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.

The sushi-grade evaluation technology and indicators are constantly developing, and the establishment of scientific and efficient evaluation methods is more and more urgent with the continuous improvement of the demand for high seafood.This paper focuses on fresh products, and systematically reviews the development of seafood quality evaluation from two aspects: indicators and methods.Firstly, the scientific origin of freshness evaluation and the construction process of traditional fishery product evaluation technology system are reviewed systematically from sensory evaluation and non-sensory evaluation methods, and the research progress of live product quality evaluation in recent years is described.Then, systematic analysis and emerging technologies and their corresponding indicators are discussed with modern analytical techniques as the focus.The analysis and summary centering on the evaluation system of traceability, varieties and sushi-grade are analyzed through modern analytical techniques such as chromatography, mass spectrum and spectrum, combined with Omics technology.Finally, from basic theory research on raw material to learn, the defects of the traditional consumption mode, and upgrade the existing domestic consumption and demand three aspects, the sushi-grade for the study of the importance and necessity of breakthrough point and the corresponding quality index and key real-time analysis technology is put forward to provide some reference for the application and development of fresh seafood evaluation indices and methods to promote fishery product-processing industry upgrading.

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.

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.

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.

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.

Since low temperature is one of the main environmental factors affecting production and survival of shellfish, the research of mechanisms and tolerance to low temperature in shellfish has very important role in shellfish breeding industry. In this review, we summarize the progress in the field of the resistance and tolerance to cold stress in shellfish in recent years, focusing on research results of shellfish responding to low temperature stress, and effects of low temperature on physiological and biochemical characteristics of shellfish, including changes in energy budget, body composition and enzyme activities of shellfish under low temperature. The response of cold responsive genes in shellfish to low temperature is described, including the expression changes in cold shock proteins gene, heat shock proteins gene and antioxidant enzyme gene under low temperature stress. On this basis, the prevention and control measures of shellfish in response to low temperature environment are discussed and new perspectives and information on future research and practice in this field is put forward.

This paper summarizes the progress on principle and technology of high - density rotifer in mass culture method in Japan. There are at least 100 times more efficient in Japanese mass rotifer culture method with less cost for production than that in the conventional method. Firstly, condensed freshwater Chlorella is employed as new food for rotifers instead of bakery yeast and Nannochloropsis. Secondly, cultures were generally supplied with constant O2 to avoid oxygen deficiency. Thirdly, pH was adjusted to 7 by automatic addition of HCl to promote the dissociation of NH3 to NH4^＋ and OH^-. Fourth, the excess suspended organic matter can be efficiently romoved by a nylon filtration mat. Fifth, addition of a defoamer substance can prevent the culture water from loss and from rotifer attachment to the foam. Using these techniques, the rotifer culture density increases to 20 000 ind. /mL. Recently a novel culture system using a continuous membrane filtration unit （CMFU） for ultra -high -density culture is developed in Japan. In this culture system NH4^＋ and soluble organic substances are removed by the culture liquid, with rotifer density of 160 000 ind. /mL.

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.

The effects of fourweaning foods including soybeanmilk,egg yolk,fairy shrimp and rotifers enriched by green algaChlorella vulgarison growth performance and body composition of larval bulatmai barbelBarbus capitowere 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 byChlorella vulgariswasmost 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.

 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 1H NMR, 13C 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 (λem=474 nm, and 552 nm), and the fluorescence intensity ratio I474 nm/I552 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.

Astaxanthin of Antarctic krill as a huge bioresource, still deeply undeveloped and unutilized marine living resources is a natural antioxidant with great antioxidant activities, and particularly, plays an important role in the body color change and the improvement of immunity of fish. In this article, the advances of preparation methods (solvent extraction method, enzymatic hydrolysis method, and supercritical carbon dioxide extraction), structure characteristics, bioactivities, detection methods (ultraviolet spectrophotometry, thin-layer chromatography, laser Raman spectrometry, high efficiency liquid chromatography and high performance liquid chromatography -tandem mass spectrometry) of astaxanthin from Antarctic krill are reviewed, and future suggestions on mechanism researches, key technologies and product developments of Antarctic krill astaxanthin are put forward. It is anticipated that contribute the deep research and utilization of Antarctic krill astaxanthin in the future.

