摘要: Understanding the ecogeographic mechanisms driving morphological variation is pivotal in biogeographic studies. However, patterns and determinants of such variation remain contentious, particularly in amphibians. Although several hypotheses have been formulated and investigated in amphibians, their validity remains disputed with mixed support. Using the Sichuan spiny frog(Nanorana sichuanensis) as an indicator, we investigated the morphological variations across geographic and environmental gradients to explore the underlying ecogeographic mechanisms. We found that both the body size and limb characteristics of N.sichuanensis were not significantly related to latitude or elevation, suggesting that it did not follow Bergmann's or Allen's rules. Eye diameter decreased linearly with increasing elevation and latitude, whereas snout length increased with increasing elevation and latitude. Heat balance, endurance, seasonality, water availability, and primary productivity collectively explain body size variation. Hierarchical partitioning identified primary productivity and thermal excursion as the most influential factors, explaining significant variability in body size and other morphological features. Specifically, primary productivity accounted for 52.40% of the variation in body size, whereas thermal excursion had the greatest impact on eye diameter(36.23%) and snout length(72.17%). Based on body size and dimensionally reduced morphological features, our results identified ecogeographic patterns, assessed the validity of different hypotheses, and examined how environmental factors influence these morphological variations. More generally, our study offers comprehensive insights into the ecogeographic variation observed in mountain amphibians,provides a critical evaluation of existing ecogeographic hypotheses, and infers possible morphological adaptations in response to environmental change.

摘要: Roadkill has become a pivotal issue in the global decline of amphibian populations.Conventional research methods have typically relied on the examination of dried carcasses found long after wildlife-vehicle collisions, which influnce the accuracy of the taxonomic classification and assessment of roadkill rates. To overcome these limitations, we conducted a nocturnal survey on National Road G108in the Qinling Mountains immediately following a night rainstorm in July 2016. We employed molecular techniques to distinguish species that are morphologically identical but share overlapping habitats. Our investigation revealed that within five hours, 92 amphibians from five different species were documented across three 2-km road transects. Among these, 31 individuals were identified as roadkill,resulting in an overall rate of 33%, or roughly five fatalities per kilometer. Significantly, the mountain stream frogs Nanorana quadranus and N. taihangnica comprised 40.2% and 30.4% of the total individuals observed, with mortality rates of 35.1% and 25.0%,respectively. We found no significant variation in mortality rates between different age groups or genders for either species. Our research suggests that conducting surveys at night, immediately following summer rainstorms, is an efficient strategy for evaluating the impacts of roadkill. The post-rain foraging behaviors and the dispersal of juveniles are key factors contributing to road crossings outside of the breeding season. Consequently, this study recommends that traffic authorities in mountainous areas take measures to reduce vehicle traffic following summer rainstorms in order to minimize the threat to amphibian lives.

摘要: Bufotes taxkorensis and B. zamdaensis are toads endemic to China. Both species inhabit highelevation and saline environments, and so provide a unique opportunity to investigate the adaptive responses of amphibians to extreme habitats. In the present study, we first observed and measured the histological structures of their skin and kidney in B.taxkorensis and B. zamdaensis. We then compared these results with similar findings for the low-elevation seawater dweller Fejervarya cancrivora and, finally,contrasted them with available data on species living in diverse habitats. Our results revealed the following adaptations:(1) In the Bufotes species, the epidermis and dermis both contain capillary vessels, facilitating blood-gas exchange and promoting adaptation to high-elevation hypoxia. The thick pigment layers present in the ventral skin of B. taxkorensis also help in adaptation to lower temperatures. In addition, the relative epidermis thickness of the dorsal and ventral skin is significantly greater in Bufotes species than in F.cancrivora, indicating adaptation to a terrestrial habitat.Comparing the terrestrial and semiaquatic species, we find that total dorsal and ventral thicknesses are both significantly greater in terrestrial than in semiaquatic species, helping to reduce water evaporation and damage from crawling, and thus promoting adaptation to terrestrial life.(2) The relative kidney filtration area of the Bufotes species is not significantly different from that of F. cancrivora, but accounts for only half that of terrestrial Bufo species. This lower total relative filtration area prevents excessive urea from being filtered out, avoiding excessive loss of body water and promoting adaptation to saline conditions. At the same time, the relative diameter of the proximal segment of Bufotes species is found to be similar to that of the semiaquatic F. cancrivora,facilitating the resorption of water and ions to increase plasma osmolality and promoting adaptation to saline environments. The findings of the present study offer insights into the adaptive mechanisms of amphibians in extreme environments and different habitats.

摘要: Despite continuous progress made on the taxonomy of the genus Tropidophorus, the Lao Water Skink, T. laotus, is only known from brief descriptions of its syntypes in historical literature. Here we designate a lectotype and paralectotype of the species, redescribe the species based on the type series and newly collected topotypes, provide the first colored photographs of taxonomically-verified individuals, and estimate its phylogenetic position using mitochondrial DNA data for the first time.Using these comparable data, we confirm that the previously identified “T. berdmorei” population from southern Yunnan Province, China, represents a distinct new species that is closely related and morphologically similar to T. laotus, but differs from true T. laotus by having considerable genetic divergence(4.7%–4.8% for 12S, 3.2%–4.2% for 16S)and distinct morphological characters(e.g., undivided frontonasal scales and a distinct color pattern of the throat). The southern Yunnan population is therefore described as a new species. With the above newly acquired data, we update the checklist and the provincial-level distribution of the genus Tropidophorus in China and compile an updated key to all recognized species of the genus from China and Indochina.

摘要: Here, we described Gekko(Japonigekko)ichangensis sp. nov., a new member of the genus Gekko Laurenti, 1768, based on specimens collected from Changyang Tujia Autonomous County, Yichang City, Hubei Province, China. Morphological comparisons and phylogenetic analyses using mitochondrial cytb and 16S genes place the new species within the subgenus Japonigekko, clustering with G.(J.) wenxianensis. The new species differs from other Japonigekko congeners by the following set of characteristics:(1) moderate body size(snout-vent length 58.5–66.5 mm in adult individuals);(2) nostrils touching the rostral, with 1–2 internasals present;(3)tubercles distributed on the head, dorsum, limbs, and tail, excluding the upper forelimbs;(4) 174–195ventral scales spanning from the mental to the cloacal slit;(5) 39–47 rows of ventral scales;(6) 12–15 subdigital lamellae under the first toes and 13–18under the fourth toes;(7) weakly developed webbing;(8) 5–8 precloacal pores in males;(9) three unilateral postcloacal tubercles;(10) a brown dorsum with six broad, irregular dark-brown bands extending from the nape to the sacrum. The identification of this new species raises the number of described Gekko species to 90. In China, 25 species are recorded, 21 of which belong to the subgenus Japonigekko.

摘要: Dear Editor,The true frogs classified under the genus Rana, with widespread distribution in Eurasia and North America,constitute a varied and intricate group (Yuan et al., 2016;Chen et al., 2022). In total, 52 species within this genus have been documented (IUCN, 2024), with 28 of those species found in China (Amphibia China, 2024).