To establish a recombinase-aided amplification (RAA) assay for the detection of  Nocardia   seriolae , the primers for RAA were designed according to the specific genome fragments of  N.seriolae  with intraspecific conservation and interspecific variation. The specific primer of RAA was verified by detecting 7 related  Nocardia  spp. and 9 common pathogens in aquaculture, and the sensitivity of the detection method was analyzed by gradient dilution of the recombinant plasmid containing the target fragment. The reliability and coverage of the RAA assay were assessed in diseased and healthy fish as well as several  N.seriolae  strains from different sources. Results showed the RAA assay established in this study specifically detected  N.seriolae , and the detection sensitivity was 100 pg/μL. The positive bands were amplified in the tissues including liver, kidney, and spleen of artificially infected hybrid snakehead ( Channa   maculate ♀× C.argus ♂), and the  N.seriolae  strains of different sources. The finding indicates that the RAA assay established in this study is rapid and convenient and can meet the needs for the rapid detection of  N.seriolae .

In order to solve the using limitation of non - continuous lines among AutoCAD standard lines for ship graphing, some lines＇definition, like phantom and other non -continuous lines, are introduced in this article. The multi -line （five -line） definition way of trajectory is described in drawing for a boat.

According to the trend of worldwide environment protection, the paper discusses the end using time of some refrigerants, refrigerant replacement and transition, and recycling of prohibited refrigerants. Some proposals for refrigerant replacement in China are also given in the paper.

Artificial reef is an artificial facility used to restore and optimize the marine ecological environment and to build a habitat for marine aquatic organisms.It is also a basic ecological project in the construction of marine ranching.The selection and use of reef materials are directly related to the effect of artificial reef.From the six main categories of reef materials and the durability, environmental adaptability, biological affinity and economy considered in the use of materials, this paper summarizes the development status of materials used in the construction of artificial reefs at home and abroad, arranges and analyzes the characteristics and application effects of various reef materials of artificial reefs, and future development suggestions are put forward in the research, development and application of eco-friendly materials, new materials for resource recycling, carbon sequestration functional materials under double carbon goals and new artificial reef materials based on intelligent materials.It is expected to provide scientific reference for the selection of reef materials and the research and development of new materials.

In order to improve the accuracy of marine ship recognition in multiple targets and foggy environments, a marine ship recognition model SE-NMS-YOLOv5 is proposed based on improved YOLOv5 deep learning. The model is combined with Dark channel defogging algorithm, SE(squeeze-and-congestion) attention mechanism module and improved non-maximum suppression model for training and testing of ship data sets. The results showed that in the ship recognition task, there was the accuracy of 90.6%, recall rate of 89.9% and SE-NMS-YOLOv5  F 1 value of 90.5%, and compared with YOLOv5 model, the detection effect is improved by 6.3%, 4.8% and 5.8%. Compared with YOLOv4, the model improved 19.1%, 19.0% and 19.3%. In foggy conditions, the accuracy, recall rate and  F 1 value of SE-NMS-YOLOv5-Dark channel model were 88.1%, 87.2% and 87.6%, compared with SE-NMS-YOLOv5 model, the detection results are improved by 13.8%, 13.3% and 13.5%, respectively. The findings indicate that the marine ship recognition method based on SE-NMS-YOLOv5 effectively solves the problem of low accuracy of marine ship detection on multiple targets and foggy conditions, and improve the overall effect of ship detection and recognition.

Vibriosis as one of the main bacterial diseases in aquaculture, is causing harm to fish, shrimp, crabs, and shellfish, and development of its control techniques is of great significance for promoting sustainable development of aquaculture. The control methods of vibriosis mainly include drug, immune, and biological control, which are respectively represented by antibiotics, vaccines, and probiotics. Basing on the relationship between species, biological control is the method of inhibiting another organism or class of organisms by using an organism or class of organisms or their derivatives. It can carry out broad-spectrum disease control throughout the entire breeding process with little effect on the environment and food safety, which is a promising control technology. Currently, the biological control methods of vibriosis in aquaculture primarily include probiotics, medicinal plants, and bacteriophages. Based on the introduction of the etiology, epidemiology, pathogenesis and diagnosis of vibriosis in aquatic animals, we review the research on biological control of vibriosis in aquaculture animals from the aspects of control types, control mechanisms and applications of control technology. In addition, the main direction of future research on biological control of vibriosis is proposed: while deeply exploring its mechanism and mode of action, ensure environmental friendliness, high quality and efficiency, and promote its commercial development, thus to provide scientific reference for biological control of vibriosis in aquaculture.

Traditional methods of fisheries stock management decision-making have been developed since the 1950s to collect data and assess the status of stock, make scientific management recommendations and implement management measures through management measures. The disadvantage of traditional methods is that stock assessment often has large uncertainties, resulting in management recommendations that also have large uncertainties. Beginning in the 1980s and 1990s, with the development of computer simulation technology, the application of harvest strategy (management procedure) methodology in fisheries management has continued to develop, and has now evolved into a relatively mature and complete set of quantitative fisheries stock management methodology system, and plays an important role in the protection of marine mammals and the development and conservation of economic fish stocks. Comparatively speaking, the harvest strategy approach has been less applied and studied in China. This paper summarizes the basic process of traditional fishery resource management decision-making, as well as the characteristics, advantages and challenges of the harvest strategy approach, and proposes that the application of the harvest strategy is conducive to the scientific management and long-term sustainable use of fishery resources under the premise that specific management measures can be effectively implemented. With regard to fisheries that are considering the use of management strategy evaluation to establish harvest strategies, recommendations for future development are put forward, such as strengthening the collection of basic data on fisheries and population biology, strengthening research on population simulation techniques and capacity-building, and accelerating the development and application of new harvest strategies applicable to severely declining stocks, with a view to providing a reference for China in applying the harvest strategy approach to fisheries management decision-making.