Protease activities were determined in different parts of digestive organs in largemouth bass （Micropterus salraoides） at different temperature, pH and casein concentration by means of enzymological analysis. The results showed that the protease activities in different parts of digestive organs were arranged in a descent order as： stomach 〉 pyloric caeca 〉 foregut 〉 midgut 〉 hindgut. The protease activities changed with variations in temperature, pH and casein concentration in different organs. The optimum temperatures and pH were （40℃, 2.4 ） for stomach, （55℃ ,7.6） for pyloric caeca（45℃ ,8.0） for gut. The optimum temperature for protease activity was higher than that in the fish body. The highest activity of protease occurred in strong acidic condition in stomach, but in neutral or weak alkaline condition in pyloric caeca and gut. The activity of the protease also changed with concentrations of the casein, the optimum casein concentration of 20 g/L for stomach. 20 g/L for pyloric caeca, and 10 g/L for gut.

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.

Fish behaviors as well as feeding, reproduction and respiration include other acts including evading predators, migration, clustering and are affected by some environmental factors such as tide and water temperature. This paper summarizes the main fish behavior research methods, and application in fishing as the future main developmental trend is based on the characteristics of different fishes and development of highly efficient energy - saving and environment- friendly fishing gears. Thereby, we can maintain the fishery resources in a sustainable utilization.

Effects of different levels of sodium citrate, EDTA - Na2, HEPES, and sodium oxalate on anticoag-ulation of coelomocytes were studied in sea cumcumber Stichopus japonicus. The results showed that the coelomocytes were morphologically kept activity at 1.0 - 1.5 mg/mL EDTA - Na2, 3.8 mg/mL sodium citrate, 0.2 - 0.6 mg/mL HEPES, and 1.0 - 1.5 mg/mL sodium oxalate, EDTA - Na2 being the best anticoagulant.

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.

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.

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 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 solve the problem of low accuracy of fish detection caused by underwater imaging blur and distortion in actual aquaculture environment, a fish detection method(SK-YOLOv5)combining visual attention mechanism SKNet(selective kernel networks)and YOLOv5(you only look once)is proposed.In this method, UNet(convolutional networks for biomedical image segmentation)is firstly used to preprocess images to obtain clear fish images, and then SKNet is fused to Backbone end of YOLOv5 to form feature extraction network focusing on pixel-level information to strengthen the recognition ability of fuzzy fish.In this study, ablation test and model comparison test were carried out on underwater fuzzy fish swarming image data se to verify the effectiveness of SK-YOLOv5.The results showed that SK-YOLOv5 was effective in fish swarm detection task, and had recognition accuracy of 98.86% and recall rate of 96.64%, 2.14% higher and 2.29% higher compared with YOLOv5, respectively.Compared with XFishHmMp and FERNet with the maximal detection accuracy underwater target detection model, SK-YOLOv5 had the best detection effect, 5.39% higher in recognition accuracy, and 5.66% higher recall rate, and compared with FERNet, the recognition accuracy was improved by 3.59% and recall rate by 3.77%.The findings indicated that the fish detection of fusing SKNet and YOLOv5 can effectively enhence the identification ability of fuzzy fish, and improve the overall effect of fish detection and recognition.

In this paper we reviewed the physical and chemical nature, detection methods for tetrodotoxin and its derivatives, distribution among the species of organisms,and abilities of microorganisms which produce tetrodotoxin and its derivatives. The objective of present paper is to provide more necessary information about mechanism of toxic organisms accumulate toxins.

