Ecology and Evolution最新文献

Hyalomma rufipes is a widely distributed tick species and a competent vector of Crimean-Congo Hemorrhagic Fever Virus (CCHFV), a serious zoonotic pathogen endemic to over 30 countries. Despite the epidemiological importance of CCHFV and H. rufipes in East Africa, little is known about the genetic structure and movement of H. rufipes populations, limiting the understanding of CCHFV transmission dynamics in this region. This study developed and characterized 14 polymorphic microsatellite markers to support population genetic studies of H. rufipes. H. rufipes ticks were collected from livestock in Garissa and Isiolo counties in northern Kenya. Morphological identification was confirmed using 16S rRNA Sanger sequencing and phylogenetic analysis. Low-pass whole genome sequencing was performed on representative samples, and the Quality and Diversity of DNA (QDD) pipeline was used to identify and design microsatellite primers. Of 59,201 candidate loci, 30 were selected for initial screening; 14 loci consistently amplified and were polymorphic. These included mostly tetranucleotide repeats and showed high allelic richness and gene diversity. Several loci showed signs of null alleles, but no evidence of stuttering or allelic dropout was found. These newly developed microsatellite markers provide a valuable tool for investigating H. rufipes population dynamics and dispersal, with the ultimate goal of understanding CCHFV transmission dynamics in East Africa.

Miridae is the most species-rich family of true bugs and plays an important role in both natural and agricultural ecosystems. However, contemporary controversies surrounding their phylogenetic relationships and subfamily classification still lack consensus. This study employs molecular systematics to resolve Miridae phylogeny, utilizing mitochondrial genomes from 42 species spanning 39 genera across six of the seven currently recognized subfamilies. Four outgroup species from Tingidae (2 species) and Thaumastocoridae (2 species) were also included in the analyses. Our results demonstrate that: (1) Bryocorinae is paraphyletic as the stem groups of Miridae; and (2) the clade ((Deraeocorinae + Mirinae) + (Orthotylinae + Phylinae)) is consistently and strongly supported as a monophyletic group across all datasets and analytical methods. We report newly sequenced mitochondrial genomes based on high-throughput sequencing platforms for four Miridae genera and species: Chlamydatus sp. (Phylinae), Deraeocoris punctulatus (Deraeocorinae), Scirtetellus sp. (Orthotylinae), and Prodromus clypeatus (Bryocorinae). These findings provide a progressive phylogenetic framework with new significance for the future phylogenetic improvement and taxonomic revision of Miridae.

Studies of the length–weight relationship (LWR) and condition factor (CF) in fish are abundant but often descriptive; yet, most studies overlook how intrinsic and extrinsic drivers structure these metrics. Here, this study tested whether the growth exponent (b) varies across sex, season, and ecological region, and whether CF is elevated in females and before spawning. Over the course of a complete annual cycle, a total of 1436 individuals were collected from four mudflat sites, measured for total length (TL) and weight (W), and analyzed using log10-linear regressions of LWR and CF, along with appropriate parametric or non-parametric tests under false discovery rate control. The TL strongly predicted W (r² = 0.87) with b = 2.46 ± 0.02 SE, (< 3; p < 0.001), indicating negative allometry. Females showed a larger size and higher b value (2.52) than males (2.41). The dry season yielded a higher b value than the wet season, and southern sites showed a non-significant trend towards a higher b value than northern sites. Mean CF was 1.01 ± 0.01 SE, elevated in females (1.09 vs. 0.98) and in the dry season (1.04 vs. 0.99), while monthly fluctuations (0.89–1.08) tracked feeding and reproduction but showed no regional differences. Overall, S. histophorus exhibits consistently negative allometric growth, with systematic variation in b and CF across sex and season. These findings provide hypothesis-driven baselines for monitoring semi-terrestrial gobies and highlight the importance of considering life-history and hydrological context when applying LWR/CF in ecological and evolutionary research and management.

