The effects of micro-aeration and substrate selection on domestic sewage treatment performance were explored using three pairs (with or without micro-aeration) of horizontal subsurface flow (HSSF) constructed wetlands (CWs) filled with zeolite, ceramsite or quartz granules. The individual and combined effects of micro-aeration and substrate selection on the purification performance of the experimental-scale HSSF CWs were evaluated. The results showed that micro-aeration significantly increased the treatment efficiencies for chemical oxygen demand, total nitrogen, total phosphorus (TP), ortho-phosphate (PO4(3-)-P) and ammonium nitrogen (NH4+-N) using HSSF CWs, while the substrate selection significantly affected the TP, PO4(3-)-P and NH4+-N removal efficiencies (p<0.05). A two-way analysis of variance (ANOVA) indicated that there was a significant interaction term (i.e. micro-aeration×substrate selection) for NH4+-N removal (p<0.05). Among the three substrates, ceramsite was the best substrate for the treatment of domestic sewage using HSSF CWs. Therefore, the results of this study suggest that a ceramsite-filled HSSF CW with micro-aeration could be the optimal configuration for decentralized domestic sewage treatment.

F1 hybrids may have heterosis in a wide range of traits, such as environmental adaptation or growth condition. To facilitate research on F1 hybrids of Acanthopagrus schlegelii ♂ × Pagrus major ♀, differentially expressed genes of the whole body transcriptome between F1 hybrids and parents were analysed using Illumina high‐throughput sequencing. The results showed that genes related to development and immune process had significantly expressed in F1 hybrids. It revealed that F1 hybrids had quick growth and strong resistance to disease versus A. schlegelii and P. major. This is the first report on the transcriptome of A. schlegelii, P. major and their F1 hybrids at 1 month of age and provides an important foundational data for studying molecular mechanisms of heterosis.

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The complete mitochondrial genome of hybrid F2 from Acanthopagrus schlegelii ($) Â Pagrus major (#) was obtained using high-throughput sequencing technology. The circular genome was 16,648 bp in length, consisting of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a control region. Overall, nucleotide composition was A: 28.02%, T: 27.88%, C: 27.93%, G: 16.17%. Nine genes were encoded on the light strand and the remaining 28 genes were encoded on the heavy strand. All protein initiation codons are ATG except for COI that begins with GTG. The phylogenetic analysis suggested that hybrid F2 of A. schlegelii ($) Â P. major (#) was closest to A. schlegelii. The newly described mitochondrial genome may provide valuable data for the genetic and taxonomic research on artificial hybrid seabream.

Eutrophication often leads to the periodic proliferation of harmful cyanobacterial blooms (HCBs), which threaten the sustainability of freshwater ecosystems and lead to serious environmental, health and economic damage. Hence, it is vitally important to take effective measures to manage HCBs and associated problems. In this study, vertical flow constructed wetlands (CWs) were operated under different hydraulic loading rates (HLRs) to treat a hyper-eutrophic water body with HCBs. Six sampling ports (representing different layers) were evenly distributed along the water flow direction to study the purification processes of CWs. With HLRs ranging from 0.2 m/d to 0.8 m/d, total nitrogen (TN), total phosphorus (TP), COD, total suspended solid (TSS) and Chlorophyll a (Chl.a) were efficiently treated by CWs, and they were mainly removed at the second layer of CWs. The concentrations of two cyanobacterial metabolites (geosmin and β-cyclocitral) in the effluent were mostly below their odorous threshold concentrations. As the HLRs increased, the treatment efficiencies of the CWs decreased gradually. There was no removal of TP, Chl.a, geosmin, or β-cyclocitral at an HLR of 1.0 m/d. Under suitable HLRs, this type of CW could provide a promising way to control HCBs and associated odorous problems in hyper-eutrophic water bodies.