| Morphology is a special form of biological science. Morphological study helpspeople understand the species structure, distinguish differences of morphologicalcharacteristics between different species; it also reveals how morphological featuresare produced and evolved by studying and comparing morphological features indifferent ecological environments, thus describing the relationship betweenmorphological characteristics and ecological environment. So it has importanttheoretical and practical significane.Hynobilldae, endemic in Asia China, is considered to be a kind of extremely basalgroup in terricolous vertebrates. In this paper, Batrachuperus pinchonii, Liua shihi,Hynobius leechii, Salamandrella keyserlingii, Onychodactylus zhangyapingi,Pachyhynobius shangchengensis were taken as the research materials, the externalmorphological characteristics and skin tissue in these six species were researched notonly to determine the different morphological characters between intraspecific,interspecific and microstructure of skin tissue but also to further elaborate sexualdimorphim of six salamander and explain the relationship between externalmorphological characteristics and ecological environment, between skin tissuecharacteristics and ecological environment. This study can provide the basis data forthe study of functional morphology study.The results of the sexual dimorphim of six salamanders show that:(1) The snout-vent length (SVL) was not significantly different between the male and female inB.pinchonii (t=-1.881, df=50, p=0.066), and the sexual dimorphism mainly showed asfemales has larger values of space between axilla to groin (AGS) than males.(2) Thesnout-vent length (SVL) was significantly different between the male and female in L.shihi (t=7.696, df=257, p=0.000), and the sexual dimorphism mainly showed asfemales has higher values of head length (HL), head width (HW) than males, but themales has larger values of length of forelimb (FLL), forelimb width (FLW) and hindlimb width (HLW) than females.(3) The snout-vent length (SVL) was notsignificantly different between the male and female in H. leechii (t=-1.637, df=23,p=0.115), and the sexual dimorphism mainly showed as females has larger values ofhead length (HL),snout length (SL),diameter of eye (ED), interorbital space (IOS)than males, but the males has larger values of head height (HH), hindlimb width (HLW)than females.(4) The snout-vent length (SVL) was not significantly different betweenthe male and female in S. keyserlingii (t=-0.550), df=40, p=0.585), and the sexualdimorphism mainly showed as males has larger values of head width (HW), headheight (HH), tail length (TL), tail height (TH), length of forelimb (FLL), and length ofhindlimb (HLL) than females.(5) The snout-vent length (SVL) was significantlydifferent between the male and female in O. zhangyapingi (t=-3.843, df=15.414,p=0.002), and the sexual dimorphism mainly showed as females has larger values ofinternarial space (INS) than males.(6) The snout-vent length (SVL) was significantdifference between the male and female in P. shangchengensis(t=0.619, df=21,p=0.542), and the sexual dimorphism mainly showed as males has larger values ofhead height than females. The morphological features in six kinds of Hynobiidsanimals assuredly present sexual dimorphism. This may be mainly due to threeevolutionary hypotheses: sexual selection, fecundity selection and ecologicalenvironmental impact.The results of interspecific comparison of external morphological characterticsshowed that：(1) the SVL of aquatic salamander was significantly greater thanterrestrial salamander,(2) the head (head length, head width, head height) of aquaticsalamander was significantly greater than terrestrial salamander,(3) the tail length ofterrestrial salamander was significantly greater than the aquatic salamander, but the Lshihi except,(4) tail height, tail width, limbs between the terrestrial and aquaticsalamander had no obvious rules. The interspecific differences were separated by thedifferences between species niche and the food niche.The basic structures of skin in six different hynobiid species were similar, andconsisted of epidermis and dermis. The epidermis was made of stratum corneum,stratum interim and stratum basale, while the dermis consisted of stratum spongiosumand stratum compactum. The stratum spongiosum abounded in glands, which weredivided into two types: mucous glands and granular glands. However, the thickness ofstratum corneum and the distribution of capillaries, glands, and chromatophores weredifferent significantly in skins of six species. The basic structures of skins in six hynobiid species were similar, which was correspondent with their systematics status.The total thickness of six hynobiid species’ skin had significant difference but noregularity. However, the thickness percent of stratum spongiosum and stratumcompactum correspond with their habitat and evolutionary position. The stratumcorneum of B. pinchonii, L. shishi, P. shangchengensis, which are mainly aquatic, isthiner and have more capillaries in epidermis than terrestrial species. However, the H.leechii and S. keyserlingi, which are mainly terrestrial, have fewer capillaries inepidermis than B. pinchonii, L. shishi, P. shangchengensis, which are mainly aquatic,but the O. zhangyapingi, which mainly are terrestrial has no lungs, has a lot ofcapillaries in epidermis. Therefore, the skin morphological characteristics of sixhynobiid species correspond with their life habit, life history and evolutionary position. |
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