Project description:Shih-Pin Huang, I-Shiung Chen, Yahui Zhao, and Kwang-Tsao Shao (2018) Microphysogobio luhensis n. sp., a new cyprinid species, is described from the Rongjiang River in eastern Guangdong Province, China. Morphological characters and molecular evidence based on mitochondrial DNA Cytochrome b (Cyt b) and Cytochrome oxidase subunit I (COI) sequences were used to compare this new species with other related species from mainland China, Vietnam and Taiwan. The present molecular evidences revealed that this new species is closely related to M. kachekensis and M. yunnanensis. However, these three species can be well distinguished based on the number of small pearl-like papillae on their inside papillae, lip papillae shape, barbel length, barbel width and color pattern. Furthermore, the morphometric comparison between M. kachekensis and the poorly known species M. yunnanensis is also discussed in this study for the first time. In addition, a diagnostic key to all 14 valid species of Microphysogobio from southern mainland China, Hainan Island and Taiwan is also provided.
Project description:Distribution data on many freshwater fish species in Croatia are scarce and species identifications are difficult, requiring further detailed studies. This paper presents a report of the Italian gudgeon Romanogobio benacensis from the Mirna River in the Istra Peninsula in Croatia, in the south-east from its previously known distribution range. The identification of R. benacensis in Croatia was supported by a morphological comparison with R. benacensis from Italy and Slovenia, the common gudgeon Gobio gobio, and the Danubian gudgeon Gobio obtusirostris from geographically close locations. A combination of character states (number of scales between anus and anal-fin origin, branched pectoral-fin rays, lateral-line scales, total, abdominal, and caudal vertebrae, and the size and number of lateral blotches) distinguishes R. benacensis from both G. gobio and G. obtusirostris. The phylogenetic analyses using mitochondrial sequences of cytochrome b gene confirmed that specimens from the Mirna River belong to R. benacensis. Also, Reka River system (Adriatic Sea basin) in Slovenia is inhabited by a possibly introduced Danubian gudgeon, G. obtusirostris, and not by R. benacensis.
Project description:BackgroundXenophysogobio boulengeri and X. nudicorpa are the only two species within the genus Xenophysogobio (Cyprinidae, Cypriniformes), and both are endemic to the upper reaches of the Yangtze River. In recent years, due to human activities, the natural resources available to both species have declined sharply. Sympatric species with overlapping niches inevitably compete for their habitats, and genetic structure and diversity can reflect population history and their potential for adaptation to changing environments, which is useful for management decisions.MethodsIn the present study, microsatellite DNA and mitochondrial DNA (mtDNA) markers were used to investigate the patterns of population genetic structure for X. boulengeri and X. nudicorpa. Microsatellite DNA data, jointly with traditional summary statistics including F ST and F is, were used to assess the population genetic structure by structure analysis. The mtDNA sequences were then used to examine these patterns through time to detect demographic history.ResultsXenophysogobio boulengeri and X. nudicorpa exhibited high levels of genetic diversity in Yangtze River populations, except for two populations of X. nudicorpa in the Jinsha River, which were low in mtDNA diversity. X. boulengeri showed genetic homogeneity among populations, whereas X. nudicorpa appeared to have significant geographic genetic divergence. Both species experienced a late-Pleistocene sudden population expansion in Yangtze River populations, but not in the Jinsha River populations of X. nudicorpa.DiscussionThe genetic homogeneity of X. boulengeri populations might result from similar population expansion events and environment features. The geographic genetic subdivision for X. nudicorpa between the Jinsha and Yangtze Rivers might be caused by the geographic isolation in the middle Pliocene, as well as climate and environmental heterogeneity.
Project description:BACKGROUND:Organisms need to adapt to keep pace with a changing environment. Examining recent range expansion aids our understanding of how organisms evolve to overcome environmental constraints. However, how organisms adapt to climate changes is a crucial biological question that is still largely unanswered. The plant Arabidopsis thaliana is an excellent system to study this fundamental question. Its origin is in the Iberian Peninsula and North Africa, but it has spread to the Far East, including the most south-eastern edge of its native habitats, the Yangtze River basin, where the climate is very different. RESULTS:We sequenced 118 A. thaliana strains from the region surrounding the Yangtze River basin. We found that the Yangtze River basin population is a unique population and diverged about 61,409 years ago, with gene flows occurring at two different time points, followed by a population dispersion into the Yangtze River basin in the last few thousands of years. Positive selection analyses revealed that biological regulation processes, such as flowering time, immune and defense response processes could be correlated with the adaptation event. In particular, we found that the flowering time gene SVP has contributed to A. thaliana adaptation to the Yangtze River basin based on genetic mapping. CONCLUSIONS:A. thaliana adapted to the Yangtze River basin habitat by promoting the onset of flowering, a finding that sheds light on how a species can adapt to locales with very different climates.
