Abstract:The tbx20 mutated zebrafish line is successfully established by using CRISPR/Cas9 system. The tbx20 mutagenesis efficiency is about 42.1% which was evaluated by T7E1 assay in F₀. Sequencing analysis estimated the germline transmission efficiency of tbx20 mutagenesis is 36.7% in F₁. The tbx20 homozygote mutant showed obvious cardiac phenotypes:the tbx20 mutant displayed pericardial oedema, sinus congestion, looping abnormal and the cardiac morphology deformation at 48 hpf; all the phenotypes became severer at 3 dpf and tbx20 mutant showed linear heart. In situ hybridization and realtime fluorescence quantitative PCR results revealed that the expression of vmhc was upregulated, amhc and myl7 in the tbx20 mutants were downregulated. The tbx20 mutated zebrafish line was successfully produced and was confirmed tbx20 affected heart looping, which established a foundation for future studies on the function of tbx20 gene in early cardiac chamber differentiation.

Abstract:To identify the species of the tapertail anchovies rapidly, Coilia brachygnathus, C. nasus and C. nasus taihuensis distributed in freshwater lakes of the Yangtze River Basin, single nucleotide polymorphism (SNP) molecular markers were developed to distinguish them. Twenty SNP markers were randomly selected with fixation index (F_st) of 1 from the 120 loci found between C. brachygnathus and C. nasus; and 10 SNP markers were ramdomly selected with high F_st value from the 21 loci found between C. nasus and C. nasus taihuensis for primers designing. Twenty C. brachygnathus, 20 C. nasus taihuensis and 12 C. nasus were randomly amplified and sequenced using the primers designed. The results showed that each of the 19 SNP markers can be used to completely distinguish C. brachygnathus and C. nasus, and no polymorphic sites were found in the other locus in the samples tested. Eight SNP makers were successfully amplified and used to distinguish C. nasus and C. nasus taihuensis. Marker Ct-Cn_wta showed the highest difference in genotype frequency between C. nasus and C. nasus taihuensis. When marker Ct-Cn_wtap and Ct-Cn_eif2b4 SNP were used, the successful identification rate on C. nasus and C. nasus taihuensis reached 100%. In conclusion, a robust and efficient method is provided to identify the tapertail anchovies, C. brachygnathus, C. nasus and C. nasus taihuensis using SNP molecular marker, which would provide an important tool for identification and conservation of the tapertail anchovies.

Abstract:C-type lectins are a superfamily of Ca²⁺-dependent carbohydrate-binding proteins that play crucial roles in invertebrate immunity. A novel C-type lectin gene (ScCTL-2) was identified in razor clam Sinonovacula constricta. Sequence analysis showed that the full length ScCTL-2 contains a 1893 bp ORF encoding 630 amino acid polypeptide with four CTLD (C-type lectin domain) and a N-terminal transmembrane region. The special structure of ScCTL-2 protein revealed that ScCTL-2 is perhaps a new group of invertebrate C-type lectins. The ScCTL-2 was expressed in almost all tissues, with highest expression in hepatopancreas and the second highest expression in gill. Bacterial stimulation up-regulated ScCTL-2 expression in hemocytes. The spatial-and temporal-specific expression patterns of ScCTL-2 suggest it may be an immune-related gene in razor clam. Recombinant protein (rScCTL-2) displayed a broad bacterial agglutination spectrum, and the agglutinate activity was strictly Ca²⁺-dependent. It could agglutinate all the experimental bacteria only if Ca²⁺ existed. The results suggest ScCTL-2 is a novel gene possessing common immune characteristics of invertebrate C-type lectins.