Mechanisms of sex determination in fish are complex and changeable procedures,and usually depend on interactions between genetic and environmental factors.Great progress in identification and characterization of fish sex determination and differentiation related genes has been made with the development of molecular biotechnology. It has been shown that sex determination and differentiation are influenced by environmental factors including temperature,photoperiod,pH,hypoxia,and water pressure in most fishes.Types of sex determination and differentiation,genetic sex-determination(GSD)and temperature-dependent sex determination(TSD),are proposed.Sex determination and differentiation is largely affected by temperature.The current advances on molecular players are reviewed,including Sox9,Dmrt 1,Amh,Foxl2,and aromatase genes,which are involved in sex determination and differentiation in fish temperature-dependent sex determination and differentiation,including temperature-dependent sex determination and genetic sex-determination plus temperature effects are emphasized.The influence of temperature on sex ratio of fish is discussed to provide valuable insights for elucidation of mechanisms of sex determination and differentiation in fish and for design of better fish breeding and reproduction programs in farmed fish.

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.

Based on a number of compaction tests, the compaction behaviour of heterogeneous soil is investigated in this paper. Then an empirical formula for assessing the maximum dry density of heterogeneous soil is proposed. It is shown that the proposed formula is practically applicable.

Types and levels of nutrients in feed not only affect gonad development, fecundity, gamete production, fertilization rate, hatching rate and embryonic development of aquatic animals, but also affect the quality and survival rate of their larvae. In the course of breeding, the common methods to promote reproduction mainly include physical heating and cooling, water stimulation, dry stimulation, and removal of eyestalks. In recent years, it has become the focus on scientific research and commerce to control the reproductive capacity of aquatic organisms by changing the types and levels of nutrients in feedstuffs. In this paper, the application status of common nutrients in aquaculture is reviewed, and the effects of different nutrients on the reproductive performance of aquatic animals are introduced. Many studies have shown that nutrients such as protein, fat, vitamins, minerals and sugars can significantly improve the growth performance and reproductive capacity of aquatic animals, but some contradictory results have also been reported. These results seem to depend on differences in the type, source, content, and experimental conditions of cultured aquatic animals. The purpose of this review is to discuss the effects of different sources and levels of nutrients on the reproductive capacity of aquatic animals and their mechanisms, so as to provide scientific basis for the promotion of aquaculture.

The histological structures of the sluge worm Perinereis aibuhitensis was systemically observed by light microscopy.Results showed that the worm consists of body wall,parapodium,digestive and emunctory systems.The body walls comprise of parietal peritoneum of a simple squamous epithelium,smooth muscular layers including circular muscle,longitudinal muscle and diagonal muscle,epidermis of single-layered columnar cells containing gland cells and sense cells and horniness layers.The cuticle layer is a non-chitin albuminoid velum secreted from the epidermal cells.The epidermis of parapodium,consistent with body wall,contain capillary vessels,connective tissue,mucilage cells and blood corpuscles.During the period of gonad development,a large number of germ cells are found in the parapldium walls.The digestive system includes the digestive tract,which is a straight tube from the mouth to the anal,buccal cavity,pharynx,esophagus,stomach and intestines.and the digestive gland on both sides of the esophagus.The excretory system is made up of nephridium.

Cellular and humoral immunity of crustacean are reviewed based on the data that have been issued in domestic and overseas journals. Hemocyte is the major immune factor and the reaction depends mainly on the hemocyte phagocytosis and encapsulation, but it is uncertain that the differentiation of the hemocytes and the roles are played by the hemocytes. The humoral immunity of crustacean is unspecialized. Some enzymes and regulatory factors in hemolymph, such as prophenoloxidase activating system, hemolysin, agglutinins,lysozyme and protease inhibitor are involved in humoral immunity of crustacean.

A series of changes of fish physical,chemical,biochemical and microbial properties during cold storage leads to the change in fish quality.The common indicators to evaluate the quality and determine commodity value of fish muscle are texture(hardness and springness),color,flavor and juiciness.In this paper,the reasons for changes of fish quality during cold storage,and factors to affect those changes are summarized.Aim to providing references for the study of different varieties and different quality of fish,the problems in storage methods and the future development of fish storage are discussed.