Project description:The freshwater gudgeon Huigobio chenhsienensis (Cypriniformes: Gobionidae) is a small fish endemic to southern China. In this study, we used mitochondrial cytochrome b gene (Cytb), from wide-ranging samplings of H. chenhsienensis from the Ou River (the central of southern China) to the Yangtze River Basin (the northernmost part of southern China) to explore genetic variations and the evolutionary history of H. chenhsienensis in southern China. In total, 66 haplotypes were identified from Cytb sequences of 142 H. chenhsienensis individuals, which could be divided into lineages A, B, and C with divergence times of ~4.24 Ma and ~3.03 Ma. Lineage A was distributed in the lower reaches of the Yangtze River, the Oujiang River, and the Jiao River, lineage B was distributed in the Qiantang River and the Cao'e River, whereas lineage C was restricted to the Poyang Lake drainage from the middle reaches of the Yangtze River. Lineage A could be subdivided into sub-lineages A-I, A-II, A-III, and A-IV, with divergence times of 1.30, 0.97, and 0.44 Ma. Lineage C could be subdivided into sub-lineages C-I and C-II, with a divergence time of 0.85 Ma. Our findings indicate that climate change during the Pliocene and Pleistocene eras, as well as the limited dispersal ability of H. chenhsienensis, have been major drivers for shaping the phylogeographical patterns of H. chenhsienensis.
Project description:Shih-Pin Huang, Yahui Zhao, I-Shiung Chen, and Kwang-Tsao Shao (2017) Microphysogobio zhangi n. sp., a new cyprinid species is described from Guangxi Province, China. Morphological and molecular evidence based on mitochondrial DNA Cytochrome b (Cyt b) sequence were used for comparing this new species and other related species. The phylogenetic tree topology revealed that this new species is closely related to M. elongatus and M. fukiensis. We also observed the existence of a peculiar trans-river gene ow in the Pearl River and the Yangtze River populations, and speculated that it was caused by an ancient arti cial canal, the Lingqu Canal, which forming a pathway directly connecting these two rivers.
Project description: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.
Project description:China has made a concerted effort to successfully improve water quality of rivers, but lake water quality has not improved. Lakes require controls on both catchment external nutrient loads and in-lake internal loads, where nature-based solutions are coupled with engineered systems to achieve the United Nations Sustainable Development Goals (SDGs).
Project description:BackgroundThe Dingqu River Basin, a major tributary of the upper Yangtze River, is located at southeast edge of the Qinghai-Tibet Plateau of China. The fishes of this plateau constitute a major faunal component of this basin, particularly Schizothoracinae (Cypriniformes: Cyprinidae) and Triplophysa (Cypriniformes: Nemacheilidae). Hydropower development is an impact that affects natural habitats and biological resources of the upper Yangtze River and this has led to a decrease in biodiversity. This study investigated the species diversity of fishes of the Dingqu River Basin and accumulated basic data for conservation of biodiversity and assessment of ecological health of the upper Yangtze River.New informationThe upper streams of the Jinshajiang River harbours numerous endemic fish species in China. Most of them belong to the Qianghai-Tibet Plateau fish fauna. However, while the fish species of the Jinshajiang River have been well studied, there is still a gap in the research on fish species diversity of the Dingqu River Basin tributary. This study provides information for 18 native fish species belonging to two orders, four families, three subfamilies and eight genera, and is the first complete record of fishes in the Dingqu River Basin, a primary tributary of the Yangtze River. Supplemental information of species diversity in the Jinshajiang River is also provided. The study includes two datasets, which present taxonomic, distribution, habitat condition, endemism and threat information for each species collected from the Dingqu River Basin and historical literature, respectively. In particular, these fish species all have limited distribution within the south-eastern Qinghai-Tibet Plateau areas of China and could determine the importance of habitat protection for the upper Yangtze River.
Project description:The ecosystem and Pleistocene glaciations play important roles in population demography. The freshwater gudgeon, Gobiobotia filifer, is an endemic benthic fish in the Yangtze River and is a good model for ecological and evolutionary studies. This study aimed to decode the population structure of G. filifer in the Yangtze River and reveal whether divergence occurred before or after population radiation. A total of 292 specimens from eight locations in the upper and middle reaches of the Yangtze River were collected from 2014 to 2016 and analyzed via mitochondrial DNA Cyt b gene sequencing. A moderately high level of genetic diversity was found without structures among the population. However, phylogenetic and network topology showed two distinct haplotype groups, and each group contained a similar proportion of individuals from all sampled sites. This suggested the existence of two genetically divergent source populations in G. filifer. We deduced that a secondary contact of distinct glacial refugia was the main factor creating sympatric populations of G. filifer, and climate improvement promoted population expansion and colonization.