Hermit crabs use gastropod shells for protection from abiotic stressors and predators. However, two sympatric species of hermit crab, Pagurus hirsutiusculus and Pagurus granosimanus, have divergent shell size preferences. Differences in shell size use were evident in the field: for a given body mass, P. granosimanus used shells that were 136%–300% larger than P. hirsutiusculus. The present study examined the possible morphological adaptations associated with the shell size preferences of P. hirsutiusculus and P. granosimanus as well as the costs and benefits associated with the preference of P. hirsutiusculus for shells that are too small to enclose and protect the entire body of the crab. When exposed to desiccation conditions commonly encountered during low tide emersion, P. hirsutiusculus using large shells survived much longer than individuals using small shells. And in motility trials, P. hirsutiusculus moved significantly faster when using a small shell than when using a large shell. It was therefore hypothesized that P. hirsutiusculus might produce a heavier exoskeleton than P. granosimanus to compensate for the reduced protection obtained by P. hirsutiusculus from small shells. Our findings support this hypothesis: relative to body mass, the carapace was 15%–90% heavier in P. hirsutiusculus than in P. granosimanus, a difference further confirmed by the claw mass, which was 59%–81% heavier in P. hirsutiusculus than in P. granosimanus. The use of larger shells in P. granosimanus provides enhanced protection, allowing for the production of a lighter exoskeleton, but likely imposes reduced motility and increased energetic cost. Pagurus hirsutiusculus, on the other hand, uses smaller, lighter shells that impose lesser energetic costs and allow greater motility but leave the animal more vulnerable to stressors; P. hirsutiusculus compensates for this increased vulnerability by producing a heavier carapace and claws. The differences in shell size and exoskeleton mass suggest ecological implications for these species, particularly with regard to microhabitat use.

The Delacour's langur (Trachypithecus delacouri) is a Critically Endangered primate, restricted to a small region in northern Vietnam. In view of its very small population and existing threats, frequent population monitoring programs are urgently needed for this species. In this study, we evaluated the utility of handheld thermal imaging devices as a complementary tool to conventional ground-based visual surveys for primate population monitoring efforts. Based on results of past studies, we conducted field surveys in Kim Bang Protection Forest, Ninh Binh Province, Vietnam, where the second most important population of the Delacour's langur inhabits. While we followed protocols from previous ground-based visual surveys, we also used thermal monoculars to facilitate langur detections. By integrating thermal handheld devices, we documented at least 18 langur groups with around 116 individuals, an increase of about 11.5% in total population size compared to the most recent extensive study at the same site. When comparing to the 2022 drone survey in Kim Bang, our results also showed that while the drone platform demonstrates superior performance, the integration of thermal imaging devices substantially reduces survey effort relative to conventional ground-based visual techniques. Given the recent regulations on flying drones in remote areas in Vietnam, our findings suggest that thermal imaging devices offer a viable option to improve the efficacy of ground-based primate population monitoring surveys. Furthermore, when properly deployed, handheld thermal devices may provide key advantages for certain primate research topics.

Marine environments are experiencing rapid warming, substantially altering ecosystems. Populations at the edge of a species' range are more vulnerable to environmental change as they are first affected and may have limited dispersal opportunities. This vulnerability may be exacerbated in species with specialised foraging and breeding strategies. The Australian sea lion (Neophoca cinerea) is an endangered otariid species that breeds across a ~3000 km range in southern Australia. At the most north-westerly edge of the species' distribution, Australian sea lions breed across multiple islands within the Houtman Abrolhos Archipelago, Western Australia, a tropical-temperate location affected by marine heatwaves. This study aimed to examine the genetic structure and diversity of the Australian sea lions from the Houtman Abrolhos Archipelago compared to other populations in the species' range. One hundred and twenty-five individuals, 19 from Houtman Abrolhos, were genotyped from 19 sample sites across Western Australia and South Australia. Our findings showed that individuals from the Houtman Abrolhos grouped into a single population, which was highly differentiated and had extremely low genetic diversity. The isolation and limited genetic variation of the Houtman Abrolhos Australian sea lion population suggest that it is extremely vulnerable to extirpation. Our study highlights the vulnerability of isolated populations of a species to rapid environmental change and stochastic events.

Zanovello, L., D. Eisendle, S. Casari, et al. 2026. “Origin and Genetic Diversity of Barbatula (Cypriniformes: Nemacheilidae) in Italy.” Ecology and Evolution 16, no. 1: e72832. https://doi.org/10.1002/ece3.72832.

Appendix 1 of the published article should have included a two-page figure comprising five sub-figures (labeled A to E). However, the published version of this Appendix only contains a single-page figure with three sub-figures (labeled A to C). This has been amended in order to grant the reader complete access to the data presented in the paper.

