Meihua Xiong

Feeding habits and habitats preferences affecting mercury bioaccumulation in 37 subtropical fish species from Wujiang River, China.

The present study is the first to report the total mercury concentration of 37 fish species collected from Wujiang River, which is the largest branch on the southern bank of Yangtze River, China and proposed for hydropower development. Total mercury concentrations varied among the 37 subtropical species examined. We found higher mercury concentrations in carnivorous species demonstrating greater mercury bioaccumulation in species with more predatory feeding habits. There is no significant difference between fish grouped by habitat preference and feeding habit. However, carnivorous species preferring benthic positions had higher total mercury concentrations than others suggesting that mercury accumulation is related to the interaction of feeding habit and habitat preference. In our study, fish that are bottom living and feed on other fish or aquatic animals are more likely at high risk of mercury exposure. Additional mercury contamination and future impoundment may raise mercury concentration in fish in the Wujiang causing concern for human health and ecological impacts.

Characterization of microsatellite loci in Sinilabeo rendahli and cross-amplification in four other Chinese cyprinid species

Twenty-eight microsatellite loci were isolated in Sinilabeo rendahli, an endemic cyprinid fish in China. In a test on a population of 48 individuals, 15 primer pairs exhibited polymorphism with 2–12 alleles per locus, while the rest 13 were monomorphic. Observed and expected heterozygosities ranged from 0.104 to 0.915 and 0.195 to 0.865, respectively. Four loci showed significant deviation from Hardy–Weinberg equilibrium and two of them had evidence of null alleles. Twenty-six markers successfully cross-amplified in at least one of the four additional Chinese cyprinid species (Garra pingi pingi, Pseudogyrincheilus procheilus, Discogobio yunnanensis and Onychostoma sima) examined in this study.

Isolation and characterization of 15 microsatellite loci in an endemic Chinese cyprinid fish, Pseudogyrincheilus prochilus , and their cross-species amplification in two related species

Fifteen polymorphic microsatellite loci were developed for an endemic Chinese cyprinid fish, Pseudogyrincheilus prochilus. The number of observed alleles per locus ranged from 2 to 17. The observed and expected heterozygosities ranged from 0.067 to 1.000 and from 0.066 to 0.932, respectively. No significant linkage disequilibrium was detected among the loci. Two loci showed significant deviation from Hardy–Weinberg equilibrium, and one of them had evidence for null alleles. Fourteen primer pairs cross-amplified in Garra pingi pingi, and 13 primer pairs cross-amplified in Onychostoma sima. These microsatellite loci should prove highly informative for future studies of genetic diversity conservation.

Complete mitochondrial genome of Pareuchiloglanis sinensis (Siluriformes: Sisoridae).

Abstract The complete mitochondrial genome of Pareuchiloglanis sinensis, an endemic Chinese sisorid fish, was determined by DNA sequencing based on the PCR fragments. The complete mtDNA genome sequence of P. sinensis is 16,593 bp in length, with a gene content of 13 protein-coding, 2 ribosomal RNA, and 22 transfer RNA genes, and a typical gene arrangement identical to many other reported fishes. The overall base composition of the heavy strand was 30.6% A, 24.2% T, 16.0% G and 29.2% C, with a relatively high A + T content (54.8%). This will provide a useful tool for understanding the genetic diversity, population structure and conservation status of P. sinensis in future.

The complete mitochondrial genome of Jinshaia sinensis (Teleostei, Balitoridae, Balitorinae)

Abstract Jinshaia sinensis is an endemic and typical fish which is successfully adaptive to mountain torrents in the upper stream of the Yangtze River and its tributaries. In this study, the complete mitogenome sequence of J. sinensis has been first sequenced by DNA sequencing based on the PCR fragments. The mitogenome, consisting of 16,567 base pairs (bp), had typical vertebrate mitochondrial gene arrangement, including 13 protein coding genes, 22 transfer RNAs, 2 ribosomal RNA genes and a noncoding control region (CR). The overall base composition of J. sinensis is 30.37% A, 28.82% C, 16.59% G, and 24.22% T, with a relatively a slight AT bias of 54.59%. CR of 903 bp length is located between tRNAPro and tRNAPhe. The complete mitochondrial genome may provide fundamental informative data not only for unravel the population structure and differentiation, but also for further conservation genetics studies on this balitorid species.

