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1.
J Fish Biol ; 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38712539

RESUMO

The hemicultrine fishes are a group of small-sized cyprinids, widely distributed but endemic to East Asian rivers and lakes. Till now, the taxonomic boundaries and relationships within this group remain poorly explored. In the present study, we study the phylogeny of this group, providing suggestions for classification of the hemicultrine group. Using two mitochondrial and three nuclear genes, and samples representing all genera, our results showed that the group consists of seven major lineages, of which four (Hemiculterella, Hainania, Pseudolaubuca, and Anabarilius) were monophyletic and three (Hemiculter, Toxabramis, and Pseudohemiculter) were not. Based on the phylogenetic tree, we redefined the genera. We revive the genus Siniichthys, which has three species, Siniichthys bleekeri, Siniichthys lucidus, and S. varpachovskii, that were previously treated as members of the genus Hemiculter but showed distant relationships to the genus Hemiculter in our phylogenetic tree. With the new results, a diagnostic key for clades of the hemicultrine group is provided. Furthermore, we provide more detailed information on diagnostic features of the recently described species Hemiculter yungaoi (Vasil'eva et al., 2022). This work will facilitate future systematic studies, pave the way for evolutionary studies, and provide valuable information for the urgent conservation of hemicultrine fishes.

2.
Microbiol Spectr ; 11(6): e0205323, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-37905797

RESUMO

IMPORTANCE: With the development of animal husbandry in China, the production of a large amount of livestock and poultry manure has become one of the main agricultural pollution sources. High-temperature aerobic composting stands out as one of the most crucial methods for the safe and resourceful utilization of livestock and poultry manure, serving as an essential link between crop cultivation, animal breeding, and sustainable agricultural development. Numerous studies have demonstrated that the addition of exogenous multifunctional bacterial agents to compost reduces not only harmful emissions but also sequesters or increases essential nutrients. However, these efficacies depend on the specific functions of the bacteriophage itself, the harmonization and complementarity within the colony, and its ability to adapt to the environment. In recent years, relatively few studies have been conducted on actinomycetes. This experiment provides excellent actinomycete resources for the production of high-efficiency and high-quality compost compound microbial agents of manure and straw.


Assuntos
Actinobacteria , Compostagem , Animais , Actinomyces , Esterco , Criação de Animais Domésticos , Aves Domésticas , Gado , Solo
3.
Parasite ; 30: 22, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37326471

RESUMO

Monogenean parasites are often co-introduced with their fish hosts into novel areas. This study confirmed co-introduction of two dactylogyrids, Dactylogyrus squameus Gusev, 1955 and Bivaginogyrus obscurus (Gusev, 1955), and a newly described gyrodactylid species, Gyrodactylus pseudorasborae n. sp. into Europe along with their fish host, the invasive topmouth gudgeon Pseudorasbora parva (Temminck & Schlegel) from East Asia. All three species were observed in the lower Dnieper and middle Danube basin regions and had slightly larger haptoral hard parts than the same parasites in their native range. While dactylogyrids occurred sporadically, we recorded regular infection by G. pseudorasborae n. sp. at relatively high prevalence and abundance. This latter species was observed in both the native and non-native range of topmouth gudgeon, and resembles Gyrodactylus parvae You et al., 2008 recently described from P. parva in China. Both species were distinguished based on genetic analysis of their ITS rDNA sequence (6.6% difference), and morphometric differences in the marginal hooks and male copulatory organ. Phylogenetic analysis of dactylogyrid monogeneans showed that B. obscurus clustered with Dactylogyrus species parasitising Gobionidae and Xenocyprididae, including D. squameus, supporting recent suggestions of a paraphyletic origin of the Dactylogyrus genus. In addition to co-introduced parasites, topmouth gudgeon was infected with a local generalist, G. prostae Ergens, 1964, increasing the number of monogeneans acquired in Europe to three species. Nevertheless, monogenean infections were generally lower in non-native host populations, potentially giving an advantage to invading topmouth gudgeon.