In recent years, aquaculture activities cause severely impair to health of water body in nature as the rapid development of intensive aquaculture. During the aquaculture, fish faeces fail to be a properly handled and become the main contaminant which can destroy the water environment in aquaculture. The hazards coming from fish faeces to water body and farmed animals are summarized, the factors influencing fecal production and particles size under the condition of aquaculture are described, and several kinds of commonly measures from abroad and at home to prevent and control the hazards are discussed. The problems in management of water pollution in China, and a new outlook in the content of future research on faeces are presented.

In order to probe for fish community structure and biodiversity characteristics in north sea area of Zhoushan Island, the fishery resources and community structure including species composition, fauna characteristics, ecological groups, and biological diversity of fish were surveyed at 20 sampling sites in the north Zhoushan Island sea in spring (April, 2021), summer (June, 2021), autumn (October, 2020) and winter (Juanuary, 2021) by bottom trawls. Then the similarity of fish community structure was analyzed at different sampling stations in different seasons by clustering method. The results showed that a total of 50 fish species were collected and identified, belonging to 12 orders, 26 families and 45 genera, in the four seasons, with the descending order of the number of fish species in each season as summer>winter>autumn>spring. The fishes in this area were composed of warm water species (56.0%) and warm-temperature species (44.0%), with the dominant seasonal migratory species. The obvious seasonal change in dominant species was observed, with 6 species in summer, 2 species in spring, 1 species in autumn and 1 species in winter, and the most important dominant species being bombay duck  Harpodon   nehereus  in this area. The maximal diversity index ( H ′) was found in summer, the maximal evenness index ( J ) in spring, and the maximal richness index ( D ) in winter. There was the maximal similarity degree of community in summer and the minimal one in winter. The fish communities of four seasons were mainly represented by bombay duck and silver pomfret  Pampus   argenteus , with the different representative fishes in different communities. The fish community in the northern waters of Zhoushan Island was shown relatively stable in summer in recent 10 years, and the overall biodiversity level was slightly higher than that in the nearby waters.

The biological characteristics of bacterium Flavobacterium columnare were studied by Gram stain,colorimetry and agar diffusion methods.The bacterium cultured in broth Shieh meddium for 24 hours was showed different shape in the appearance including arch shape,U form,V form or S form and so on.Some of Flavobacterium columnare cultured for 72 hours appeared as branched cells and more granular involution form than that for 48 hours.The extracellular products（ECP） were found to be positive in the protease,lipoidase and lecithinase,but negative in amylase,gelatinase and urease.

Amyloodiniosis, commonly referred to as “marine velvet”, velvet disease, is a parasitological disease caused by one of the most common and important parasitic dinoflagellates  Amyloodinium   ocellatum . The  A.ocellatum  infects a wide range of fish species in different habitats including tropical and subtropical geographical locations, and has a direct life cycle that comprises three stages: trophont, tomont, and dinospores, which can be completed in less than a week dependent on favorable environmental factors. The disease is characterized by rapid onset and high mortality, which seriously hinders the healthy development of China’s marine fish industrial farming and semi-intensive pond farming, leading to huge economic losses. The typical symptoms of amyloodiniosis are changes in fish behavior, decreased appetite, faster breathing, and swimming at the water surface or gathering at the areas with higher dissolved oxygen concentrations. Fish mortalities are usually attributed to hypoxia, inflammation, severe gill hyperplasia, hemorrhage, and necrosis in heavy infestations. This review summarizes the current situation and the latest researches progress on the life cycle of  A.ocellatum , the prevalence, detection methods, and preventive and control measures of amyloodiniosis. It is proposed to strengthen the future research of pathogenic detection of the farming environment, low-temperature preservation, vaccine development, aiming to provide references for the scientific prevention and treatment of marine fish amyloodiniosis in fisheries production.

Hormones and their dosages are crucial in fish industrialized artificial propagation. In order to provide reference with economically important main fishes farming in China, we summarized the types and dosage of hormones used in induction to spawn in economically important main fishes (116 species in 12 orders) in China and the mechanism of artificial propagation and the methods and rules of hormone injection are discussed. Also, we probe into the research future on optimal hormones used in new variety farming, microencapsulation slow release technology and gene expression regulation.