S-triazine herbicide prometryn is commonly applied to eradicate gramineae grasses and broad-leaf weeds in agriculture and illegally as an environmental improver to remove harmful algae and aquatic weeds in aquaculture industry. It as a suspected endocrine disruptor is stable in environment, difficult to be degraded and harmful to human through food chain. This paper reviews the degradation and metabolic pathways of prometryn, the structure and distribution of metabolic degradation products in environment, animals and plants, and the effects of prometryn on endocrine and immune functions, and the evaluation methods for human health and ecological environment safety. The extensive uses of prometryn result in a variety of metabolic degradation products with varied structures. The potential toxicity caused by long-term exposure to prometryn and various metabolites and the decline of ecological community population in environment will be the focus of our attention in the future.

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.

Acute toxicity of several disinfectants and antibiotics to juvenile sea cucumber Apostichopus japonicus was determined. It was found that the acute toxicity of the medicines to sea cucumber juveniles in a descent order ranged as oxytetracycline > norfloxacin > sulfamethoxazole. Medium lethal concentration (LC 50) in 24, 48 h of oxytetracycline is 166 mg/L, and 115 mg/L with safe concentration(SC) of 16.56 mg/L , respectively; LC 50 in 24,48 h of norfloxacin is 457, 407 mg/L, respectively, and safe concentration(SC)is 96.9 mg/L; LC 50 in 48, 72 h of sulfamethoxazole is 300, 224 mg/L, respectively. The toxicity sequence of the disinfectants to sea cucumber juveniles in a descent order ranged as chlorine dioxide > potassium permanganate > formalin > sodium chlorite > dipterex. The 24 h LC 50 of chlorine dioxide is 0.36 mg/L; the 24,48 h, and 72 h LC 50 of potassium permanganate is 3.02,2.09,1.26 mg/L, respectively, with SC of 0.23 mg/L; the 24, 48 h,and 72 h LC 50 of formalin is 8.71×10 -6,4.37×10 -6, 1.62×10 -6, respectively, with SC of 0.33×10 -6; the 24, 48, 72 h ,and 96 h LC 50 of sodium chlorite is 44.7×10 -6,14.5×10 -6,10.0×10 -6, and 9.3×10 -6, respectively, with a SC of 8.46 mg/L; the 24,48,72 h,and 96 h LC 50 of dipterex is 479,158,105,78 mg/L, respectively, with a SC of 6.49 mg/L. The feasibility of several common disinfectants and antibiotics in the culture of the sea cucumber was discussed.

The theory of the optimal stocking time of fish fry is developed from regular pattern of water quality and plankton development, especially rotifera peak period, after disinfection of a pond, and organ development of fry related to initial feeding, and includes two aspects: physiological optimal stocking time and ecological optimal stocking time. The physiological optimal stocking time indicates fry organ development gradually adapts to start feeding in terms of structure and function, and the ecological optimal stocking time indicates to provide the pond with initial feeding, suitable density and good external ecological environment conditions in the ponds. We review the development process of the theory of the optimal stocking time of fish fry and divided suitable initial weaning diets into nine types: rotifer, Artemia nauplii, Cladocera, Limnodrilus，bait fish fry, phytoplankton，body surface mucus, compound initial feed, and microparticle feed according to the research status of suitable initial feeding for main economically important fishes. “Timely” in this theory needs to be more accurate under different conditions. It is necessary to make a systematic study on the series of diets from initial feeding “mouth opening” (postlarvae) to juvenile stage in order to improve the survival rate of fry and ecological breeding.

The research status and prospectives of organisms in Chinese saline lakes were elaborated in this paper.The exploitation and utilizations of saline lake resource organisms have broadly prospects.The Salinology,one of a new course,should have being made a good progress.

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.

