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1.
Zookeys ; 1185: 143-161, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38074901

RESUMO

The hedgehog genus Mesechinus (Erinaceidae, Eulipotyphla) is currently comprised of four species, M.dauuricus, M.hughi, M.miodon, and M.wangi. Except for M.wangi, which is found in southwestern China, the other three species are mainly distributed in northern China and adjacent Mongolia and Russia. From 2018 to 2023, we collected seven Mesechinus specimens from Anhui and Zhejiang provinces, eastern China. Here, we evaluate the taxonomic and phylogenetic status of these specimens by integrating molecular, morphometric, and karyotypic approaches. Our results indicate that the Anhui and Zhejiang specimens are distinct from the four previously recognized species and are a new species. We formally described it here as Mesechinusorientalissp. nov. It is the only Mesechinus species occurring in eastern China and is geographically distant from all known congeners. Morphologically, the new species is most similar to M.hughi, but it is distinguishable from that species by the combination of its smaller size, shorter spines, and several cranial characteristics. Mesechinusorientalis sp. nov. is a sister to the lineage composed of M.hughi and M.wangi from which it diverged approximately 1.10 Ma.

2.
Animals (Basel) ; 12(15)2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35953902

RESUMO

Understanding the mechanisms influencing patterns and processes of biological diversity is critical to protecting biodiversity, particularly in species-rich ecosystems such as mountains. Even so, there is limited knowledge of biodiversity patterns and processes in the mountains of eastern China, especially about small mammals. In this study, we examined the taxonomic, functional, and phylogenetic diversity of small mammal distribution and community structure along the elevational gradient of Qingliang Mountain, eastern China. We then evaluated how they are influenced by space (area and mid-domain effect (MDE)), environment (temperature, precipitation, and normalized difference vegetation index (NDVI)), and human disturbance. The results showed hump-shaped patterns of taxonomic and phylogenetic diversity along elevation gradients, peaking at 1000 m, unlike functional diversity, which peaked at lower elevations (600 m). The mean pairwise distance and mean nearest taxon distance of functional and phylogenetic variance (MFD and MPD, respectively) were also incongruent. The MFD and MPD showed hump-shaped patterns along elevations; however, unlike MFD, which peaked at lower elevations (600 m), MPD peaked at higher elevations (1200 m). The mean nearest functional taxon distance (MNFD) decreased, while the mean nearest phylogenetic taxon distance (MNTD) increased along the elevation gradient. The higher elevations were functionally more clustered, while the lower elevations were phylogenetically more clustered, suggesting that environmental filtering for traits was stronger at higher elevations. In comparison, phylogenetic conservatism of ecological niches had a stronger influence at lower elevations. The diversity and community structure indices were inconsistently explained, with human disturbance and MDE accounting for the biggest proportions of the model-explained variances. Overall, the results confirm that environmental filtering and human disturbance significantly influence small mammals' diversity and community structure. These findings also emphasize the need for increased conservation efforts in the middle and lower elevation regions of Qingliang Mountain.

3.
Zookeys ; 1083: 129-146, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35115875

RESUMO

Asiatic shrews of the genus Chodsigoa (Soricidae, Eulipotyphla) currently comprise nine species, mostly occurring in southwest China. From May 2017 to August 2020, 11 specimens of Chodsigoa were collected from the Dabie Mountains in Anhui Province, eastern China. Their morphology was compared with other species within the genus and one mitochondrial (cytochrome b) and two nuclear (apolipoprotein B and breast cancer 1) genes were sequenced to estimate the phylogenetic relationships of these specimens. Based on morphological and molecular evidence, these specimens are recognized as a distinct species, Chodsigoadabieshanensis sp. nov., which is formally described here. Morphologically, the new species is most similar to Chodsigoahypsibia, but it is distinguishable from all known congeners by the combination of dark brownish pelage, small size, and relatively short tail. Phylogenetic analyses revealed that C.dabieshanensis sp. nov. forms a phylogenetic lineage sister to the clade containing C.parva + C.hypsibia. The-Kimura 2-parameter genetic distances of the cytochrome b (CYT B) gene between the new species and other nominal Chodsigoa species ranged between 8.6 and 17.6%. The new species is distributed at elevations from 750 to 1250 m in the Dabie Mountains and is geographically distant from other species in the genus.

4.
BMC Ecol Evol ; 21(1): 89, 2021 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-34011264

RESUMO

BACKGROUND: The speckled-pelage brush-furred rats (Lophuromys flavopunctatus group) have been difficult to define given conflicting genetic, morphological, and distributional records that combine to obscure meaningful accounts of its taxonomic diversity and evolution. In this study, we inferred the systematics, phylogeography, and evolutionary history of the L. flavopunctatus group using maximum likelihood and Bayesian phylogenetic inference, divergence times, historical biogeographic reconstruction, and morphometric discriminant tests. We compiled comprehensive datasets of three loci (two mitochondrial [mtDNA] and one nuclear) and two morphometric datasets (linear and geometric) from across the known range of the genus Lophuromys. RESULTS: The mtDNA phylogeny supported the division of the genus Lophuromys into three primary groups with nearly equidistant pairwise differentiation: one group corresponding to the subgenus Kivumys (Kivumys group) and two groups corresponding to the subgenus Lophuromys (L. sikapusi group and L. flavopunctatus group). The L. flavopunctatus group comprised the speckled-pelage brush-furred Lophuromys endemic to Ethiopia (Ethiopian L. flavopunctatus members [ETHFLAVO]) and the non-Ethiopian ones (non-Ethiopian L. flavopunctatus members [NONETHFLAVO]) in deeply nested relationships. There were distinctly geographically structured mtDNA clades among the NONETHFLAVO, which were incongruous with the nuclear tree where several clades were unresolved. The morphometric datasets did not systematically assign samples to meaningful taxonomic units or agree with the mtDNA clades. The divergence dating and ancestral range reconstructions showed the NONETHFLAVO colonized the current ranges over two independent dispersal events out of Ethiopia in the early Pleistocene. CONCLUSION: The phylogenetic associations and divergence times of the L. flavopunctatus group support the hypothesis that paleoclimatic impacts and ecosystem refugia during the Pleistocene impacted the evolutionary radiation of these rodents. The overlap in craniodental variation between distinct mtDNA clades among the NONETHFLAVO suggests unraveling underlying ecomorphological drivers is key to reconciling taxonomically informative morphological characters. The genus Lophuromys requires a taxonomic reassessment based on extensive genomic evidence to elucidate the patterns and impacts of genetic isolation at clade contact zones.