To investigate the nitrogen removal capacity of different filler-biofilms in mariculture tail water, biofilters were constructed by the addition of oyster shells (M), coral stones (S), suspended ball fillers (F), elastic fillers (T), and without any filler as control (C), respectively. The formation speed and the biomass of biofilms as well as the nitrogen removal capacity of the biofilms at 24 hours were compared, while the changes in microbial community structure of the biofilms on biofilters were analyzed using Illumina Miseq high-throughput sequencing technology during biofilms formation period(20th day, 40th day, and 60th day). The different filler-biofilms were found to required 46-50 days for mature, with most rapid formation of the coral stone filler biofilm. Scanning electron microscopy showed that the biofilms on elastic filler and suspended ball filler had more biomasses than the other two fillers, largely consisting of rod-shape bacteria. The analysis of nitrogen removal capacity at 24 hours showed that there was the maximal removal rate of ammonia nitrogen and nitrate nitrogen by suspended ball fillers, and that the maximal removal rate of nitrite nitrogen by coral stone, which were (68.66%±6.27%), (6.73%±3.41%), and (99.99%±0.00%), respectively. The analysis of microbial community diversity revealed that the abundance of bacteria on elastic filler biofilms was increased, while the diversity of bacteria on oyster shell and coral stone biofilms was decreased significantly with the prolongation of biofilms formation time ( P <0.05). The dominant microfloras of biofilms with different fillers were shown to be Proteobacteria and Bacteroidetes at the phylum level. The relative abundances of Nitrospirae and Nitrospinae were increased with the extension of biofilms formation time.  Nitrosomonas ,  Nitrospira ,  Nitrospina  and unclassified_Nitrosomonadaceae were the dominant bacteria with nitrification on different filler-biofilms at the genus level. The descending order of relative abundance of nitrifying bacteria at 60th day was described as: suspended ball fillers (42.53%)> oyster shells (30.50%), elastic fillers (29.30%)> coral stones (11.74%)( P <0.05). The relative abundance of denitrification bacteria, such as  Pseudomonas ,  Ralstonia ,  Chitinophaga  and  Herbaspirillum , were higher on the biofilms of coral stone than on other filler-biofilms. The findings indicated that coral stone and suspended ball filler as ideal fillers were favorable to enrichment of nitrogen removal bacteria, and had better denitrification ability for mariculture wastewater.

A edge detection algorithm of biologic image based on dynamic and mathematical morphology, which can solve the affection of noise and blurring effect in image edge detection,is presented in this paper. The dynamic binary method was used firstly to define binary image threshold in transforming gray image to binary image. Secondly, the Erosion algorithm of mathematical morphology and de - empty method were used to eliminate noise of binary image. Finally the skeleton detection was used to detect image edge. The numerical experimental showsed that this algorithm reduced the effect of noise in image edge detection, and realized were accurately edge orientation, and hold adequately image detail. This algorithm is a good edge detection method in biologic image.

China is the largest of mariculture country in the world. The rapid development of this industry has brought about environmental pollution problems such as water pollutant discharge that cannot be ignored while booming the social economy. Mariculture wastewater is characterized by high salinity, complex pollutant composition and poor biochemical properties, and the treatment of mariculture wastewater is the difficult and technically demanding. Researches on the formation process and mechanism of mariculture carbon sink indicate that mariculture process and marine carbon sink are mutually reinforcing. This paper reviews the research progress of in situ bioremediation technologies including shellfish purification, microbial purification, biosymbiotic restoration, and comprehensive wastewater treatment, as well as ex situ bioremediation technologies such as ecological floating islands, ecological ditches, artificial wetlands, and ecological purification ponds. On this basis, the strategy of mariculture wastewater treatment and carbon reduction is proposed with the core of efficient deep treatment of wastewater and resource and energy recycling, taking into account the sustainable development goals of mariculture industry in China. The present paper looks forward to carbon neutrality in the future, innovating breeding models to increase marine carbon sinks, strengthening the management and control of green breeding processes, upgrading wastewater treatment technology and resource regeneration to reduce carbon emissions. The appropriate combination of carbon emission reduction is expected to provide a useful reference for promoting marine aquaculture to help achieve the strategic goal of carbon neutrality.

Oyster as a kind of marine shellfish with high nutrition, functional health care and medicinal value has great potential in the application of functional food production. Oysters are high in protein, rich in glycogen polysaccharides, zinc and other mineral elements, and have high nutritional value. Oyster peptides and polysaccharides have been proved to have a wide range of functional activities, such as anti-oxidation, anti-inflammatory, antihypertensive, anti-fatigue, anticoagulation, anti-tumor, and anti-liver injury. However, at present, the development and application of oysters in nutrition and functional food are very limited. This paper reviews the characteristics and nutritional value of oyster nutritional composition, as well as the research progress on the role of peptides, polysaccharides, zinc and other active functional components. In view of the research problems and development status of oyster in this field, the strategic prospect of research and development in preparation technology, functional activity improvement, factor deep mining, steady state, interaction and synergy mechanism is put forward, in order to provide reference for the further development and deep utilization of oyster resources.

The hemolytic activity and complement analogues AjC3, and AjC4 in coelomic fluid, the supernatant of coelomic fluid and coelomocytes were tested in sea cucumber Apostichopus japonicus by three methods. The results showed that there were complement analogues, AjC3, and AjC4 in the coelomic fluid, the supernatant of coelomic fluid and coelomocytes in the sea cucumber. The results indicated that an activity of complement analogues was present in the sea cucumber,and the activity of complement analogues was same as the activity of mammalian one. There was the maximal complement analogues AjC3, AjC4 in the coelomic fluid, followed by in the coelomocytes and the minimum in the supematant of the coelomic fluid.

Tuna ( Thunnus  spp.) as pelagic fish with fast swimming are widely distributed throughout the temperate and tropical epipelagic waters of the world’s oceans. They require a large amount of oxygen supply to generate energy for fast swimming via gills as the oxygen supply organ. Focusing on the morphology and function characteristics of the gills during rapid swimming in tuna, this review descries the morphological structure of gills, gills surface area, oblique blood flow pattern and thin water blood barrier thickness structure and oxygen supply characteristics of related research. Further, to elucidate the structural adaptation (gill fusion, calcification, lamellar arrangement of gills) of tuna gills to high-speed water impact and the characteristics of gills countercurrent exchange. The morphological structure and problems in the field of oxygen supply for tuna gills are discussed and some progresses are suggested including the early tissue development of tuna gills, function of gills cells, mechanism of adaptive evolution of gills by bioinformatics and the relationship between tuna gills physiological processes and environmental factors to provide theoretical reference for further studied on the molecular mechanisms of tuna gills.

