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Background: Chinese giant salamander Andrias davidianus is called "baby fish" in China. Due to its palatability and nutritional value, it was widely cultured in China. The current study was to evaluate the genetic diversity of the farmed A. davidianus. Methods: 30 salamanders were collected from farm and DNA was extracted. Thirty contigs potentially containing SNPs were selected from the previously developed RAD-seq library. The primer was designed and PCR was performed, than the products was sequenced from different direction. At last the sequences were analyzed using the vector NTI 10. Result: 5824bp high-quality sequences embodied in 16 contigs were sequenced and eighty SNP loci were identified which each SNP locus exhibited bi-alleles. The effective allele number from 1.03 to 2.00 and the minor allele frequency was 0.017 to 0.500. The expected heterozygosity was from 0.0333 to 0.5091 and the observed heterozygosity was 0.0333 to 1.0000. Sixty-six of the 80 loci significantly deviated from the Hardy-Weinberg equilibrium (P < 0.05). The results provide useful genomic resources to evaluate the genetic diversity of A. davidianus for conservation and aquaculture. [ABSTRACT FROM AUTHOR]

Poyang Lake is the largest freshwater lake in China and is well known for its ecological function and economic importance. However, due to the influence of clouds, it is difficult to dynamically monitor the changes in water surface areas using optical remote sensing. To address this problem, we propose a novel method to monitor these changes using Sentinel-1A data. First, the Sentinel-1A water index (SWI) was built using a linear model and a stepwise multiple regression analysis method with Sentinel-1A and Landsat-8 imagery acquired on the same day. Second, water surface areas of Poyang Lake from 24 May 2015 to 14 November 2016 were extracted by the threshold method utilizing time-series SWI data with an interval of 12 days. The results showed that the SWI threshold classification method could be applied to different regions during different periods with high quantity accuracy (approximately 99%). The water surface areas ranged between 1726.73 km2 and 3729.19 km2 during the study periods, indicating an extreme variability in the short term. The maximum and average values of the changed areas were 875.57 km2 (with a change rate of 35%) and 197.58 km2 (with a change rate of 8.2%), respectively, after 12 days. The changes in the mid-western region of Poyang Lake were more dramatic. These results provide baseline data for high-frequency monitoring of the ecological environment and wetland management in Poyang Lake. [ABSTRACT FROM AUTHOR]