Lotic specialization in modern Asian newts(Caudata:Salamandridae):Phylogeny,historical biogeography,and ancestral traits based on combined DNA data

Pachytriton,and Paramesotriton,are primarily distributed across East Asia,displaying a broad range of environmental adaptations,including generalists inhabiting both lotic and lentic habitats and lotic specializations.Despite recent studies on their biogeographic history,how these species adapted to geographical changes remains unclear.In this study,divergence times and reconstructed ancestral traits were estimated based on phylogenetic analysis of mitochondrial and nuclear DNA sequences,totaling 4048 bp.Results indicated that the divergence between lotic-specialized and generalist species occurred during the middle to late Miocene(95% confidence interval(CI):16-13 million years ago(Ma)),correlating with the long-lasting arid period(14-12 Ma)and uplift of the Wuyi-Nanling mountains(15-11 Ma).Ancestral trait reconstruction revealed notable morphological changes associated with the emergence of lotic-specialized lineages.Specifically,male body size increased from 130 mm to 140 mm,and epibranchial traits shifted from thin to thick structures.Additionally,variation in tongue movability and skin texture were observed among lotic species.Each morphological shift is hypothesized to have an ecological basis,facilitating adaptation to specific environmental conditions.Overall,this study represents the first comprehensive attempt to elucidate the evolution of ancestral traits among divergent species of modern Asian newts,providing a deeper understanding of their adaptive responses to historical geographical and climatic changes.

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.

Molecular Phylogeny and Evolution of Two Rhacophorus Species Endemic to Mainland Japan

We conducted molecular phylogenetic analyses of Japanese Rhacophorus species, especially of R. schlegelii and R. arboreus from the mainland, based on samples encompassing their known distribution ranges, and discussed about evolutionary history of Rhacophorus species within Japan. The common ancestor of Japanese Rhacophorus, except for R. owstoni from southern Ryukyus, was estimated to have diverged from a lineage occurring mainly in China about 7 MYBP. Both R. schlegelii and R. arboreus are genetically largely divergent between regions of eastern and western Japan, and this seems to have been promoted mainly by retreat to refugia. Retreats of the two species to different refugia sometimes in the past seem to have led restricted distribution of R. schlegelii in eastern and R. arboreus in western Japan, and brought their intraspecific variation patterns in morphology and breeding habit.

Phylogenetic placement and diet of homalopsid snake Miralia alternans (Ruess,1833)

DEAR EDITOR,Miralia alternans(Ruess,1833)is distributed in Borneo,Sumatra,and Java in Southeast Asia.The species is morphologically similar to Raclitia indica,a monotypic genus known from Peninsular Malaysia.Here,we collected a juvenile specimen of M.alternans from Borneo,and report on its coloration in life and first prey item recovered from the species.We also explored the phylogenetic position of the genus using molecular phylogenetic analysis of mitochondrial DNA(mtDNA)gene cytochrome b(cyt b)and nuclear gene prolactin receptor(PRLR),confirming M.alternans as sister to R.indica,with the two genera exhibiting relatively high genetic divergence in cyt b(13.0%-13.1%).