Industrial activity, dam construction, and agriculture—while important for socioeconomic progress—can severely damage the natural environment. To evaluate the effects of these human activities on the bio-integrity of riverine ecosystems, we examined the Wanan reach of the Ganjiang River (Wanan River basin), which contains the river’s largest reservoir. On the basis of 20 attributes of zooplankton, we constructed a zooplankton index of bio-integrity (Z-IBI) evaluation system using range analysis, discriminant analysis, and correlation analysis. Our research found that these anthropogenic activities can greatly change the composition and number of zooplankton community. The overall health status of this catchment was classified as “good”, and the eco-health situation of the reference, industrial, dam-controlled and agricultural sites were deemed “healthy”, “fair”, “good”, and “fair”, respectively. Our results suggested that the three activities adversely affected the integrity of local aquatic ecosystems. Agriculture was the activity most detrimental to the zooplankton community, followed by industrial production and dam construction. Therefore, we demonstrated that the Z-IBI evaluation system can be applied to reservoir–riverine ecosystems. We also provide guidance on the ecological protection, assessment, monitoring and of reservoir–riverine ecosystems and suggest that additional Z-IBI evaluation approaches be further developed in the future.

Bisphenol A (BPA) is an endocrine-disrupting compound, and the binding mechanism of BPA with carrier proteins has drawn widespread attention. Halogen substitutions can significantly impact the properties of BPA, resulting in various effects for human health. Here, we selected tetrabromobisphenol A (TBBPA) and tetrachlorobisphenol A (TCBPA) to investigate the interaction between different halogen-substituted BPAs and human serum albumin (HSA). TBBPA/TCBPA spontaneously occupied site I and formed stable binary complexes with HSA. Compared to TCBPA, TBBPA has higher binding affinity to HSA. The effect of different halogen substituents on the negatively charged surface area of BPA was an important reason for the higher binding affinity of TBBPA to HSA compared to TCBPA. Hydrogen bonds and van der Waals forces were crucial in the TCBPA–HSA complex, while the main driving factor for the formation of the TBBPA–HSA complex was hydrophobic interactions. Moreover, the presence of TBBPA/TCBPA changed the secondary structure of HSA. Amino acid residues such as Lys199, Lys195, Phe211, Arg218, His242, Leu481, and Trp214 were found to play crucial roles in the binding process between BPA compounds and HSA. Furthermore, the presence of halogen substituents facilitated the binding of BPA compounds with HSA.

Seasonal shifts in hydrology are known to alter the abundance and diversity of basal production resources and habitats and hence strongly influence the structure and function of river ecosystems. However, equivalent knowledge of natural lake ecosystems in floodplain regions is lacking. Here, we used stable isotope ratios of carbon and nitrogen to assess available primary production sources and consumer taxa during the dry and wet seasons in a large floodplain lake connected to the Yangtze River. Fish species showed distinct δ¹³C values between two hydrological periods but only small changes in δ¹⁵N values. Most of the fish species had higher estimated trophic levels in the dry season, likely indicating greater carnivory. Results of Bayesian mixing models revealed that benthic algae and benthic organic matter (BOM), combined with C₃ vegetation, were the principal food sources supporting the biomass of most fish species during the low-water period, whereas benthic algae and seston were the most important carbon sources during the flood period. Overall, these findings demonstrate that seasonal hydrological changes, such as water-level fluctuations, can affect the trophic structure and ecosystem functioning of floodplain lake food webs in the subtropical zone.

Understanding trophic interactions in food webs is crucial to revealing the transfer of substances and energy from primary food sources to consumers in aquatic ecosystems. We hypothesize that the trophic structure of consumers can be significantly affected by primary food sources (pelagic, benthic, and littoral sources) through complex trophic interactions. This study used stable isotope analysis and Bayesian mixing models to estimate the trophic levels of fish consumers and the contributions of primary food sources in the three sub-lakes (Eastern, Southern, and Western Dongting) of Lake Dongting, which have different physical and chemical parameters of water, fish species diversity, and plankton (phytoplankton and zooplankton) density. Results showed the differences in community structures of fish among sub-lakes. Fish trophic levels were significantly higher in Eastern Dongting than those in the two other areas. The contributions of primary food sources to fishes were as follows: the pelagic source was the main basal food source in Eastern Dongting, and littoral and pelagic sources played equally essential roles in Southern Dongting; fishes in Western Dongting relied on more benthic source to growth than those in the two other regions. This study can fill gaps in our knowledge of the influence of the underlying food available on trophic structure of consumers by exploring the role of primary food sources and making the trophic structure of consumers in the aquatic food web highly complicated and diverse through control of the distribution of primary food sources.

Background: Yangtze finless porpoise (YFP, Neophocaena asiaeorientalis), is the first class protected animal in China. In order to analyze the adaptive evolution of fecundity traits in YFP, the rapidly evolving gene families of YFP were obtained. At the same time, the major genes controlling ovulation, GDF9, BMP15, FSHβ and FSHR were also analyzed. Methods: Orthofinder software was employed to search homologous genes based on protein sequence. CAFÉ software was used to obtain the expansion and contraction gene families of YFP. Then, GO terms and pathway enrichment analyses were performed using TBtools software and Swissprot database. PAML package was used to calculate Ka/Ks (i.e., ω). Evolution rate changes in the positive selected genes were examined using the GU99 process in Diverge (v3.0) program. Result: In YFP, 501 rapid expansion gene families GO enrichment results showed that the reproductive activities related pathways were mainly three significant enrichment process, participation of germline stem cells maintain androgen receptors signaling pathways regulating and male reproductive tract stem cell population to maintain. The most significant GO terms of 220 rapidly contraction gene families associated with reproductive activities mainly consisted of biological processes which were involved in positive regulation of estrogen secretion, mating and estrogen metabolic process. GDF9 and BMP15 genes exhibited purifying selection. However, significant signs of positive selection were detected in FSHR and FSHβ genes, but only FSHβ showed specific changes in the YFP lineage.

The Rubiaceae family, the world’s fourth-largest angiosperm group, exhibits exceptional species and morphological diversity across its global distribution. Understanding its biogeographic patterns and their environmental drivers is critical for elucidating the evolution, ecological adaptation, and conservation priorities of this family. Here, we integrated global-scale distribution data with growth-form classifications (herbaceous vs. woody) to map the species richness patterns of Rubiaceae. We then related these patterns to four types of environmental variables (water and energy, climate seasonality, historical climate change, human influence) to identify key drivers of richness variations across growth forms. Our results indicated that the species richness pattern of Rubiaceae species exhibits significant spatial heterogeneity at the global scale. Total and woody species richness generally exhibit distinct latitudinal distribution patterns, peaking in tropical regions, whereas herbaceous plants predominate in mid-to-high latitudes. The drivers of these patterns also differ among growth forms. Actual evapotranspiration (AET) is the strongest predictor of species richness for the family as a whole and for different growth forms. Among the four types of environmental variables, water and energy are key factors driving the diversity pattern of total species of Rubiaceae. Environmental factors, especially water and energy, have a much stronger impact on the species richness patterns of woody plants than on those of herbaceous plants. These findings highlight the unique biogeographic patterns and potential environmental driving mechanisms of the diversity of Rubiaceae species, providing a theoretical basis for the diversity of global conservation in Rubiaceae.