Background: Pleistocene climatic oscillations and historical geological events may both influence current patterns of genetic variation, and the species in southern China that faced unique climatic and topographical events have complex evolutionary histories. However, the relative contributions of climatic oscillations and geographical events to the genetic variation of these species remain undetermined. To investigate patterns of genetic variation and to test the hypotheses about the factors that shaped the distribution of this genetic variation in species of southern China, mitochondrial genes (cytochrome b and NADH dehydrogenase subunit 2) and nine microsatellite loci of the Omei tree frog (Rhacophorus omeimontis) were amplified in this study.Results: The genetic diversity in the populations ofR. omeimontiswas high. The phylogenetic trees reconstructed from the mitochondrial DNA (mtDNA) haplotypes and the Bayesian genetic clustering analysis based on microsatellite data both revealed that all populations were divided into three lineages (SC, HG and YN). The two most recent splitting events among the lineages coincided with recent geological events (including the intense uplift of the Qinghai-Tibet Plateau, QTP and the subsequent movements of the Yun-Gui Plateau, YGP) and the Pleistocene glaciations. Significant expansion signals were not detected in mismatch analyses or neutrality tests. And the effective population size of each lineage was stable during the Pleistocene.Conclusions: Based on the results of this study, complex geological events (the recent dramatic uplift of the QTP and the subsequent movements of the YGP) and the Pleistocene glaciations were apparent drivers of the rapid divergence of theR. omeimontislineages. Each diverged lineages survivedin situwith limited gene exchanges, and the stable demographics of lineages indicate that the Pleistocene climatic oscillations were inconsequential for this species. The analysis of genetic variation in populations ofR. omeimontiscontributes to the understanding of the effects of changes in climate and of geographical events on the dynamic development of contemporary patterns of genetic variation in the species of southern China.

Background: Predicting invasiveness requires an understanding of the propensity of a given species to thrive in areas with novel ecological challenges. Evaluation of realized niche shift of an invasive species in its invasive range, detecting the main drivers of the realized niche shift, and predicting the potential distribution of the species can provide important information for the management of populations of invasive species and the conservation of biodiversity. The Australian redback spider, Latrodectus hasselti, is a widow spider that is native to Australia and established in Japan, New Zealand, and Southeast Asia. We used ecological niche models and ordinal comparisons in an integrative method to compare the realized niches of native and invasive populations of this spider species. We also assessed the impact of several climatic predictor variables and human activity on this niche shift. We hypothesized that human impact is important for successful establishment of this anthropophilic species, and that climatic predictor variables may determine suitable habitat and thus predict invasive ranges. Results: Our models showed that L. hasselti distributions are positively influenced by human impact in both of the native and invasive ranges. Maximum temperature was the most important climatic variable in predictions of the distribution of native populations, while precipitation seasonality was the most important in predictions of invasive populations. The realized niche of L. hasselti in its invasive range differed from that in its native range, indicating possible realized niche shift. Conclusions: We infer that a preference for human-disturbed environments may underlie invasion and establishment in this spider species, as anthropogenic habitat modifications could provide shelters from unsuitable climatic conditions and extreme climatic stresses to the spiders. Because Australia and the countries in which the species is invasive have differing climates, differences in the availability of certain climatic conditions could have played a role in the realized niche shift of L. hasselti.

Background: Predicting invasiveness requires understanding the propensity of a given species to thrive in areas with novel ecological challenges. The Australian redback spider, Latrodectus hasselti, a widow spider native to Australia and established in Japan, New Zealand, and Southeast Asia. We hypothesized that human impact is important for successful establishment of this anthropophilic species, and that climate factors may determine suitable habitat and thus predict invasive ranges.Results: We used ecological niche models to predict the potential distributions of this invasive species and to infer variables most important for population persistence by relating species observations to climatic variables and measures of human impact. We found L. hasselti distributions are positively influenced by human impact, particularly in the native range. Native distributions were most strongly predicted by maximum temperature and invasive distributions by precipitation seasonality.Conclusions: A strong climatic niche shift was detected in invasive populations compared to the natives. We infer that a preference for human-disturbed environments may underlie invasion and establishment in this species.

Effective recognition of potential threats is crucial for survival in aquatic habitats, especially for amphibian larvae. As a critically endangered species, understanding how the Chinhai spiny newt (Echinotriton chinhaiensis) larvae recognize novel predators provides key scientific support for developing targeted conservation strategies. Using the American bullfrog (Lithobates catesbeiana) as a representative predator, we examined larval responses by presenting isolated visual or chemical cues, as well as visual cues from predators of differing body sizes. We measured larval avoidance and activity. Results showed that with only visual cues, larvae quickly avoided the bullfrog and significantly reduced their activity compared to controls. With only chemical cues, activity decreased significantly, but avoidance behavior did not. When both large and small bullfrogs were present, larvae avoided the larger individual significantly more. These findings demonstrate that E. chinhaiensis larvae can use visual or chemical cues to detect novel potential predators and assess risk based on size to guide their avoidance behavior. This study provides key empirical data for understanding anti-predator responses in endangered caudate amphibians and informs conservation strategies against potential threats.

Background: Parental effects link parental phenotype and environmental variation to offspring performance and evolutionary trajectories. However, their role remains poorly resolved in species lacking post-oviposition care, where offspring development is shaped mainly by pre-hatching parental influences. We investigated how parental phenotype, reproductive investment, and parental relatedness were associated with offspring development in the Asiatic toad ( Bufo gargarizans ). Amplectant pairs were collected from the wild, and offspring were reared under standardized laboratory conditions from fertilization to metamorphosis. Parental relatedness was estimated using microsatellite markers to evaluate how parental genetic similarity was associated with offspring developmental and morphological traits. Results: We detected positive assortative pairing by body mass in B. gargarizans and strong clutch effects across offspring developmental traits, indicating substantial among-family variation. After distinguishing among parental body size, body mass, and body condition, the most consistent associations involved paternal body condition, paternal investment, and parental relatedness. Paternal body condition was positively associated with offspring growth rate during the G25-G42 interval, suggesting faster mid-stage larval growth in offspring of males in better condition. Paternal reproductive investment was positively associated with post-metamorphic morphology, particularly tibiofibula length at G46. Parental relatedness was negatively associated with length-related morphology around metamorphosis, and this association varied among developmental stages. Maternal traits showed more limited and mainly stage-dependent associations with offspring traits. Conclusions: Our results show that offspring development in B. gargarizans is associated with parental phenotype, reproductive investment, and parental relatedness. Paternal body condition and paternal investment were associated with offspring growth and post-metamorphic morphology, whereas parental relatedness was negatively associated with length-related morphology around metamorphosis. These findings suggest that parental effects in this species are trait-specific and stage-dependent. They also highlight the importance of integrating paternal phenotype and parental relatedness into studies of amphibian reproductive ecology, especially in species without post-oviposition care.