Ten polymorphic microsatellite loci developed from Triplophysa anterodorsalis

Triplophysa anterodorsalis is a genus Triplophysa (Rendahl) fish which belongs to the family Balitoridae, subfamily Nemacheilinae. There are 112 nominal species in the genus Triplophysa all over the world, and ∼60% of species are found in China (Chen and Yang 2005; Froese R. and Pauly D. 2008 FishBase: www.fishbase.org, ver. (06/2008)). T. anterodorsalis is an endemic fish, distributed in upper reaches of the Yangtze river, Jinsha river and its tributaries (Ding 1994). But, since 2002, four cascade hydropower stations were under construction in the lower reaches of Jinsha river (Chen et al. 2005). Fragmentation caused by these dams might disrupt the connectivity of hydro-ecosystem and the gene flow between local fish populations (Fu et al. 2003; Jiang et al. 2007; Huang et al. 2011). Due to human activities, such as overfishing, dam construction, water contamination and habitat alteration, wild fisheries of this species have declined dramatically, and the distribution ranges have been shrinking rapidly in the last decades (Gao et al. 2011). In the long run, a good understanding of the genetic diversity, population structure and differentiation of T. anterodorsalis is required in order to establish adequate management plans for the conservation of this species. While the need for restoration of T. anterodorsalis, has been recognized, a eight-year management project based on population genetics has been initiated to define the efficiency of these conservation measures since 2011 (Yu and Chen 2011). In the present study, we isolated and characterized 10 microsatellites from T. anterodorsalis. These markers will be a useful tool for studies of population demographic history, genetic structure and conservation purposes in this species.

Development of sixteen novel polymorphic microsatellite markers in Rhinogobio ventralis (Teleostei, Cyprinidae, Gobioninae)

Abstract In the present study, we developed 16 polymorphic microsatellite loci in Rhinogobio ventralis, an endemic cyprinid fish in the upper reaches of the Yangtze River. The polymorphism of each locus was assessed in 32 individuals collected from Jiangjin section of the Yangtze River. A total of 126 alleles were detected and the number of alleles per locus ranged from 2 to 16. The observed and expected heterozygosities ranged from 0.161 to 0.968 and from 0.154 to 0.928, respectively. Two loci significantly deviated from Hardy–Weinberg equilibrium. No significant linkage disequilibrium was found between pairs of loci. These polymorphic microsatellites will be useful tools in the study of genetic diversity and population structure of R. ventralis.

Development of seventeen polymorphic microsatellite loci in Spinibarbus sinensis (Bleeker)

We developed 17 polymorphic microsatellite loci in Spinibarbus sinensis. All markers were obtained from partial genomic DNA libraries enriched for tetranucleotide repeats and characterized in 32 unrelated individuals from one putative population in Wujiang River. The number of alleles ranged from 3 to 17, with an average of 7.471 per locus. The expected and observed heterozygosity values ranged from 0.647 to 0.910 and 0.333 to 1.000, respectively. Three loci showed significant deviation from Hardy–Weinberg Equilibrium. No significant lingkage disequilibrium was found. These polymorphic loci described for S. sinensis will be valuable as genetic markers for use in breeding, genetic management and conservation studies.

Isolation and characterization of microsatellite loci in Jinshaia sinensis

In this study, we isolated and characterized thirteen polymorphic microsatellite markers for Jinshaia sinensis, a fish species endemic to the upper reaches of the Yangtze River in China. Each locus was screened in a population of 48 individuals. Number of alleles per locus ranged between five and nineteen. Observed heterozygosity ranged between 0.121 and 0.854, and expected heterozygosity between 0.722 and 0.928. No significant linkage disequilibrium was found between pairs of loci. However, three loci showed significant departures from Hardy-Weinberg equilibrium and four loci had evidence of null alleles. These markers presented here will be valuable tools to understand the genetic structure of J. sinensis populations in the Yangtze River.

Microsatellites development for rock carp ( Procypris rabaudi ) and cross-species testing in Onychostoma sima and Spinibarbus sinensis

A total of thirty-six microsatellite loci were isolated and characterized in the endemic and endangered fish species rock carp (Procypris rabaudi) from China. Each locus was screened in a population of natural and artificial breeding individuals. The number of alleles observed per locus ranged from 2 to 13. The observed and expected heterozygosities ranged from 0.267 to 1.000 and 0.378 to 0.910. No significant linkage disequilibrium was detected among the loci. Significant deviations from Hardy–Weinberg equilibrium were found in fifteen loci, of which seven loci had evidence of null alleles. Twenty-five primer pairs cross-amplified in Onychostoma sima while thirty-two primer pairs cross-amplified in Spinibarbus sinensis. These microsatellite loci will be useful for future investigation on genetic population structure of P. rabaudi as well as other related species.