Title: Les parasites d'un envahisseur à succès : les monogènes du goujon asiatique Pseudorasbora parva, avec description d'une nouvelle espèce de Gyrodactylus. Abstract: Les parasites monogènes sont souvent co-introduits avec leurs hôtes poissons dans de nouvelles zones. Cette étude a confirmé la co-introduction de deux Dactylogyridae, Dactylogyrus squameus Gusev, 1955 et Bivaginogyrus obscurus (Gusev, 1955), et d'une espèce de Gyrodactylidae nouvellement décrite, Gyrodactylus pseudorasborae n. sp. en Europe, en même temps que leur hôte poisson, le goujon envahissant Pseudorasbora parva (Temminck & Schlegel) qui vient d'Asie de l'Est. Les trois espèces ont été observées dans les régions du bas Dniepr et du bassin moyen du Danube et avaient des parties sclérifiées haptorales légèrement plus grandes que les mêmes parasites dans leur aire de répartition d'origine. Alors que les Dactylogyridae étaient rares, nous avons enregistré une infection régulière par G. pseudorasborae n. sp. à une prévalence et une abondance relativement élevées. Cette dernière espèce a été observée à la fois dans l'aire de répartition indigène et non indigène du goujon asiatique et ressemble à Gyrodactylus parvae You et al., 2008 récemment décrit chez P. parva en Chine. Les deux espèces ont été distinguées sur la base de l'analyse génétique de leur séquence ITS de l'ADNr (différence de 6,6 %) et des différences morphométriques dans les crochets marginaux et l'organe copulateur mâle. L'analyse phylogénétique des monogènes Dactylogyridae a montré que B. obscurus se regroupait avec des espèces de Dactylogyrus parasitant les Gobionidae et les Xenocyprididae, y compris D. squameus, soutenant les suggestions récentes d'une origine paraphylétique du genre Dactylogyrus. En plus des parasites co-introduits, le goujon asiatique était infecté par un généraliste local, G. prostae Ergens, 1964, portant le nombre de monogènes acquis en Europe à trois espèces. Néanmoins, les infections par les monogènes étaient généralement plus faibles dans les populations d'hôtes non indigènes, donnant potentiellement un avantage à l'invasion du goujon asiatique.


Assuntos
Cyprinidae , Cipriniformes , Doenças dos Peixes , Parasitos , Trematódeos , Animais , Masculino , Filogenia , Cyprinidae/parasitologia , Trematódeos/genética , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologia
4.
Zool Res ; 43(3): 469-480, 2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35514224

RESUMO

Effective conservation of threatened biota relies on accurate assessments and scientific guidance. As an unfortunate example, Chinese giant salamanders ( Andrias, CGS) remain critically endangered in nature. Misguided conservation efforts, e.g., commercial propagation and releasing of millions of likely non-indigenous or interspecific hybrids, have further compromised conservation initiatives. Limited information on wild populations of CGS poses a significant conservation challenge. Following 18-month long field monitoring, we now report the discovery of a wild population of CGS in a closed nature reserve in Jiangxi Province, China. Genomic assessments reveal its genetic distinctiveness and do not detect genetic admixture with other species. Based on morphological and molecular evidences, we describe this CGS as a new species Andrias jiangxiensis sp. nov. This is the only known species of CGS today with a genetically pure, reproducing, in situ population. This discovery emphasizes the important role that closed nature reserves play in protecting species, and the necessity of integrating long-term field monitoring and genetic assessments. It sets a new pathway for discovering and conserving endangered species, especially for those biotas that are similarly being extirpated by anthropogenic translocations and overexploitation.


Assuntos
Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Animais , China , Urodelos/genética
5.
BMC Ecol Evol ; 21(1): 216, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34852759

RESUMO

BACKGROUND: To determine the presence and abundance of an aquatic species in large waterbodies, especially when populations are at low densities, is highly challenging for conservation biologists. Environmental DNA (eDNA) has the potential to offer a noninvasive and cost-effective method to complement traditional population monitoring, however, eDNA has not been extensively applied to study large migratory species. Chinese sturgeon (Acipenser sinensis), is the largest anadromous migratory fish in the Yangtze River, China, and in recent years its population has dramatically declined and spawning has failed, bringing this species to the brink of extinction. In this study, we aim to test the detectability of eDNA methods to determine the presence and relative abundance of reproductive stock of the species and whether eDNA can be used as a tool to reflect behavioral patterns. Chinese sturgeon eDNA was collected from four sites along the spawning ground across an eight month period, to investigate the temporal and spatial distribution using droplet digital PCR (ddPCR). RESULTS: We designed a pair of specific primers for Chinese sturgeon and demonstrated the high sensitivity of ddPCR to detect and quantify the Chinese sturgeon eDNA concentration with the limit of detection 0.17 copies/µl, with Chinese sturgeon eDNA been intermittently detected at all sampling sites. There was a consistent temporal pattern among four of the sampling sites that could reflect the movement characteristics of the Chinese sturgeon in the spawning ground, but without a spatial pattern. The eDNA concentration declined by approximately 2-3 × between December 2018 and December 2019. CONCLUSIONS: The results prove the efficacy of eDNA for monitoring reproductive stock of the Chinese sturgeon and the e decreased eDNA concentration reflect that Chinese sturgeon may survive with an extremely small number of reproductive stock in the Yangtze River. Accordingly, we suggest future conservation measures should focus on both habitat restoration and matured fish restocking to ensure successful spawning. Overall, this study provides encouraging support for the application of eDNA methods to monitor endangered aquatic species.