Abstract:To evaluate the anti-inflammation effect of pterostilbene on RAW264.7 macrophages, an inflammation model in vitro was established by lipopolysaccharide (LPS) stimulation. After exposing RAW264.7 cells to pterostilbene and LPS, the mRNA expression of inflammatory cytokines including monocyte chemoattractant protein (MCP)-1, interleukin (IL)-6 and IL-1β, tumor necrosis factor (TNF)-α, and inducible nitric oxide synthase (iNOS) were detected by real-time quantitative polymerase chain reaction (qPCR). Nitric oxide (NO) production in supernatant was analyzed using Griess method. The protein expression of extracellular regulated protein kinases (ERK),c-Jun N-terminal kinase (JNK),p38 mitogen-activated protein kinase (p38 MAPK) and Nuclear factor-κB p65 (NF-κB p65) were detected by Western blot analysis. The results showed that pterostilbene significantly inhibited the gene expression of inflammatory cytokines and the production of NO. Pterostilbene significantly suppressed LPS-induced ERK, p38 and p65 phosphorylation. Data showed that pterostilbene could inhibit the mRNA expression of LPS-induced inflammatory cytokines including MCP-1, IL-6, IL-1β, TNF-α and iNOS, and the release of NO, and its mechanism may be related to blocking the mitogen-activated protein kinase (MAPK) and NF-κB pathway.

Abstract:In 2015, the phytoplankton sampling was conducted in Qiandao Lake, and the phytoplankton community structure characteristics, the trend of change and the division of phytoplankton functional groups were studied. Two hundred and one species of phytoplankton were identified. The number of species of Cyanobacteria, Cyanobacteria and diatoms was dominant throughout the year. The average biological density in 2015 was (1285.41 ±448.43)×10⁴ cells/L, and the average biomass was (2.75 ±0.81) mg/L. There were significant differences in biological density and biomass between months (P<0.001). Phytoplankton functional groups S1 and H1 had higher abundance ratio in the four seasons. The B phytoplankton functional groups had a higher proportion in spring and winter, and the J phytoplankton functional groups accounted for higher ratios in spring, summer and autumn. K was higher in spring and autumn, and TC was higher in summer, autumn and winter. M, LO and P phytoplankton functional groups have higher abundance ratio in autumn and summer' and the Y functional group and D functional group are higher in winter only. CCA canonical correspondence analysis revealed the relationship between functional groups and water temperature and nutrients.

Abstract:The Qingcaosha reservoir in the Yangtze River estuary is a special system for water supply and the water quality is mainly controlled through biological manipulation methods by Hypophthalmichthys molitrix(H.molitrix) and Hypophthalmichthys nobilis(H.nobilis). A total of 139 tails of H.molitrix and 59 H.nobilis were collected from June 2015 to May 2017. Their ages were identified through the scales or vertebrae, and their growth characteristics were studied based on ages. The results showed that:the age of H.molitrix ranged from 1 to 10 years old and most of them ranged from 3 to 4 years old; The age of H.nobilis was composed of 1 to 11 years old, most of them were 2 or 3 years old. The formula of body length and weight of H.molitrix and H.nobilis were W=0.037 9L^3.027 and W=0.039 0L^2.946 respectively. the functions of Von Bertalanffy in H.molitrix was L_t=77.73[1-e^{-0.183(t+0.60)}],W_t=20 024.3[1-e^{-0.183(t+0.60)}]^3.027, and that in H.nobilis were:L_t=92.11[1-e^{-0.172(t+1.27)}],W_t=23 875.2[1-e^{-0.172(t+1.27)}]^2.946, the growth inflection points of H.molitrix and H.nobilis were 5.24 and 5 years old respectively. So it is recommended that the fishing age of H.nobilis and H.molitrix should be 5.5 years old respectively.