To analyze the expression characteristics of  CgLOX 4 during larval development, the full-length cDNA sequence of  LOX 4 was amplified from Pacific oyster ( Crassostrea   gigas ) by using PCR, and the expression characteristics of  Cg LOX4 in different stages of larval development were further analyzed by qRT-PCR and whole-mount immunofluorescence experiments. It was found that the  CgLOX 4 gene had full-length cDNA sequence of 1 862 bp with an open reading frame of 834 bp encoding 277 amino acids, with the isoelectric point of 8.36. The amino acid sequence of  CgLOX 4 gene contained a conserved HOX domain, and  CgLOX 4 gene was expressed in all the tested tissues of adult oyster, with significantly higher expression level in the adductor muscle than that in hepatopancreas, gills, hemolymph, gonad and labial palps tissue ( P <0.05).  CgLOX 4 was expressed in all the examined early embryos, with relatively high expression level in fertilized eggs, and four-cells. The whole-mount immunofluorescence assay revealed that the positive signals of LOX4 were mainly distributed in the shell field of trochophore, the visceral mass of D-shape larvae and the digestive gland of umbo larvae. The findings indicate that  CgLOX 4 gene is one of the transcription factors activated earlier in the early development process of the oyster, and may play an important role in regulating the formation of larval shell and digestive organ.

The purpose of this experiment is to investigate the dietary stickwater hydrolysate (SWH) and plant essential oil on growth performance,immunity,digestive enzyme activity and TOR related gene expression of juvenile turbot  Scophthalmus   maximus  fed low fish meal diets.Juvenile turbot with initial body weight of 37.67 g were reared in a closed water circulating system and fed diets containing 50% fish meal (D1,positive control),and containing 30% fish meal (D2,negative control),and 30% fish meal diets supplemented with 1% SWH (D3),0.02% plant essential oil (D4),and 1% SWH+0.02% plant essential oil (D5) with triplication at water temperature of (16±1)℃ for 8 weeks.The results showed that there were significant increase in weight gain rate,specific growth rate and protein efficiency ratio and significant decrease in feed conversion ratio in the turbot in D3 group ( P <0.05).The maximal activities of serum lysozyme was observed in the turbot in D5 group ( P <0.05),significantly higher than that in the D2 group ( P <0.05),without significant difference from D1 group( P >0.05).The turbot in D5 group had the minimal C3 content,significantly lower than that in other 4 groups( P <0.05).The maximal intestinal trypsin activity was found in the turbot juveniles in D3 group ( P <0.05),significantly higher than that in the D2 group( P <0.05),without significant difference from D1 group ( P >0.05).The maximal  TOR  mRNA expression level was observed in liver of fish in D3 group,significantly higher than that in the D2 and D1 groups ( P <0.05),with an opposite trend in 4 EBP 1 and 4 EBP 2 mRNA expression levels ( P <0.05).There was significantly lower cumulative mortality of juveniles exposed to  Vibrio   anguillarum  infection at a dose of 7.94×10 5  CFU/g for 48 h in D4 and D5 groups than that in D2 group ( P <0.05).It can be concluded that supplementation of 1% SWH led to significantly enhance the growth performance,trypsin activity,liver TOR related gene expression level of turbot,and that 0.02% plant essential oil to significantly enhance the ability of fish to resist  V.anguillarum  infection.However,the combination of 1% SWH and plant essential oil does not result in good effect instead of low weight gain,the mechanism of their interaction needs further research.

The effects of fourweaning foods including soybeanmilk,egg yolk,fairy shrimp and rotifers enriched by green alga Chlorella vulgaris on growth performance and body composition of larval bulatmai barbel Barbus capito were investigated in order to explore the optimalweaning food of bulatmaibarbel larvae.The results showed that the fish had increase in body weight and body length since 14 days post hatching(DPH)with the best growth in the fish fed rotiferswhich showed higher survival rate,bodyweight,and body length than those in the fish fed the other foods on 14 DPH,19 DPH and 24 DPH.There were 16.45％of protein and 8.79％of fat in the fish fed rotifers. The fish fed fairy shrimp had body weightof1545.2mg,body length of22.509mm and survival rate of88.7％on 24 DPH,significantly higher than those in the fish fed egg yolk and soybean milk.The larvae had good growth by 14 DPH,and seldom grew later when they fed egg yolk.Theminimal growth and survival rates were found in the fish fed soybeanmilk.The findings indicated that rotifers enriched by Chlorella vulgaris wasmost suitable as aweaning food,and that the key point for initial feedingwas of14 DPH in bulatmaibarbell larvae,egg yolk being used as a supplement food before 14 DPH.