Assuntos
DNA Ambiental , Animais , Ecossistema , Espécies em Perigo de Extinção , Peixes/genética , Rios
6.
Ecol Evol ; 11(16): 11323-11332, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34429921

RESUMO

The spatial-temporal patterns of fish assemblages in lotic systems can provide useful information in developing effective conservation measures. This study aimed to explore the spatial and seasonal changes in fish assemblages and their association with environmental factors in mountain streams of the Ren River, southwest China. Field investigations were conducted at 18 sites during the rainy and dry seasons in 2017. A total of 1,330 individuals, belonging to three orders, eight families, 19 genera, and 21 species, were collected. Analysis of similarities (ANOSIM) showed that the structure of fish assemblages varied significantly at the spatial scale, but not at the seasonal scale. In low-order sites, fish assemblages were mainly dominated by cold-water and rheophilic species (e.g., Rhynchocypris oxycephalus, Scaphesthes macrolepis, Metahomaloptera omeiensis, and Gnathopogon herzensteini), while those in high-order sites were predominated by warm-water and eurytopic or stagnophilic species (e.g., Squalidus argentatus, Hemiculter leucisculus, and Zacco platypus). Canonical correspondence analysis (CCA) showed that the fish assemblages were structured by a combination of large-scale landscape factors (e.g., altitude and C-link) and small-scale habitat features (e.g., channel width, water temperature, and depth). Among these factors, landscape had the greatest influence on fish assemblages, while local habitat variables were less important or were only significant in certain seasons.

7.
Mol Ecol Resour ; 21(3): 912-923, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33191666

RESUMO

The edible silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis), which are two of the "Four Domesticated Fish" of China, are cultivated intensively worldwide. Here, we constructed 837- and 845-Mb draft genome assemblies for the silver carp and the bighead carp, respectively, including 24,571 and 24,229 annotated protein-coding genes. Genetic maps, anchoring 71.7% and 83.8% of all scaffolds, were obtained for the silver and bighead carp, respectively. Phylogenetic analysis showed that the bighead carp formed a clade with the silver carp, with an estimated divergence time of 3.6 million years ago; the time of divergence between the silver carp and zebrafish was 50.7 million years ago. An East Asian cyprinid genome-specific chromosome fusion took place ~9.2 million years after this clade diverged from the clade containing the common carp and Sinocyclocheilus. KEGG and GO analyses indicated that the expanded gene families in the silver and bighead carp were associated with diseases, the immune system and environmental adaptations. Genomic regions differentiating the silver and bighead carp populations were detected based on the whole-genome sequences of 42 individuals. Genes associated with the divergent regions were associated with reproductive system development and the development of primary female sexual characteristics. Thus, our results provided a novel systematic genomic analysis of the East Asian cyprinids, as well as the evolution and speciation of the silver carp and bighead carp.


Assuntos
Evolução Biológica , Carpas , Especiação Genética , Animais , Carpas/classificação , Carpas/genética , China , Mapeamento Cromossômico , Feminino , Filogenia , Sequenciamento Completo do Genoma , Peixe-Zebra
8.
Zoolog Sci ; 37(5): 434-443, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32972084

