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Prosthogonimus cuneatus and Prosthogonimus pellucidus (Trematoda: Prosthogonimidae) are common flukes of poultry and other birds which can cause severe impacts on animal health and losses to the poultry industry. However, there are limited studies on the molecular epidemiology, population genetics, and systematics of Prosthogonimus species. In the present study, the complete mitochondrial (mt) genomes of P. cuneatus and P. pellucidus were determined to be 14,829 bp and 15,013 bp in length, respectively. Both mt genomes contain 12 protein-coding genes (PCGs) (cox1-3, nad1-6, nad4L, cytb, and atp6), 22 transfer RNA genes, two ribosomal RNA genes, and one non-coding region. Our comparative analysis shows that the atp6 genes of P. cuneatus and P. pellucidus are longer than any previously published atp6 genes of other trematodes. The lengths of the atp6 genes of P. cuneatus and P. pellucidus in this study seem unusual, and should therefore be studied further. The mt genes of P. cuneatus and P. pellucidus are transcribed in the same direction, and the gene arrangements are identical to those of Plagiorchis maculosus, Tamerlania zarudnyi, and Tanaisia sp., but different from those of Eurytrema pancreaticum, Dicrocoelium chinensis, and Brachycladium goliath. The mt genome A + T contents of P. cuneatus and P. pellucidus are 64.47% and 65.34%, respectively. In the 12 PCGs, ATG is the most common initiation codon, whereas TAG is the most common termination codon. The sequence identity of the same 12 PCGs among the eight trematodes (P. cuneatus, P. pellucidus, Pl. maculosus, D. chinensis, E. pancreaticum, B. goliath, T. zarudnyi, Tanaisia sp.) of Xiphidiata are 55.5%-81.7% at the nucleotide level and 43.9%-82.5% at the amino acid level. The nucleotide similarities among the complete mt genomes of the eight trematodes range from 54.1%-81.5%. Phylogenetic analysis based on the aligned concatenated amino acid sequences of the 12 PCGs shows that P. cuneatus and P. pellucidus cluster together and are sister to T. zarudnyi and Tanaisia sp., and this clade is more closely related to E. pancreaticum, Dicrocoelium spp. and Lyperosomum longicauda in the family Dicrocoeliidae, than it is to species in the families Plagiorchiidae and Brachycladiidae. These are the first reported complete mt genomes of Prosthogonimidae, and these data will provide additional molecular resources for further studies of Prosthogonimidae taxonomy, population genetics, and systematics.

The trophic relations of the red-crowned crane species in Zhalong Wetland, northeastern China may change significantly withrapid decrease of biological resources. In this paper, the influence of food resource exhausting on the trophic levels of this vulnerable species was determined by using stable isotope (δ随着扎龙湿地生物资源的迅速减少,在该地栖息的丹顶鹤种群的营养关系可能发生显著的变化.本文使用稳定同位素(δ

The complete mitochondrial genome sequences of Heterakis dispar were determined for the first time in present study. The lengths of mtDNA sequences of H. dispar is 13,995 bp in size, containing 12 ...

The degradation of saline marsh in Songnen plain was controlled by many factors. Based on in-situ observation and laboratory analysis, soil properties and matters translocation in Zhalong wetland at local scale as affected by freeze and thaw action was explored. Results show that within the study plot, 1500 m in distance, but varying only 80 cm in altitude, existed four types of soils i.e. Shallow-horizon Alkalic Halosols (SAH), Crust Alkalic Halosols (CAH) and Para-alkalic Dark-Aquic Cambosols (PDC) and Sodic Hapli-Orthic Gleyosols (SHG). High content total porosity with amounts to 62% in surface horizon in marsh would help to water conservation and wetland formation. In contrast, large rate of silt or clay in texture in alkali soil and meadow soil constrain the water content in topsoil, i.e. the saturated water content 0-30 cm horizon of meadow soil and alkali soil were merely 0.83 and 0.7 m3m-3. Residues & roots in surface layer of SHG expand the period of freezing phase as long as 9 months comparing to 7 months in SAH, and maximum freezing fringe in the former was 24 cm deeper than the latter (178 cm versus 154 cm). Seasonal freeze and thaw action has obvious influence on water storage in topsoil in saline marsh, leading different of soil succession therein. Soil moisture content in the surface layer of marsh increased from 2.05 to 2.62 m3m-3(over-saturated), but no obvious change in PDC and Alkali soils. In contrast, electrical conductivity of saturated paste in SAH and CAH increased from 6.5 to above 10 dS m-1. Therefore, it did not accord with the practical situation of Northeast China as that of strong evaporation was the only cause that caused saline marsh alkalinization. Protecting the vegetation or restoring surface coverage by plant in saline land in spring may help land dealkalization in high latitude arid & semiarid regions.