In order to explore the effects of addition of green alga ( Chlorella   vulgaris ), bacterium ( Bacillus   subtilis ) and mixture of  C.vulgaris  and  B.subtilis  on aquatic environment, growth performance and related enzyme activities of largemouth bass ( Micropterus   salmoides ), juvenile largemouth bass with body weight of (11.71±0.90)g was reared in a 1 000 L polyethylene barrel filled with 800 L water added with  C.vulgaris  (density of 1×10 9  cells/L at 6.25 mL/L)(alga group),  B.subtilis  (1×10 11  CFU/g at 0.75 mg/L) (bacterium group), both  C.vulgaris  and  B.subtilis  (bacterium + alga mixture group), and blank (without any bacterium and alga, control group for days). The results showed that there were generally optimised physical and chemical indices in the water environment in the alga group and bacterium group during the experiment, compared with the blank group, with the relatively small differences in the total nitrogen, total phosphorus and dissolved oxygen contents in each experimental group, while there were considerably varied in the contents of ammonia nitrogen, nitrate nitrogen and nitrite nitrogen, especially in the water environment in the bacterium + alga mixed group, with the minimal ammonia nitrogen, nitrate nitrogen and nitrite nitrogen contents in water in most time points ( P <0.05). At the end of the experiment, the largemouth bass in all experimental groups had increase in body weight, weight gain rate, and specific growth rate compared with the blank group, with significant differences in only the bacterium + alga mixture group compared with the blank group ( P <0.05). The hepatic glutathione (GSH) content, and activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) and lysozyme (LZM) in general were shown to be significantly increased ( P <0.05), and malondialdehyde (MDA) content to be significantly decreased ( P <0.05), especially in the bacterium + alga mixture group compared with the blank group. To sum up, it can be seen that addition of either  C.vulgaris  or  B.subtilis  to the water environment can improve the water quality, promote the growth and hepatic antioxidant capacity and immunity in largemouth bass, and addition of both the green alga and bacterium at the same time is more effective.

This paper presents basic principle and structure including the advantages,and disadvantages of the optic fibre gyro compass.The developing process of the fiber optic gyro compass was described and the forecast to the future application prospect was carried out.Meanwhile the errors and the precision factors affecting the optical fiber gyro compass were analyzed.The measurement to decrease the errors was put forward.

Industrial recirculating aquaculture has become one of a new culture model for transformation and development of aquaculture industry. Particularly, optimization of the aquaculture tank environment is the key to realize the healthy cultivation of fish and other aquatic animals. It is proposed to increase the research on the hydrodynamics of aquaculture tanks and the integrated application with the key technologies such as structural design and optimization, and to carry out hydrodynamic research based on cultured animals, so as to provide a reference with the development of recirculating aquaculture. The research methods and problems of the current hydrodynamics in recirculating aquaculture system are reviewed including flow field in aquaculture tank, collection and discharge of solid particles, diffusion and transport of soluble and suspended pollutants, aeration performance, and interaction between fish and flow field, aiming to establish an efficient green aquaculture model with friendly environment, high water quality, resource saving and animal health, and high quality and high yield of aquatic products.

In order to understand the composition and structural characteristics, spatiotemporal distribution pattern and key impact drivers of phytoplankton communities in the Yangtze River Estuary, the characteristics of phytoplankton communities and the relationship between the characteristics of phytoplankton communities and influencing factors were explored based on the survey data of phytoplankton in the Yangtze River Estuary in August (summer) and November (autumn) from 2018 to 2020 by community diversity analysis indicators and generalized additive model (GAM). The results showed that a total of 185 species of phytoplankton were collected in 8 phyla, 99 genera, with the dominant species mainly including  Skeletonema   costatum ,  Aulacoseira   granulata ,  Melosira   sulcata ,  Cyclotella  sp. and  Chlamydomonas  sp., and the main phytoplankton groups including Bacillariophyta, Cyanophyta and Chlophyta, in which  Skeletonema   costatum  had long been overwhelming. There were significantly higher abundance and species of phytoplankton in summer than those in autumn ( P <0.05). In autumn, however, phytoplankton communities showed higher diversity index and richness index and more evenly distributed. Spatially, the average phytoplankton abundance showed the distribution pattern of East Beach >South Branch >North Branch as a whole. The GAM analysis indicated that water temperature (Tem), pH and total nitrogen to total phosphorus ratio (TN/TP) were the environmental factors ( P <0.05) significantly affecting the abundance distribution of phytoplankton in the Yangtze River Estuary in summer, with the maximal contribution rate of 71.86% from TN/TP. Salinity (Sal), dissolved oxygen (DO) and chemical oxygen demand (COD Mn ) were found to be the environmental factors ( P <0.05) significantly affecting the abundance distribution of phytoplankton in the Yangtze River Estuary in autumn, especially the DO contribution up to 48.48%. The findings indicate that there are seasonal differences in the community composition, structure, pattern and influencing factors of phytoplankton in the Yangtze River Estuary, which provides references for understanding of the dynamics of phytoplankton resources in the Yangtze River Estuary.

Fish eggs could be classified into three categories: adhesive, weakly adhesive and non-adhesive, depending on degree of egg adhesiveness. Many commercially important fish spawn as adhesive eggs, and upon contact with water, the outer layer of the chorionic membrane becomes hydrated, and the adhesive substance subsequently becomes activated and sticky. The adhesiveness of eggs is a huge challenge to artificial incubation and breeding technology, and thus the researches on the characteristics and the mechanisms of adhesive eggs are of great significance to the artificial reproduction of fish. Here we reviewed the latest research progress and developments on characteristics and mechanisms of adhesive eggs, and we also compared the effects of various reproduction methods in different fishes. Furthermore, the future and multiple potentials of artificial incubation and reproduction technologies in fishes that produce adhesive eggs are discussed to provide reference for the artificial breeding of adhesive eggs-spawning fishes.