Modern marine ranching is a new exploitation mode of marine living resources that is suitable for modern sustainable development strategy, and plays an important role in promoting the structural reform of fishery supply, rapid development of ocean economy and the steady implementation of the strategy of building a strong maritime country in China.This paper summarizes the concept development, technology system and development status of modern marine ranching in China by systematically colleting relevant literature and combining with the latest research progress on marine ranching.The outstanding problems in the construction of modern marine ranching is discussed and development trend of modern marine ranching in China is presented.The development strategy can be made good progress from three aspects: modern science and technology, marine coordination and industrial integration to provide a reference for the scientific, normative and healthy development of modern marine ranching.

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.

Swim bladders as an important by-product during fish producing have rich sources. Extracts from fish air bladders with the acid, enzyme, hot water, salt, alkali and microorganism, collagen has a variety of biological properties such as low immunogenicity, high histocompatibility, strong cell activation, and good degradability, showing great medical values in cell culturing, wound healing, drugs manufacturing, and biomass power generating. The present paper describes the preparation process and structural characteristics of collagen from swim bladders of fish species and expounded their biomedical applications. Also, the current problems in research of extraction from different fish air bladders are discussed and the future development is looked forward to, aiming to fill the gaps in the medical field with the swim bladders so that realizing greater social value.

A total of 360 individuals of blunt snout bream Megalobrama amblycephala with body weight of(13.5± 0.5)g was randomly stocked into a tank with a stocking density of 30 fish and fed diets containing fructo-oligosaccharide(FOS)at a dose of 0,0.4%and 0.8%with four replication for 8 weeks and then activities of immune enzymes and antioxidant capability were detected in serum of 24 fish per tank exposed to 34℃by a colorimetry and an enzyme linked immunosorbent assay in order to explore effects of FOS on immune response and antioxidant capability of blunt snout bream under heat stress.The results showed that there were no significant differences in activities of glutamic oxalo acetic transaminase(GOT)and alkline phosphatase(AKP)among all groups in the fish without thermal stress(P＞0.05).Meanwhile,there were significantly lower activities of glutamic pyruvic transaminase(GPT)in the fish fed the diets containing FOS than that in the control group(P＜0.05).The blunt snout bream fed the diet containing 0.4%of FOS group had significantly lower GPT activity(P＜0.05)than the animals fed the diet containing 0.8%of FOS,without significant difference between in 0.8%FOS group and the control group in 24 h(P＞0.05).The fish fed the diet containing 0.4%of FOS exposed to 34℃for 12 h showed significantly higher AKP activity than the fish in the other groups did(P＜0.05).There were significantly higher complement 3(C3)and complement 4(C4)in 0.4%FOS than that in the control without thermal stress(P＜0.05)and with 3 h and 6 h thermal stress,without significant difference between the control and the 0.8%FOS group(P＞0.05).There were increase in activities of superoxide dismutase(SOD)and total antioxidant enzyme(T-AOC) among all groups with thermal stress,without significant difference(P＞0.05).The activities of catalase(CAT) and T-AOC were shown to be significantly higher first in fish fed the diet containing 0.4%of FOS than those in the control group(P＜0.05),the maximum in 6 h thermal exposure,significantly higher T-AOC activity in 0.4%FOS group compared to that in the control group at 3 h and 6 h thermal exposure(P＜0.05).The malondialdehyde (MDA)contents were increased first and then decreased with thermal stress,significantly lower in 0.4%FOS group than that of the control group in 0 h and 48 h thermal exposure(P＜0.05).In addition,there was no significant interaction between the FOS levels and the sampling time(P＞0.05).In conclusion,dietary supplementation of 0.4%FOS may effectively relieve the adverse effects of heat stress on blunt snout bream.

The species，functional mechanism and application of antagonistic bacteria in animal pathogens in aquature are reviewed to research for preventive and controll measures to replace antibiotics in aquaculture.Moreover，the new trends and prospects of probiotics application in aquaculture are also discussed.The findings will provide references with research and development of probiotics and control of the disease in aquaculture.