Abstract:In order to research the relationship between the morphological traits and body mass of Hexagrammos otakii, 150 tails of six-month and eighteen-month Hexagrammos otakii were randomly sampled for measuring body,mass and eight morphological traits including full length, body length, body height, body width, head length, trunk length, length of tail stalk, height of tail stalk, and correlation analysis, regression analysis and path analysis were used to study the eight morphological traits on the impact of the body mass.A significant positive correlation between morphological traits and body mass of six and eighteen months of Hexagrammos otakii were observed,with extreme significance(P<0.01),and the main morphological traits of body mass affected by different age of month were different. Six-month and eighteen-month Hexagrammos otakii were selected for the four morphological traits of body length, head length, body height, body width and full length, body height, height of tail stalk and body width by gradual introduction and gradual elimination method and the multiple regression equations were established:Y=-13.54+1.905X₂+1.222X₃+1.211X₄+1.499X₅, Y=-173.415+8.85X₁+11.18X₃+9.65X₄+20.749X₈. The results of path analysis showed that the morphological traits with the greatest direct effect on body mass of the 6-month-old and 18-month-old greenling were body length (0.706) and full length (0.538), respectively, and body length, head length, full length and body height had a decisive effect on the body mass of greenling at 6 months and 18 months.In addition to the morphological traits of the above, it should be combined with body width for breeding. The results of the study could provide important reference for the use of the morphological traits of Hexagrammos otakii for breeding.

Abstract:The research was aimed to compare the growth performance of wild megalopae (G0) and the offspring of wild broodstock (G1) of E. sinensis during the juvenile culture stage based on a culture experiment. The comparison and differences of body mass, survival rate, precocious rate, and the final yield are shown as follows:(1) No matter for females or males, the average mass of wild G0 was consistently lower than that of wild G1 individuals throughout the culture period with significant differences at 120-day and 150-day old of females (P<0.05); (2) The weight gain rate (WGR) and specific growth rage (SGR) of both populations were on the decline and they were generally higher in G1 individuals all through the culture stage except for the 150-180 and 180-210 days old. (3) The survival, yield and precocious rate of wild G0 were relatively higher than those of wild G1 individuals; (4) As for the size distribution of juvenile crabs, the body mass of wild G1 were mainly concentrated on the ranges of 0-4.00 g (36.76%), but the wild G1 were mainly concentrated on 4.00-5.99 g (26.93%) and 6.00-7.99 g (25.43%), the percentage large-size juveniles (≥ 12 g) were all low for both populations, only 8.46% and 7.60%. Wild megalopae were superior to the offspring of wild E. sinensis on survival rate and yield, and difference in nutritional value or immunity of both populations still needs further research.Through the culture experiment, the breeding effects of wild megalopae from two different sources in the juvenile culture stage were compared, which provided a practical basis for rational breeding and utilization of wild megalopae.

Abstract:Litopenaeus vannamei was used as main experiment object. Chronic enrichment was used to determine the effect of copper in different concentrations or dissolved forms during 56 days on immune active substances in Litopenaeus vannamei. The experiments were divided into five groups:one control group without Cu addition, two groups of different dosage of complexing Cu group and Cu addition group with which matched the complex Cu group released Cu. The LC6911 type corrosion-resistant alloy Cu was used as a complex Cu source, using 0.15 m² copper plate/m³ and 0.3 m² copper plate/m³ respectively, and the other two groups added matched amount CuSO₄·5H₂O as Cu²⁺ source. The following conclusions were drawn:(1) In the water of non-cultured, the experiments used LC6911 type corrosion-resistant alloy Cu tiled with 2 m³ aquarium barrel bottom. The total Cu released by copper plate was directly proportional to those area. (2) Immune proteins CP, POX,MT activities improved under two concentration gradients in experimental group, which was significantly higher than control group (P<0.05). (3) The enzyme activity of LZM in shrimp hemolymph was found in the experimental group of two different dissolved states. The results showed significant differences among control group and others at the end of the experiment (P<0.05). There was no significant difference between the two types of dissolved Cu and the different additive levels. And there was no significant difference in the LZM activity between the experimental group and the control group in gill tissue either (P>0.05). But the activity of LZM in Cu²⁺ group decreased significantly (P<0.05).(4)The long-term growth data showed that the growth effect of the experimental groups was not significantly better than that of control group, and the growth effect of the 0.15 m²Cu-plate/M3 group was the best. The enhancement of the immune activity and growth of Litopenaeus vannamei by complexing Cu in water is more prominent than Cu²⁺, meanwhile, using 0.3 m² copper plate/m³ in seawater has lower long-term toxicity effects on Litopenaeus vannamei's immune system.