RESUMO

Sinogastromyzon sichangensis is a hillstream loach endemic to the upper Yangtze River, China. It is unclear whether this fish lives in a very restricted area or may be dispersed over a long distance. In the present study spatial connectivity of populations of S. sichangensis was investigated based on 343 individuals collected from 12 sites of Chishui River and employing 22 microsatellite loci. The results of genetic diversity analysis showed that observed heterozygosity (HO) and polymorphism information content (PIC) ranged from 0.5653 to 0.6999 and 0.8513 to 0.8819, respectively. Population structure analysis suggested that S. sichangensis had an unclear genetic structure. AMOVA showed that 69.36% of genetic variation was attributed to differentiation within individuals and all the pairwise genetic differentiation indices (FST) were low (mean FST = 0.0344), indicating weak differentiation among these populations. Estimation of gene flow showed frequent flow among populations, and contemporary levels (mean contemporary migration rate, mc = 0.0131) were approximately equal to historical levels (mean historical migration rate, mh = 0.0147). Individual relatedness analysis revealed a high level of sibship within and among different populations. The frequent gene flow and widespread sibship were due to S. sichangensis laying drifting eggs which travel for a long distance until hatching, after which the juveniles or adults migrate upstream. The results of unclear geographic structure and frequent exchange also indicate that it is necessary to decrease the negative impacts of anthropogenic activities on the connectivity of rivers to protect the migration routes of S. sichangensis.


Assuntos
Distribuição Animal , Cipriniformes/genética , Ecossistema , Rios , Animais , China , Cipriniformes/fisiologia , Fluxo Gênico , Filogenia
9.
Ecol Evol ; 10(12): 5829-5839, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32607193

RESUMO

Habitat alterations that result from anthropogenic disturbance impact both the abiotic and biotic conditions of ecosystems, causing changes in biodiversity in many parts of the world. Recently, the use of functional diversity has been suggested as an approach to better evaluate the effects of such disturbance on particular communities. Here, we investigated the temporal changes in species and functional diversities of fish communities in the downstream area of the Three Gorges Dam (TGD) before, during, and after impoundment. We found two regime shifts in the fish community in 2004 and 2013 following impoundment. Although taxonomic diversity declined sharply at the first regime shift, it increased at the second shift. On the other hand, functional diversity declined throughout the same period, indicating the loss of functional diversity despite increased species diversity. Our analysis also showed that the fish communities shifted from under-dispersion to over-dispersion due to both a decrease in the relative abundance of migratory fish and an increase in the number of fish adapted to the new hydrologic conditions. Our results indicated that the impacts of dams on downstream fish communities may change over time. Interactions between species may become more important when the environment is stable.

10.
Zool Res ; 41(4): 423-430, 2020 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-32521574

RESUMO

The Chinese sturgeon ( Acipenser sinensis Gray, 1835) is a large anadromous fish species, which is under considerable threat due to dramatic declines in population numbers. In the current study, population genetic diversity and individual reproductive success were assessed using nuclear microsatellite markers (simple sequence repeat, SSR) and complete mitochondrial (mtDNA) genome analysis of juveniles born in 2014. Results showed the existence of size polymorphism in the mtDNA genome of Chinese sturgeon, which was caused by a repeat motif. Population genetic diversity was high based on both SSR ( Ho: 0.728±0.211; He: 0.779±0.122) and mtDNA genome analyses ( H: 0.876±0.0035; Pi: 0.0011±0.0010). A positive inbreeding coefficient ( FIS: 0.066±0.143) was also found, indicating the occurrence of inbreeding. Reconstruction of sibling groups identified 11 mothers and 11 fathers involved in reproduction of Chinese sturgeons in 2014. Variance in individual reproductive success was not significant, with reproductive success of parent fish instead shown to be relatively even ( P=0.997>0.05), thus suggesting the absence of sweepstakes reproductive success (SRS). These results indicate that, in regard to conservation, loss of genetic diversity due to the effects of SRS is not of particular concern. However, we must focus on having an adequate number of adults and suitable environmental conditions to ensure that fish can reproduce.


Assuntos
Peixes/fisiologia , Variação Genética , Reprodução , Animais , China , Conservação dos Recursos Naturais , Feminino , Peixes/genética , Masculino , Repetições de Microssatélites , Rios
11.
Phys Rev Lett ; 124(8): 083605, 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-32167349

RESUMO

We demonstrate the experimental generation of orbital angular momentum (OAM) multiplexed multipartite entanglement with cascaded four-wave mixing processes in a continuous variable (CV) system. In particular, we implement the simultaneous generation of 9 sets of OAM multiplexed tripartite entanglement over 27 Laguerre-Gauss (LG) modes, as well as 20 sets of OAM multiplexed bipartite entanglement over 40 LG modes, which show the rich entanglement structure of the system. In addition, we also generate tripartite entanglement of three types of coherent OAM superposition modes. Such OAM multiplexed multipartite entanglement opens the avenue to construct CV parallel quantum network for realizing parallel quantum information protocols.