Assuntos
DNA Mitocondrial , Ecossistema , Animais , Teorema de Bayes , DNA Mitocondrial/genética , Etiópia , Filogenia , Ratos
5.
Ecol Evol ; 10(5): 2545-2558, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32185000

RESUMO

Understanding the species diversity patterns along elevational gradients is critical for biodiversity conservation in mountainous regions. We examined the elevational patterns of species richness and turnover, and evaluated the effects of spatial and environmental factors on nonvolant small mammals (hereafter "small mammal") predicted a priori by alternative hypotheses (mid-domain effect [MDE], species-area relationship [SAR], energy, environmental stability, and habitat complexity]) proposed to explain the variation of diversity. We designed a standardized sampling scheme to trap small mammals at ten elevational bands across the entire elevational gradient on Yulong Mountain, southwest China. A total of 1,808 small mammals representing 23 species were trapped. We observed the hump-shaped distribution pattern of the overall species richness along elevational gradient. Insectivores, rodents, large-ranged species, and endemic species richness showed the general hump-shaped pattern but peaked at different elevations, whereas the small-ranged species and endemic species favored the decreasing richness pattern. The MDE and the energy hypothesis were supported, whereas little support was found for the SAR, the environmental stability hypothesis, and the habitat complexity. However, the primary driver(s) for richness patterns differed among the partitioning groups, with NDVI (the normalized difference vegetation index) and MDE being the most important variables for the total richness pattern. Species turnover for all small mammal groups increased with elevation, and it supported a decrease in community similarity with elevational distance. Our results emphasized for increased conservation efforts in the higher elevation regions of the Yulong Mountain.

6.
Zool Res ; 41(6): 670-683, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-32918407

RESUMO

The interpretation of patterns of biodiversity requires the disentanglement of geographical and environmental variables. Disjunct alpine communities are geographically isolated from one another but experience similar environmental impacts. Isolated homogenous habitats may promote speciation but constrain functional trait variation. In this study, we examined the hypothesis that dispersal limitation promotes taxonomic divergence, whereas habitat similarity in alpine mountains leads to functional convergence. We performed standardized field investigation to sample non-volant small mammals from 18 prominent alpine sites in the Three Parallel Rivers area. We estimated indices quantifying taxonomic and functional alpha- and beta-diversity, as well as beta-diversity components. We then assessed the respective importance of geographical and environmental predictors in explaining taxonomic and functional compositions. No evidence was found to show that species were more functionally similar than expected in local assemblages. However, the taxonomic turnover components were higher than functional ones (0.471±0.230 vs. 0.243±0.215), with nestedness components showing the opposite pattern (0.063±0.054 vs. 0.269±0.225). This indicated that differences in taxonomic compositions between sites occurred from replacement of functionally similar species. Geographical barriers were the key factor influencing both taxonomic total dissimilarity and turnover components, whereas functional beta-diversity was primarily explained by climatic factors such as minimum temperature of the coldest month. Our findings provide empirical evidence that taxonomic and functional diversity patterns can be independently driven by different ecological processes. Our results point to the importance of clarifying different components of beta-diversity to understand the underlying mechanisms of community assembly. These results also shed light on the assembly rules and ecological processes of terrestrial mammal communities in extreme environments.


Assuntos
Genoma Mitocondrial , Presbytini/genética , Distribuição Animal , Animais , Ásia , DNA/genética , Fezes/química , Feminino , Masculino , Filogenia , Especificidade da Espécie
7.
Zool Res ; 40(1): 53-60, 2019 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-30581186

RESUMO

The distribution of small mammals in mountainous environments across different elevations can provide important information on the effects of climate change on the dispersal of species. However, few studies conducted on Afromontane ecosystems have compared the altitudinal patterns of small mammal diversity. We investigated the species diversity and abundance of non-volant small mammals (hereafter 'small mammals') on Mt. Kenya, the second tallest mountain in Africa, using a standard sampling scheme. Nine sampling transects were established at intervals of 200 m on the eastern (Chogoria) and western (Sirimon) slopes. A total of 1 905 individuals representing 25 species of small mammals were trapped after 12 240 trap-nights. Abundance was highest at mid-elevations on both slopes. However, species richness and distribution patterns differed between the two slopes. More species were recorded on Chogoria (24) than on Sirimon (17). On Chogoria, species richness was higher at mid-high elevations, with a peak at mid-elevation (2 800 m a.s.l.), whereas species richness showed little variation on the Sirimon slope. These results indicate that patterns of species diversity can differ between slopes on the same mountain. In addition, we extensively reviewed literature on Mt. Kenya's mammals and compiled a comprehensive checklist of 76 mammalian species. However, additional research is required to improve our understanding of small mammal diversity in mountain habitats in Africa.


Assuntos
Distribuição Animal , Biodiversidade , Mamíferos , Altitude , Animais , Quênia , Densidade Demográfica
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