Abstract:By using the method of experimental ecology, the water in the early stage of BFT aquaculture was used as the experimental material.The effects of bacteria free predators (protozoa etc., group AC), group with shrimp order supplemented with glucose (group GS) and single dose of glucose (group G) on bacteria and plankton in water were investigated. The results show that the biomass of rotifer, phytoplankton and concentration of chlorophyll-a in group GS were significantly higher than those in control group (P<0.05) in 120 h, while the biomass of rotifer and the phytoplankton in the group G had no significant difference from the control group (P>0.05) during the whole experiment (P>0.05), so the bottom-up effect of the sequential batch addition of glucose was more obvious than that of the one-off addition, and the top-down effect of group GS with large predators was not obvious. The total number of bacteria in the experimental group and the control group was higher than 5×10⁵ cells/mL. The highest peak number of bacteria was (13.10±3.79)×10⁵ cells/mL in group AC, which reduced the predation pressure on the bacteria and promoted the growth of the bacteria after removing the bacterial predator. The dissolved organic carbon concentration and dissolved total nitrogen concentration in the group AC were always higher than those of other groups. In the group GS, group G and the control group, the concentrations of dissolved organic carbon, total dissolved nitrogen and phosphate were basically consistent.Killing bacterial predator released a large amount of dissolved organic matter, adding appropriate amount of glucose, and adding shrimp had no obvious effect on the water quality of culture. Killing bacterial predator released a large amount of dissolved organic matter. Adding appropriate amount of glucose and adding shrimp had no obvious effect on the water quality of culture. The results provide the basis for control measures on sunshine biofloc-technology aquaculture in production.

Abstract:In order to explore breeding technology with the application of probiotics combinations for Penaeus vannamei under zero-water exchange conditions, four probiotic bacteria with different ecological functions were formulated to two combinations (i.e., PBE and PEN), which were applied in the breeding experiment from nauplius larval phase V (N5) to postlarvae phase V (PL5). Each experimental group contained six parallels and the control group was set at the same time. Culturing water was not exchanged throughout the experiment, and probiotics combinations were continuously applied to the water in the PBE and PBN groups. The larval metamorphosis rate, total culturable bacterial count (TBC) and total presumptive Vibrio bacteria (TPVB) in larva and water were counted at the phases of zoea Ⅲ (ZⅢ), mysis Ⅲ (MⅢ) and PL5. At the end of the experiment, the survival rate of postlarvae in each experimental group was determined, and the microbial communities from postlarvae were sequenced using an Illumina platform. The results showed that there was no disease outbreak in each group, and that probiotics combinations significantly decreased (P<0.05) relative abundances of TPVB in postlarvae and culturing water in the groups of PBE and PBN compared to that in the control group, and significantly increased (P<0.05) the larval metamorphosis rate (15%) and survival rate (15%) at the phases of ZⅢ and PL5, respectively. There was no striking difference of microbial diversities and structures of the core populations in the microbial communities from postlarvae in the three groups, and every microbial community was dominated by Rhodobacteriaceae with the relative abundance ranging from 40% to 86%. Taking together, probiotics combinations can effectively inhibit the overabundance of Vibrio in rearing-water and postlarvae and improve the survival rate of postlarvae, thereby achieving healthy breeding of P. vannamei under zero-water exchange conditions.

Abstract:In order to solve the problem of concentrated collection of pond sediment,a sediment collection device was designed. It mainly consisted of suction device, travelling mechanism, control system and floating pipeline. The suction device can lift the sediment to the bank by the sewage pump. The DC propeller of travelling mechanism provided power. The control system controlled the working state of the sewage pump and the two propellers to achieve normal operation of the device. Results of a series of tests on the mechanical properties revealed:The speed should be controlled within 0.1 m/s in working operation;Staying between 20-40 s, the fixed point of sediment can be completely sucked; The capacity of sewage suction was 0-14 m³/h; The mud content was 0-12.7 m³/h; The sediment concentration was 0-35%; The power of machine supporting was 0.9 kW;The idle running noise was 52 dB; the transmission distance was 100 m. The sediment device for pond culture used 220 V AC power is the power source. The power is isolated from the power grid by an isolation transformer, and then sent to the control platform of the sediment device for pond culture. It is high safety. The machine has the characteristic of large working area, which is conducive to the collection of pond culture sediment.