12.
Ecol Evol ; 9(12): 7227-7236, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31380045

RESUMO

Knowledge of food resource partitioning among sympatric fish species is crucial for understanding the potential mechanisms of species coexistence. Gudgeons (Teleostei: Cyprinidae: Gobioninae) often dominate fish assemblages in the upper Yangtze River. However, little research has been conducted on their trophic interactions. In this paper, seasonal diet and feeding strategy variations of four sympatric gudgeon species, Coreius guichenoti, Coreius heterodon, Rhinogobio ventralis, and Rhinogobio cylindricus, were investigated by analysis of intestinal tract contents, aiming to explore whether food resource partitioning occurred among them. Fish specimens were collected during spring (April-May) and autumn (August-October) in 2010 in Hejiang, a free-flowing stretch of the upper Yangtze River. Coreius guichenoti, C. heterodon, and R. cylindricus showed omnivorous feeding habits, while R. ventralis exhibited an obligate carnivore feeding habit. Diet overlap among the four studied species was high, especially in spring. However, changes in feeding strategies were observed in autumn. Specifically, C. guichenoti and R. cylindricus expanded their dietary niche breadth and consumed detritus, Sinopotamidae or Hydropsychidae as important complementary food resources. In contrast, C. heterodon and R. ventralis reduced their dietary niche breadth and became more specialized on mussels (Limnoperna lacustris). These results confirmed that sympatric fish species can coexist with high diet overlap, and food resource partitioning among these species may also fluctuate with the seasons.

13.
Zool Res ; 40(5): 427-438, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31111694

RESUMO

Small populations with low genetic diversity are prone to extinction. Knowledge on the genetic diversity and structure of small populations and their genetic response to anthropogenic effects are of critical importance for conservation management. In this study, samples of Ancherythroculter nigrocauda, an endemic cyprinid fish from the upper reaches of Yangtze River, were collected from five sites to analyze their genetic diversity and population structure using mitochondrial cytochrome b gene and 14 microsatellite loci. Haplotype diversity, nucleotide diversity, and expected heterozygosity indicated that the A. nigrocauda populations had low genetic diversity, and decreased heavily from 2001 to 2016. Significant genetic differentiation was found among different populations in the cyt b gene and SSR markers based on the genetic differentiation index (F ST), whereas no differentiation was found in 2001. Haplotype genealogy showed that eight out of 15 haplotypes were private to one population. The SSR STRUCTURE analysis showed that there were four genetic clusters in the A. nigrocauda samples, with each population forming a single cluster, except for the Chishui River (CSR) and Mudong River (MDR) populations, which formed a common cluster. Therefore, loss of genetic diversity and increased genetic differentiation were found in the A. nigrocauda populations, which could be attributed to dam construction, overfishing, and water pollution in the upper Yangtze River. It is therefore recommended that the government should ban fishing, control water pollution, increase river connectivity, and establish artificial breeding and stocking.


Assuntos
Distribuição Animal , Cyprinidae/genética , Variação Genética , Rios , Animais , China , Citocromos b/genética , Marcadores Genéticos , Haplótipos , Filogenia , Fatores de Tempo
14.
Ecol Evol ; 9(5): 2664-2677, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30891207

RESUMO

Opsariichthine (sensu Oceanologi Et Limnologia Sinica, 1982, 13, 293-298) is a cyprinid group consisting of five genera and endemic to East Asia. Previous studies suggested that there may be many possible cryptic species in this group, but this has not been confirmed. In this study, using mitochondrial cyt b sequences on 1,388 samples and 739 haplotypes, we showed very high species diversity within this group. The results showed that phylogenetic relationships of the opsariichthine group were as ([Nipponocypris-Parazacco-Candidia] + [Zacco + Opsariichthys]), and there were multiple deep lineages within several species, flagging putative cryptic species. When a 3% genetic distance was used as a threshold for species delimitation, 35 haplogroups were found, nine haplogroups in Candidia-Parazacco-Nipponocypris group, six haplogroups in the Zacco group, and 20 haplogroups in the Opsariichthys group. We consider all of them to be putative until determination of distinct species based on the tree topology, geographic distributions, or a combination of both. In addition, two kinds of species delimitation tools, ABGD and PTP, were applied to construct molecular operational taxonomic units (MOTUs). The ABGD method revealed nine MOTUs in Candidia-Parazacco-Nipponocypris group, two MOTUs in the Zacco group, and 17 MOTUs in the Opsariichthys group. And the PTP method revealed 10 MOTUs in Candidia-Parazacco-Nipponocypris group, 10 MOTUs in the Zacco group, and 29 MOTUs in the Opsariichthys group. Therefore, there should be more species in the opsariichthine group than presently described. Based on the molecular data and morphological characteristics, we proposed Opsariichthys macrolepis as a valid species and described its morphological diagnostic characters.

