The Ratio of Flesh to Body and Analysis on Biochemical Composition of Muscle in Pachyhynobius Shangchengensis

[Objective] The ratio of flesh content and biochemical compositions in muscles of Pachyhynobius shangchengensis were researched in this experiment to provide basic referrences for studying nutritive physiological ecology of Pachyhynobius shangchengensis. [Method] The biochemical analytic method was used to detect the ratio of flesh content and biochemical compositions in muscle of Pachyhynobius shangchengensis. [Result] The ratio of flesh contents of female and male Pachyhynobius shangchengensis were 54.93% and 55.84% respectively. The contents of protein, total saccharides and fatty acid of female Pachyhynobius shangchengensis were 15.44% ,1.70% and 0.68% respectively,while the same contents of male Pachyhynobius shangchengensis were 15.67%, 1.89% and 0.53% respectively. The total content of 18 kinds of amino acids was 12.72% （the proportion in fresh weight）, among which the content of 8 kinds of essential amino acids was 4.68%. The essential amino acids index（EAAI） was 72.68 and limiting amino acids was valine. There were 11 kinds of fatty acids in muscles of Pachyhynobius shangchengensis, among which the content of unsaturated fatty acids （80.02%） was higher than that of saturated fatty acids（ 19.98% ）. [ Conclusion] Pachyhynobius shangchengensis was a kind of valuable natural resource belonging to the nutritious type of low fat content and high protein content.

Reproduction,Development,and Growth Response to Captive Diets in the Shangcheng Stout Salamander,Pachyhynobius shangchengensis(Amphibia,Urodela,Hynobiidae)

The Shangcheng stout salamander(Pachyhynobius shangchengensis) is a poorly known stream dwelling hynobiid salamander from China. We studied the reproduction, development and growth response of the salamander to different diets in captivity. Two females each produced two unique, striated egg sacs, with each containing 18 and 20, and 22 and 32 white eggs with an average diameter of 3.3 mm. Hatchlings(n = 27) had front- and hind-limb buds with interdigit membranes and a large yolk sac, and developed cornified finger and toe tips during further development. Metamorphosis occurred between d 441 and d 454 after hatching at an average total length of 94.8 mm(n = 21). These reproductive and developmental traits fit in well with the ancestral state reconstruction in hynobiids. If corrected for dry mass, feed conversion ratios obtained by feeding bloodworms(Chironomidae) to P. shangchengensis larvae and mealworms(Tenebrio molitor) to postmetamorphs, were very low(0.33 and 0.34 respectively), equaling a very high mass conversion efficiency.

The Impact of Stream Landscape on Genetic Structure and Dispersal Patterns in Stream Salamander(Pachyhynobius shangchengensis)

Compared with other terrestrial environments,the stream environment generally presents a linear spatial structure and relatively simple environment.In a stream landscape,the dispersal direction of stream-type organisms usually presents a linear structure along the stream,which results in the limited dispersal and the genetic differentiation of stream-type organisms across different stream sections.The Shangcheng Stout Salamander(Pachyhynobius shangchengensis)is a narrowly distributed stream salamander in Dabie Mountains of East China.In the present study,we tested for the impact of stream landscape(i.e.waterfalls and underground river)on genetic structure and dispersal pattern in P.shangchengensis based on 12 nuclear microsatellite loci from 195 individuals in 3 populations(A,B and C)from three closely connected sections within one stream.Genetic diversity results suggested that Population B contains relatively high genetic diversity for P.shangchengensis when compared to the other populations(A and C).Detectable genetic differentiation was found(FST=0.008,P=0.007)among three populations,which was also supported by the Structure,FCA analysis and relatedness estimates of each pair of individuals among populations.The assignment test suggested that P.shangchengensis has philopatric males and female-biased dispersal(mean female Alc=.0.031,SE=0.225;mean male Alc=0.026,SE=0.198).Female-biased dispersal was also supported by analyses for each sex(i.e.Spatial autocorrelation,Genetic distance,Relatedness analysis).Our study indicated that small and isolated populations(A and C)had relatively low genetic diversity due to the limited population size.For stream salamanders,landscape features(i.e.waterfalls and underground river)can influence the ability of an individual to disperse through the landscape,and consequently influence the formation of strong genetic differentiation of P.shangchengensis.