Abstract:This work aimed to appraise the role of dietary seaweed Sargassum thunbergii supplementation in the growth performance, body composition, and immune responsiveness of turbot (Scophthalmus maximus). A basal diet (without supplementation) was supplemented with increasing seaweed powder content to formulate five groups of experimental diets containing 0, 2.5%, 5%, 7.5% and 10% of seaweed powder (denoted as ST0, ST2.5, ST5, ST7.5, ST10 groups). Turbot juveniles (initial weight 66.45 ±0.52 g) were fed experimental diets for 8 weeks. Results showed that weight gain rate (W_GR) and specific growth rate (S_GR) tended to decrease with the increasing dietary content of seaweed powder, however, there was no significant differences between ST2.5 and control group (P> 0.05), and the other groups were significantly lower than the control group (P <0.05). The daily feed intake (D_FI) showed a gradually decreasing trend, among which ST10 group was significantly lower than control group (P <0.05). Dietary seaweed supplementation had no effect on feed conversion ratio (F_CR), survival ratio (S_R), viscerosomatic index (V_SI) and hepatosomatic index (H_SI). Crude protein content of whole fish tended to increase gradually, and crude fat content increased firstly and then decreased, however, both had no significant differences among groups (P> 0.05). Crude ash content increased gradually (P<0.05), which was consistent with the trend of crude ash content of feedstuff. The concentration of serum low density lipoprotein cholesterol (LDL-C) showed a trend of first increase and then decrease (P<0.05), and reached the highest value at ST5 group. Serum acid phosphatase (ACP) and catalase (CAT) activity increased first and then decreased, and also reached the highest value at ST5 group. Under the present experimental conditions, the addition of 2.5% S. thunbergii powder had no significant effect on juvenile turbot growth. Adding 5% S. thunbergii powder significantly increased the non-specific immune capacity of juvenile turbot.

Abstract:The pretreatment-ultrafiltration-reverse osmosis process was carried out in a pesticide enterprise to testify the operation performance. The results showed that COD_cr,TOC and the active ingredients of drugs removal efficiency were 98.90%,98.73% and 99% respectively, the water production rate was also more than 70%, which illustrated that this process was successful, and operated stably and reliably with high treatment efficiency. The water quality of effluent could meet the enterprise's internal control standard and this process had remarkable economic benefits and broad application prospect.

Abstract:In order to study the water environmental carrying capacity (WECC) of Xiangshan Bay in recent years, the thresholds of the water quality parameters DO, COD, DIN and DIP were obtained according to the statistics of Xiangshan Bay from 2010 to 2013. Then BP neural network technology was applied to establish a WECC model of Xiangshan Bay. The input of the model are the monitoring data of DO, COD, DIN and DIP. The output of the model was the Water Environmental Carrying Capacity Index (WECCI). The model was applied in the study of the WECC of Xiangshan Bay in the four seasons of 2014. The results show that:the seasonal-averaged WECCI of Xiangshan Bay in 2014 is always bellow 0.4, so the WECC of Xiangshan Bay is not ideal; The WECC of Xiangshan Bay is higher in the inshore than offshore area; The WECC is low all through the year in the bay mouth, influenced by the offshore water; The seasonal variation of WECC is complicated in the inner bay, and it is mainly locally influenced; The WECC in the central bay is high in spring, and low in summer, which is influenced by biological activity; The structure of BP neural network is simple, and the results are intuitive and reliable. Therefore, BP neural network could be used in the study of the WECC of Xiangshan Bay.