15.
Sci Rep ; 9(1): 3612, 2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30837645

RESUMO

The minimum viable population (MVP) size has been compared for a wide range of organisms in conservation biology, but a limited number of studies investigated it for freshwater fishes, which exhibit diverse life history strategies. In this study, the MVP size and population growth rate of 36 fish species in the Yangtze River were estimated and compared with their life-history traits. The results indicated that the MVP size ranged from 42 to 320 individuals, and instantaneous per-capita population growth rate ranged from 0.009 to 0.188 per year. MVP size and population growth rate were significantly associated with three life history traits: the age at maturity, generation time, and fecundity. Long-lived species with delayed maturation, long generation time, and high fecundity had a greater MVP size and a lower population growth rate than short-lived species. Therefore, our results emphasize a need for prioritizing our conservation effort more on long-lived species.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Peixes/crescimento & desenvolvimento , Características de História de Vida , Densidade Demográfica , Crescimento Demográfico , Animais , Peixes/fisiologia , Especificidade da Espécie
16.
Sci Rep ; 9(1): 4212, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30862788

RESUMO

Dams have well-documented ecological impacts on downstream river segments; however, long-term impacts of river impoundment have rarely been investigated in upstream reaches. Using data from long-term standardized surveys, we analyzed temporal changes in fish assemblages in the Yangtze River upstream of the Three Gorges Dam (TGD) before, during and after its construction. Our analysis indicated fish assemblage regime shifts in the two closer reaches in 2008, in accordance with the filling to 172.5 m in 2008; and in the other reach, farthest from the TGD, in 2011, indicating timing of the effects being related to distance. These shifts were evident in relative abundance of native fish species rather than non-native species and have altered community structures and functional groups. Relative abundance of the lotic guilds declined in the two closer reaches, but increased in the farthest. Invertivores declined, but piscivores and opportunistic life-history strategists increased in all reaches. We conclude that construction of TGD had led to significant changes in species distributions influenced by species functional traits. Our findings emphasize the need for long-term monitoring of fish assemblages before and after dam construction in order to understand ecological responses to hydrological changes for effective resource management in regulated rivers.


Assuntos
Ecossistema , Peixes/fisiologia , Modelos Biológicos , Animais , China , Monitoramento Ambiental , Rios
17.
Sci Rep ; 8(1): 11703, 2018 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-30076386

RESUMO

Understanding how populations adapt to different thermal environments is an important issue for biodiversity conservation in the context of recent global warming. To test the hypothesis that populations from southern region are more sensitive to climate change than northern region in cold-water species, we determined the thermal tolerance of two geographical populations of a cold-water fish, Rhynchocypris oxycephalus: the Hangzhou population from southern region and the Gaizhou population from northern region, then compared their transcriptomic responses between a control and a high temperature treatment. The results showed that the thermal tolerance range and thermal tolerance polygon area of Hangzhou population were narrower than the Gaizhou population, indicating populations from southern region were possibly more vulnerable. Further transcriptomic analysis revealed that the Gaizhou population expressed more temperature responding genes than the Hangzhou population (583 VS. 484), corresponding with their higher thermal tolerance, while some of these genes (e.g. heat shock protein) showed higher expression in the Hangzhou population under control condition, suggesting individuals from southern region possibly have already responded to the present higher environmental temperature pressure. Therefore, these results confirm the prediction that populations from southern region are more sensitive to global warming, and will be important for their future conservation.