We apologize for this error.

Gut microbiota generally undergoes dynamic remodeling in concert with multifaceted self-regulation of amphibian hosts during key life stages, such as metamorphosis and hibernation. However, the spatiotemporal dynamics of amphibian gut microbiomes across the lifecycle remain poorly understood. In this study, we applied 16S rRNA gene amplicon sequencing to characterize the gut microbiomes of cultivated Black-spotted frog (Pelophylax nigromaculatus) across seasons. The gut microbiomes exhibited tissue-specific succession, and structural discrepancies between gut regions fluctuated temporally. Both small- and large-intestine microbiomes showed temporal decay patterns in abundance-unweighted intercommunity indices, but not in abundance-weighted indices. Compared with large-intestine microbiomes, small-intestine microbiomes were more randomized yet more centralized in terms of amplicon sequence variants, particularly within Proteobacteria (especially Pseudomonas). The alpha diversity of small-intestine microbiomes was comparatively lower, and their taxonomic composition was more stable over time. We further elucidated the assembly mechanisms of gut microbiomes by systematically analyzing dominant driving factors, ecological processes, phylogenetic traits, source-sink relationships, and co-occurrence networks. Stochastic processes played a dominant role in gut microbiome assembly, while deterministic processes (e.g., habitat filtering and microbial interaction) contributed more strongly to large gut microbiomes than to small gut microbiomes. Overall, this study provides insights into the ecological dynamics and assembly mechanisms of amphibian gut microbiomes across the lifecycle and may inform targeted microbiome modification for amphibian breeding and conservation.

Dormancy has been widely recognized as an evolutionarily conserved strategy that enables cells and organisms to endure environmental stress, resource scarcity, or developmental arrest. While transcriptional regulation has been extensively studied in this context, increasing attention is being directed toward post-transcriptional mechanisms that allow rapid and energy-efficient control of gene expression. Among these, epitranscriptomic modifications, chemical marks added to RNA, have emerged as dynamic and reversible regulators of mRNA fate. In this perspective, it is proposed that RNA modifications can play a central role in establishing and maintaining dormancy across diverse biological systems. Evidence from plant seeds, microbial persisters, stem cells, and dormant cancer cells suggests that specific RNA marks, such as N6-methyladenosine (m⁶A), influence mRNA stability, translation, and localization in a context-dependent manner. It is argued that these modifications serve as a molecular interface between environmental signals and cellular responses, fine-tuning the transition between active and paused states. This article presents a unifying model, grounded in epitranscriptomics, in which RNA modifications modulate entry into, maintenance of, and exit from dormancy across taxa by tuning mRNA stability, translation, and localization—an underexplored regulatory layer in inactive states—and highlights key mechanistic insights, evolutionary parallels, and outstanding questions at the intersection of RNA regulation and cellular dormancy.

In an increasingly fragmented natural world, understanding how different ecological phenomena vary with patch size has many motivations. Examples include the assembly of biodiversity, ecosystem service provision and the suitability of fragments for habitat specialist species. A common approach to such questions divides fragments into small and large size classes for separate analysis. However, lack of an objective definition and means to differentiate ‘small’ from ‘large’ patches limits our ability to compare findings across studies, arguably impeding progress toward any unified views. Because larger and smaller fragments tend, on average, to respectively over-represent narrow- and wide-range species, an ‘area for unbiased species representation’ (A_USR) can be defined at some intermediate fragment size predicted to contain species at incidence frequencies approximating that of the overall landscape. A central tendency for A_USR has previously been estimated for patchy habitats (islands, habitat islands and fragments), providing a benchmark to compare this threshold of small fragment size between studies. However, if A_USR can be readily determined within individual study systems, it would also provide an objective threshold to separate small and large fragments under the A_USR definition. Here we assess this potential for 138 published datasets from various fragmented landscapes using an index comparing species incidence frequencies in each fragment with that of the overall landscape. Regressing this index on fragment area yielded an estimate for A_USR in over 90% of cases, suggesting broad applicability as an objective way to separate fragments into two size classes. Regression slopes provide further information on the relative representation of narrow- vs. wide-range species, with ~80% being numerically consistent with the overall negative trend. Requiring only the same data as the island species-area relationship, A_USR can provide useful insights on the relative importance of narrow- vs. wide-ranging species for studies of patch-size dependence in ecological phenomena.