Streptococcus   agalactiae  as one pathogen in tilapia has brought huge economic losses to the tilapia breeding industry due to strong contagiousness and high mortality by the pathogen. This pathogen infects tilapia by different pathways, including cohabitation, oral route, immersion, intraperitoneal and intramuscular inoculation, and is capable of replicating in tilapia bloodstream, penetrating the blood-brain barrier into brain, resulting in meningitis, and passing through the mucus layer of both the stomach and intestine and finally adhered, colonized and invaded the gastrointestinal epithelium, leading to typical histopathological changes, including meningitis, epicarditis, hemorrhage in renal interstitium, multifocal necrotizing splenitis and septicemia in tilapia. The most frequent clinical symptoms of affected tilapia are erratic swimming, exophthalmia, hemorrhage at the operculum, pectoral, and ventral areas and rapidly progressing mortality. Traditional diagnosis methods for the detection of  S . agalactiae  in the host tissues are based on bacterial culture, and DNA-based methods including PCR and loop-mediated isothermal amplification are increasingly used. Molecular typing of  S . agalactiae  strains has been performed by different methods, such as molecular serotyping, amplified fragment length polymorphism, multiple-locus variant-repeat assay, and pulsed field gel electrophoresis, multilocus sequence typing. Virulence genes have faster mutation rates and higher polymorphism than housekeeping genes, and the multi-virulence locus sequencing typing method can be widely used to evaluate genetic variation in  S . agalactiae . At present, aquaculture depends on antibiotics to treat or prevent  S . agalactiae  disease in tilapia. Although these antimicrobials have some benefits, the abuse of antibiotics occurs during tilapia production, leading to the development of antimicrobial-resistant strains. Although vaccination is an alternative method to control streptococcal diseases, few commercial vaccines are currently available for treatment of  S . agalactiae  disease in a large scale tilapia production. This paper comprehensively summarizes the latest research progress and development trends in etiology, epidemiology, pathology, pathogenic mechanism, detection methods, molecular typing, antibiotic resistance and vaccines of  S . agalactiae  in tilapia. The current problems that need to be solved are discussed and valuable measurements are suggested for the prevention and control of  S . agalactiae  disease in tilapia.

Histopathological, haematological and toxicological effects of malachite green （MG） on various animals, and the biotransformation of malachite green （MG） and its matabolites, leucomalachite green （LMG） were summarized. The recent research advances on determination of malachite green and leueomalachite green were dewed abroad. Alternative disinfectants to malachite green were advised. An approach to remove excess malachite green from treatment water should be explored.

The biological characteristics of albacore Thunnus alalunga,including body length frequency,sex ratio,and food were analyzed by the data collected by Chinese tuna longline operation in the southern and central Indian Ocean from September of 2008 to April of 2009.The results showed that the fork length（LF） ranged from 74 to 120 cm with predominant 105-110 cm（47.8%）,and with mean LF of（107.2±4.99） cm.The relationship between fork length and dressed weight（WD） for both sex of albacore can be expressed as WD=1.7146×10-5L3.0197F for female,WDM=7×10-5L2.7229FM,and WDF=2×10-6L3.5354FF for male.The gonads were mainly developed into stage IV（about 43.1%） during the survey.The stages 0 and 2 were found in feeding stages for the fish with fork length of below 100 cm,most（over 39%） of which had empty stomach.The fish with fork length of 100-120 cm,however,had an increase in the stomach fullness,and a decrease for the fish with fork length of 91-110 cm and 111-120 cm.

With the continuous decline of global fishery resources, fishery agencies and regional fisheries management organizations of various countries use the fishery observer method to promote sustainable fishing, but the human observer method is characterized by so high cost and low coverage as to difficult to meet the management needs. In recent years, detection speed and accuracy have been continuously enhanced due to continuous emergence and improvement of new deep learning algorithms, thus providing conditions for marine fishery fishing production monitoring. The process of building a fishery production monitoring model is introduced from the aspects of data acquisition, data preprocessing, algorithm design, model training, and model accuracy evaluation. The application of deep learning technology in marine fishery fishing is discussed, and methods such as transfer learning or reinforcement learning are proposed in terms of fishing boats and boat behavior, catches, fishery forecasts, crew members, and fishing gear to expand the identification of target species and enhance detection algorithm，and use high-accuracy feature extraction network to improve the accuracy of target classification, to solve the real-time analysis of electronic monitoring data through edge computing technology and to formulate standards and specifications for electronic monitoring fishery management applications and other key research directions in the future, which provides reference for the promotion of deep learning in marine fishery fishing production.

The adaptability of juvenile prawn Macrobrachium nipponense to different salinities was determined under artificial cultural condition. The mean mortality time （MST） was found to be 19.63, 6.63, and 2.93 h at a salinity of 32, 34, and 36 for the prawn, respectively. At a salinity of 30, 32, 34, and 36, the median mortality time （ST50） was 26.67, 11.27, 2.60, and 1.53 h, respectively, and the median lethal salinity （MLS） 30.71, 26.66, 26.31, and 25.80 at 24, 48, 72 and 96 h. The maximal growth in body length and body weight was observed at a salinity of 12, indicating the juveniles had high tolerance to salinity and was cultured at high salinity area of waters.

The sustainable use of fishery resources is a key issue in the sustainable development of fisheries, so in order to ensure the maximum sustainable use of fishery resources, it is necessary to evaluate the development potential of fishery resources. The research on evaluation of the sustainable use of fishery resources is systematically organized and analyzed by using the Core Collection of Web of Science and the CNKI database to retrieve 229 and 238 documents, respectively, internationally and domestically, using the documentary econometric analysis method based on citespace software, and combined with keyword network knowledge map and mutation detection, the sustainable use of fishery resources evaluation of research hot spots and future trends are explored. The overall fluctuation of the research volume of sustainable use of fishery resources showed an upward trend, with more research in this field in the United States, China and Canada. At present, the research hot spots include the evaluation methods and strategies of sustainable use of fishery resources, the impact of climate change on fishery resources, the evaluation of sustainable use of fishery resources based on ecosystem management, and the management system of sustainable use of fishery resources. The key research directions are put forward in the future including the problems in the study of sustainable utilization of fishery resources, such as the improvement and unification of evaluation methods and the supervision and perfection of management systems.

