),plateau frog(Nanorana pleskei),Siberian toad(Bufo radd-ei),Ningshan alpine toad(Scutiger ningshanensis),Zhoushan toad(Bufo gargarizans)and West China toad(Bufo andrewsi).Age was determined based on the numbers of lines of arrested growth(LAGs)on cross section of phalanges.Age pyramid was cons-tructed.The age at sexual maturity was determined when the space between two LAGs suddenly narrowed,implying that the growth rate decreases since more energy was assigned to reproduction.The age at sexual maturity represents the generation time.The growth curves of snout-vent length(SVL),head length(HL),head width(HW),length of lower arm and hand(LAHL),and hind limb length or leg length(HLL)were built with von Bertalanffy's growth equation.The K-values were used to calculate the growth rates of body length,head length,head width,fore arm and head,and hind legs in populations.The results are listed as below.The maximum longevity of female F.quadranus is 12 years,generation time is 5 years,while the maximum longevity of male is 9 years,and the generation time is 4 years,the age at sexual maturity is higher in female than in male;the Taibai population and the Liupanshan population of the Chinese forest frog have the same generation time and maximum longevity,the maximum of female R.chensinensis is 4 years,generation time is 3years,while the maximum longevity of male is 5 years,and the generation time is 2 years;the maximum longevity of female M.mixture is 5 years,generation time is 3 years,while the maxi-mum longevity of male the same as female,and the generation time is 2 years;the maximum longevity of female H.tsinlingensis is 4 years,generation time is 3 years,while the maximum longevity of male is 5 years,and the generation time is 2 years;the maximum longevity of female P.nigromaculata is 5 years,generation time is 3 years,while the maximum longevity of male is 3 years,and the generation time is 2 years;the maximum longevity of female N.pleskei is 2 years,while the maximum longevity of male is 5 years,and the generation time is 2 years;the maximum longevity of female B.raddei is 6 years,generation time is 3 years,while the maximum longevity of male is 5 years,and the generation time is 3 years;the maximum longevity of female B.gargarizans is 6 years,generation time is 3 years,while the maximum longevity of male is 5 years,and the generation time is 3 years;the maximum longevity of female B.andrewsi is 5 years,generation time is 3 years,while the maximum longevity of male is 4 years,and the generation time is 3 years;the maximum longevity of female is S.ningshanensis 10 years,generation time is 6 years,while the maximum longevity of male is 7 years,and the generation time is 6 years.Results from the studies further indicated that species with longer generation time has larger maximum life-span,growth coefficient of body of F.quadranus and R.chensinensis of the Liupanshan population was larger males than in females.The growth rate of body length of F.quadranus was lower in females than in males,while,the growth rate of body length of R.chensinensis was higher in females than in males.The growth coefficient of M.mixture,P.nigromaculata and N.pleskei was higher in females than in males and same as the average growth rate.The analyses of the growth curves indicated that the sequence of body length,head length,head width,forearm and hand length,and hind leg length was not in accordance with the sequence of their K-values,but consistent with their average growth rates.Differences of life history between the males and females caused the sexual dimorphism in F.quadranus,differences life history led the sexual dimorphism in Rana chensinensis,M.mixture and P.nigrormaculata.However,there was not sexual dimorphism in body length of N.pleskei and B.andrewsi.The phenomena of sexual dimorphism in B.raddei,S.ningshanensis and B.gargarizans was caused by sexual selection.