We report here the first application of the Spatially Referenced Regressions on Watershed Attributes (SPARROW) model to China, a country naturally and culturally distinct from previous SPARROW applications. The Songhuajiang River Basin (556,700 km(2)) empties into the Tongjiang monitoring section, a shared water resource of great import for both Chinese and Russian citizens. The model was calibrated to annual loads of total nitrogen (TN) at 102 sites and total phosphorus (TP) at 65 sites. We assessed the rates of delivery and loss of nutrients from diffuse sources and also provided reach-level predictions of the percentage of nutrient loads delivered from upstream subbasins to Tongjiang monitoring section. The results indicated that farmland and pasture land were responsible for about 70 % of nutrient inputs to the Tongjiang monitoring section. Point source inputs were not statistically significant sources of TN or TP. We presented evidence that rice paddies delivered less TN to streams per area than other types of cropland. The locations responsible for the highest TN and TP inputs to the Tongjiang monitoring section tended to be located near the mainstream, though the areas of highest TN delivered yield did not correspond to the areas of highest TP delivered yield. This suggests that different management priorities may be needed in different parts of the Songhuajiang River Basin.
Garra kempi, a small-sized economic fish, is mainly distributed in Tibet of China. In this study, we successfully sequenced the first mitochondrial genome of G. kempi. The mitogenome is 17 104 bp in length, containing 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and 2 control regions (D-loop). Unlike the typical mitochondrial genome organization in vertebrate, the tRNA gene of G. kempi is located between two control regions, and a 246 bp repeat unit is identified in the second control region. In this paper, we utilized 12 protein-coding genes of G. kempi and other 10 closely species to construct the species phylogenetic tree to verify the accuracy of G. kempi.
Elongate loach (Leptobotia elongata (Bleeker)), an endemic fish species to China, is a famous ornamental freshwater fish. Here, a comparative study of mtDNA control region (D-loop) (835 bp) sequences was performed to analyze its wild population structure and evaluate the genetic diversity for 110 individuals from five locations in the upper reaches of the Yangtze River, China. A total of 49 polymorphic sites and 45 haplotypes yielded high haplotype diversity (h=0.952), but low nucleotide diversity (π=0.00454) as that of many fish species.
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