The paper introduces the researching results of shellfish aquaculture and purification in Jinbei Square. Several tests has been done such as aquaculture density, circulating water volume, aerating pattern, water temperature and oxygen consumption, oxygenation capacity, circulating water quality, death of halting electricity etc. The results indicate that it is suitable for the aquaculture density to be less than 0.3 kg/L, aerating oxygenation patterns to be aerating outside the tanks, aquaculture temperature to be 6℃, shellfish＇s activity to be normal when dissolved oxygen is over 3.7 mg/L, the circulating frequency to be more than 3 per day, and halting electricity to be less than 3 h.

In order to explore possibility of freshwater mussel  Solenaia   oleivira  culture in coastal NaCl saline alkali land or tidal flat, the survival test was carried in the freshwater mussel juveniles with wet body weight of (2.63 g± 0.47 g) exposed to acute stress of fresh water (0.20) and high salinity of 2.00, 3.31, 3.70, 4.24, 4.92, 5.82, and 7.00 using the equal log interval method and 50% of the 96 h half lethal salinity (LC 50 ) as the tolerant salinity. The oxygen consumption rate, ammonia excretion rate, food intake rate and fecal excretion rate were measured in freshwater mussel exposed to these salinities by the indoor hydrostatic method, and then the energy budget equation was established at water temperature of (22±1)℃. The results showed that the dead mussel was observed at salinity of 2.00 at 72 h, and at salinity of 7.00 within 48 h, with LC 50  of 4.47 at 96 h. There were significantly higher oxygen consumption rate, ammonia excretion rate, food intake rate, water filtration rate and fecal excretion rate ( P <0.05), with the decreased slightly lower absorption efficiency ( P >0.05), in the juveniles at stress of high salinity (2.23) than those in the freshwater mussel in the fresh water group ( P <0.05). Under high salinity (2.23) stress, the freshwater mussel had significantly higher energy used for respiratory metabolism and feeding metabolism, with increase in the proportion of respiratory energy ( R ), excretory energy ( U ) and fecal energy ( F ) in feeding energy ( C ), and significant decrease in the proportion of growth energy ( P ) in feeding energy. The energy budget equation was described as 100 C =57 . 22 R +9 . 49 U +9 . 05 F +24 . 23 P  under fresh water and 100 C =62 . 55 R +13 . 99 U +12 . 05 F +11 . 41 P  at high salinity (2.23) stress. The finding indicates that the juvenile firewater mussel  S.oleivira  has a poor tolerance to sodium salt which shows a significant impact on the respiratory metabolism and food metabolism of the mussel. The coastal NaCl type water is within saline alkali land or tidal flat water where the juvenile freshwater mussel culture should be at a salinity of less than 2.23.

The recombinant cDNA of Tilapia Hsp70 was amplified from blood mRNA and inserted into vector pMD18-T.Sequencing revealed that the cDNA was subcloned into expression vector pPIC9K.The recombinant vector was transformed into the yeast Pichia pastoris KM71 via electroporation after sequencing.The transforming positive clones were screened by PCR and rtHsp70 in culture supernatant induced by methanol was identified by Western blot.Protein purification by the affinity chromatograph and gel filtration showed the sequence of rtHsp70 DNA was correct.It was a protein with relative molecular mass of 70 000 in the culture supernatant by SDS-PAGE and Western blot analysis.Two 2 mg purified rtHsp70 can be obtained in per liter expression supernatant,and Pichia pastoris engineer bacteria of rtHsp70 expression and purified protein were gained.The study is paved the way for further study of using rtHsp70 for immunologic adjuvant in peptide-vaccine application.

 To construct a polar ratio fluorescent probe for accurate detection of biological microenvironment, the probe IA based on naphthalene ring fluorophore was firstly synthesized by introducing malononitrile and N, N-dimethyl group on acenaphthene ketone, and then the polarity responsive ratio fluorescent probe IAN was synthesized by condensation reaction of IA amino group into heterocycle. The molecular structure and mass of probes IA and IAN were characterized by  1 H NMR,  13 C NMR and HRMS, and then the absorption and fluorescence spectra of probes IA and IAN in different polarity solvents were examined and compared by UV-Vis and fluorescence spectrophotometer. The results showed that IA exhibited single absorption and fluorescence emission peaks and fluorescence intensity of IA was gradually enhanced with solvent polarity increasing. Differently, double absorption and fluorescence emission peaks of IAN were simultaneously detected in solvents ( λ em =474 nm, and 552 nm), and the fluorescence intensity ratio  I 474 nm / I 552 nm  produced a sensitive Boltzmann function response to solvent polarity changes. Compared with IA, IAN was able to respond accurately to environmental polarity changes as a ratio fluorescent probe. The fluorescence intensity of the lesions was shown to be significantly lower than those of the healthy tissues by using IAN on mice with breast cancer and grouper hybrid  Epinephelus   fuscoguttatus ♀× E.lanceolatus ♂ with hepatobiliary syndrome. These findings indicated that amino group undergoing a condensation reaction to generate a heterocycle containing nitrogen atom increased the conjugation degree of lone pair electrons of the nitrogen atom to the π system, so that the probe IAN produced n→π *  and π→π *  molecular transition at the same time, and then enabled the construction of a ratio fluorescent probe responding sensitively to polarity changes.