Abstract:In May 2013 (spring) and October 2013 (autumn), fishery resources were surveyed using a stern-trawling shrimp net in the Oujiang Estuary area of Wenzhou. A total of 12 stations were established. The survey data were standardized according to the swept area and escape coefficient at each station. Using the methods of relative importance index(IRI), hierarchical clustering(CLUSTER), non-metric multidimensional scaling(NMDS), ABC curve, etc., the community structure, spatial distribution and stability of shrimps and crabs in the waters of Oujiang Estuary were analyzed. The aim is to study the differences in the community structure of the spring and autumn of the Oujiang Estuary. The results showed that:The two surveys identified 25 species of shrimps and crabs, belonging to 11 families and 16 genera, 18 species in spring and 23 species in autumn; The number of species in the estuary area was lower in spring and autumn, and the nearshore and island reef areas were higher; There are three dominant species of Parapenaeopsis hardwickii, Acete schinensis, and Portunus trituberculatus in spring,and five dominant species of Exopalaemon carinicauda, Solenocera crassicornis, Portunus trituberculatus, Charybdis japonica and Scylla serrata in autumn. The ecological types show that shrimps and crabs are dominated by wide temperature, low salinity and wide temperature and wide salt species, and no cold water species were found. Cluster analysis divided the stations in spring and autumn into three communities. Non-metric multidimensional scaling (NMDS) shows that the clustering results in the spring and autumn are credible (0.05 ≤ Stress<0.1).The analysis of similarity (ANOSIM) showed that the differences between the communities in spring and autumn were significant and the significance levels were less than 0.05, and the results were acceptable. The analysis of SIMPER shows that the differences between the communities in spring and autumn are mainly determined by the difference of dominant species. The results of ABC curve analysis were in accordance with the actual conditions in spring and autumn. In spring, W<0,the community composition was dominated by small, low-quality species; In the autumn, W>0, the community composition was dominated by adults.

Abstract:Based on the purse seine statistical data of skipjack tuna in western and central Pacific Ocean during 1995-2014, 22 high catch fishing zone were selected, taking catch data as the index and combining different climatic conditions divided by the Nino index, to establish the forecasting model of Katsuwonus pelamisin western and central Pacific Ocean based on the different climatic conditions.The results showed that:the catch of skipjack fluctuated among different climatic conditions, the monthly total catch and monthly mean catch in El Nino were the highest, which was similar to La Nina, and higher than the normal condition; the catch among different spatial and climatic conditions had difference, the catch in 5°N was higher than 5°S, and the normal condition had the highest catch; La Nina event was the highest between the 145°E-165°E; La Nina was the lowest eastward of 165°E; the relationship between catch and SSTA of Nino 3.4 was established, and the above two indexes had strong relationship, fit well with the Normal Model (P<0.01). The model validation result showed that predicted results and actual results fitted well and had significant relationship in all the three climatic conditions. The spatial catch variation of skipjack tuna was analyzed under three different climatic conditions in western and central Pacific Ocean. The model can effectively provide new idea for the future work of fishing ground prediction and forecasting.

Abstract:GM (1, n) is established by the Spotted mackerel (Scomber australasicus) resources of the Pacific group which is supplied by Japan's central fisheries research institute from 1995 to 2012, combined with the sea surface temperature (SST) of spawning and feeding ground and tidal range. There are six models:GM(1,1) without environmental factor; four GM (1,2) models established by the SSTs of the feeding ground(140°E-160°E,35°N-50°N, SST1), spawning ground1(130°E-132°E,30°N-32°N, SST2), spawning ground2(138°E-141°E,34°N-35°N, SST3)and tidal range of Kuroshio; GM (1, 5) established by all the factors. The average error of each model is 6.72%, 3.73%, 4.41%, 4.78%, 29.56% and 19.38% respectively. The results show that the GM models based on feeding and spawning grounds temperature have a high accuracy in the spotted mackerel resource forecast, and can be used into more researches. By analyzing the gray parameters a and b, it is concluded that the SST2 and SST3 are the most restrictive to the model, which means the fluctuation of those factors had the greatest effect on the amount, and the temperature of spawning ground has a high correlation with the resources. When compared with the optimum temperature, it is presumed that the mackerel resources in the appropriate temperature range can increase with the temperature of the spawning ground. The global warming and gradual increase of SST are likely to have a positive effect on the spotted mackerel stock.