Assuntos
Adaptação Fisiológica/genética , Cyprinidae/genética , Cyprinidae/fisiologia , Temperatura , Transcriptoma/genética , Aclimatação/genética , Animais , China , Regulação da Expressão Gênica , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Resposta ao Choque Térmico/genética , Anotação de Sequência Molecular , Estresse Fisiológico/genética , Água
18.
Vet Microbiol ; 214: 36-43, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29408030

RESUMO

Candida albicans is the most prevalent opportunistic fungus of humans and animals. While most studies focus on human isolates, they rarely focus on poultry isolates. In this study, C. albicans strains were recovered from poultry in the southern Hebei Province (China) and identified. Molecular typing and analyses were performed to understand the molecular epidemiology and genetic relatedness of the strains. The fungi were isolated from live birds with presumed candidiasis or their corpses. The isolates were identified based on morphology, differential medium culture, and rDNA internal transcribed spacer sequencing. The identified C. albicans strains were analyzed by ABC genotyping and multilocus sequence typing. Clonal groups were identified using the eBURST (version 3.0) software, and an UPGMA phylogenetic tree was constructed using the MEGA (version 6.06) software. Overall, 72 isolates were divided into three genotypes (A, B, and C), 48 novel sequence types (STs), five groups with 10 singletons, and four clades. Results indicated that candidiasis is common in poultry in the southern Hebei Province, and that the genetic composition of the C. albicans poultry population from the area is relatively complicated. Based on the eBURST analysis for the STs in this study and others, we suggest that C. albicans poultry isolates were relatively independent but not completely separated from human isolates. The strains with the same or closely related genotypes but recovered from both birds and humans could have transferred and evolved between the two types of host.


Assuntos
Candida albicans/genética , Candida albicans/isolamento & purificação , Candidíase/microbiologia , Galinhas/microbiologia , Aves Domésticas/microbiologia , Animais , Candida albicans/classificação , Candidíase/epidemiologia , Candidíase/transmissão , China/epidemiologia , Genótipo , Humanos , Tipagem Molecular/métodos , Tipagem de Sequências Multilocus/métodos , Filogenia
19.
Zootaxa ; 4532(3): 367-384, 2018 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-30647354

RESUMO

Two new species of the fish genus Garra (Cypriniformes: Cyprinidae) are described from the lower Yarlung Tsangpo River drainage in southeastern Tibet, China. Garra motuoensis, a member of the proboscis species group, is primarily distinguished from the members of this group by having a prominent, quadrate, and slightly bilobed proboscis; 6-20 small to middle-sized unicuspid tubercles on the anterior region of the proboscis, some middle-sized unicuspid tubercles on the transverse lobe of the snout, and several small unicuspid tubercles on the lateral surface of snout; the anus situated slightly closer to the anal-fin origin than to the pelvic-fin origin (distance from anus to anal fin 36-46% of pelvic-anal distance); 36-37 lateral-line scales; and 12 circumpeduncular scales. Garra yajiangensis, a member of the proboscis species group, is primarily distinguished from the members of this group by having a prominent, quadrate, and slightly bilobed proboscis, covered with 2-7 middle-sized unicuspid tubercles, including two large-sized tubercles on anterior margin of each lobe; some small unicuspid tubercles on the transverse lobe and the lateral surface of snout; the anus situated substantially closer to the anal-fin origin than to the pelvic-fin origin (distance from anus to anal fin 19-24% of pelvic-anal distance); 34-36 lateral-line scales; and 12 circumpeduncular scales. The validities of these two new species were also corroborated by molecular phylogenetic analysis based on Cyt b gene sequences.


Assuntos
Cipriniformes , Animais , China , Cyprinidae , Filogenia , Rios , Tibet
20.
Zootaxa ; 4527(3): 392-402, 2018 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-30651433

RESUMO

Exostoma tibetana, new species, is described from the lower Yarlung Tsangpo River drainage in southeastern Tibet, China. It is distinguished from congeners by having an adipose fin separate from the upper procurrent caudal-fin rays and incised at the posterior extremity of its base; the tip of the pelvic fin not reaching to the anus when adpressed; 10 branched pectoral-fin rays; and morphometric features associated with the body depth, adipose-fin base length, caudal-peduncle depth, snout length, and eye diameter. The validity of this new species was also supported by molecular phylogenetic analysis based on Cyt b gene sequences.


Assuntos
Peixes-Gato , Distribuição Animal , Animais , China , Filogenia , Rios , Tibet
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