To investigate the effect of fucoxanthin on blood glucose and possible mechanism in type Ⅱ diabetic mice, the blood glucose and lipid metabolism related indices were determined in the type Ⅱ diabetes model mice established by streptozotocin (STZ). The type Ⅱ diabetes model mice was gavaged with fucoxanthin extracted from seaweed ( Sargassum   horneri ) at a dose of 25, 50 and 100 mg/kg and the inhibition effect of fucoxanthin on α-glucosidase was investigated, and the pathological changes were observed in liver tissues of the mice by Hematoxylin-Eosin (HE) staining. The mRNA relative expression levels of cellular PI3K/AKT signaling pathway indicators including phosphatidylinositol 3-kinase (PI3K), and protein kinase B (AKT), glycogen synthase (GS) and glucose transporter 4 (GLUT4) were detected by fluorescence quantitative PCR. The results showed that the fucoxanthin had inhibition rate of 76.43%±0.83% on α-glucosidase, with the noncompetitive inhibition type, resulting in significantly decrease in the levels of fasting blood glucose (FBG), insulin (INS), total cholesterol (TC), triglyceride (TG) and low density lipoprotein (LDL-C), and in increase in the content of liver glycogen and high density lipoprotein (HDL-C) in the diabetic model mice. Histopathological observation showed that the infiltration of liver inflammatory cells was relieved by the fucoxanthin. There was increase in the mRNA expression levels of  PI 3 K ,  AKT ,  GS  and  GLUT 4 mRNA in diabetic mice orally administrated by fucoxanthin. The findings indicated that fucoxanthin regulated blood glucose in mice through PI3K/AKT signaling pathway with dose-dependent relationship, and the best hypoglycemic and hypolipidemic effects was at 100 mg/kg.

In order to investigate the mechanism of the response of scalloped spiny lobster  Panulirus   homarus  to nitrite stress, the transcriptomics were comparatively analyzed in hepatopancreas of scalloped spiny lobster with body weight of (39.00±5.31)g exposed to under normal conditions   <0.01 mg/L, control group)and to 80 mg/L nitrite stress prepared by NaNO 2  for 7 d by a transcriptomic sequencing approach. The results showed that 264 differentially related genes were screened, with up-regulated 86 and down-regulated 178. GO functional annotation results showed that the annotated differential genes were primarily involved in functions including binding, catalysis and metabolism, and KEGG pathway enrichment analysis showed that the differentially expressed genes were significantly enriched in focal adhesion, leukocyte transendothelial migration, insulin resistance, tight junctions, and starch and sucrose metabolism pathways. Nine differential genes were randomly selected for qRT-PCR validation, and the fluorescence quantification results were found to be in general agreement with the sequencing results. The findings will provide substantial reference for the research of gene functions in energy metabolism, growth and immunity in scalloped spiny lobster under nitrite stress.

Koi carp Cyprinus carpio with initial body weight of(195.88±0.98)g was fed three kinds of diets,Japanese commercial diet(as control)and the diets containing growth-promoting additive complex(L-carnitine, blood-cell protein meal,Spirulina powder and Bacillus subtilis powder),and pigmentation-promoting additive complex(astaxanthin,spirulina and Bacillus subtilis)at water temperature of(25±1)℃for 60 days with triplication to investigate effects of different additive combination in diets on growth and body pigmentation of koi carp. Growth performance and body pigmentation of koi carp were determined every 15 days during the 60 d experimental period.Results showed that the koi carp fed the diets containing growth-promoting additive complex and Japanese commercial diets showed similar growth performance,with lower food conversion ratio than the koi carp fed the Japanese diets.The diets containing pigmentation-promoting additive complex led to improve the body pigmentation of the red and white koi carp,which is comparable to the koi carp fed the control diets.The similar degree of pigmentation was observed in the koi carp fed both experimental pigmentation diets,indicating that the two experimental diets with different feed additive combination have the equivalent effects with Japanese commercial diets and that can match the standard in promoting the growth and body pigmentation of koi carp.

Juvenile Russian sturgeon Acipenser gueldenstaedti with initial body weight of 29.70 g±1.32 g were reared in nine square concrete ponds(4.4 m×4.4 m×0.6 m)at stocking density of 2.5 kg/m3(80 ind./m2) (SD1),3.6 kg/m3(115 ind./m2)(SD2),and 4.7 kg/m3(150 ind./m2)(SD3)for 90 days with triplication to investigate the influence of stocking density on hormone,physiological and biochemical components of the juvenile. Cortisol levels were shown to be elevated in the Russian sturgeon reared for 50 d in the experimental groups,significantly higher in the fish reared for 90 d in group SD3 than in SD1 group and SD2 group(P＜0.05).The hemoglobin content was found to be significantly and positively correlated with the stocking density(P＜0.05).There were significant differences in leukocyte contents at different stocking densities of Russian sturgeon(P＜0.05),significantly higher white blood cell count in the juvenile Russian sturgeon in group SD3 than those in group SD1 and group SD2(P＜0.05),indicating that the long-term high-density culture of the Russian sturgeon led to physical and pathological damage of the fish by the end of the experiment.The Russian sturgeon juveniles showed a tendency of blood-sugar levels upgrade first then descending,significantly lower in group SD1 than in group SD3 and group SD2(P＜0.05).There were no significant differences in levels of total cholesterol and total protein(P＞0.05).At the end of the experiment,the juveniles had significantly higher blood triglyceride content in group SD3 than the juveniles in group SD1 did(P＜0.05),without significant difference between group SD1 and SD2.The findings indicate that the order of energy utilization in Russian sturgeon was expressed as blood sugar＞serum protein＞blood lipid.