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 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.

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.

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.

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.

Embryonic development of haploid, triploid, gynogenetic diploid and normal diploid Japanese flounder （ Paralichthys olivaceus） were observed at a water temperature of （ 16 ± 0. 5 ） ℃, pH value of 8.0 - 8.3, and a salinity of 30.2. A high frequency of abnormality, particularly body flexion, the organ differentiation, the fertilizing rate, the rate of abnormality and the hatching rate was found in the haploid embryos. The embryos of gynogenetic diploid and triploid had basically the same process with the normal diploid embryos, as the zygotes developed through multicelled stage, blastula stage, gastrula stage, neurula stage, yolk plug formation stage, Kupffer＇s vesicle stage, tailbud stage, eye len formation stage, heart beating stage, hatching stage and hatched successfully. There were no significant differences in embryonic development among gynogenetic diploid, triploid and normal haploid individuals. However, different time of every stage was found in embryonic development among gynogenetic diploid, triploid and haploid individuals. It took about 61 hours to hatch for the control diploid. For gynogenetic diploid and triploid, however, it took 66 hours 30 minutes and 67 hours 50 minutes to hatch, respectively, about 10% longer than the developmental time of the control diploid. Noticeably, the gynogenetic diploid and triploid had about 25% longer than the control diploid at the multicelled stage. The hatching rate of （16. 5 ±2. 2）% and abnor- mity of （97.2 ± 1.6） % happened to the haploid. The hatching rate of （85.6 ± 3.0） % and （ 82. 3 ± 3.1 ） % occurred in both gynogenetic diploid and triploid with the abnormality of （13.2± 2. 3 ）% and （16. 3 ± 2. 5 ）% respectively, no significant differences between gynogenetic diploid and triploid. But compared with the control diploid, both gynogenetic diploid and triploid had a lower hatching rate and higher abnormality.

The improved potassium periodate oxidation spectrophotometry was used to determine the manganese content in sea water and the reagent amount, chromogenic curves, absorption curve, the coefficient of variation and some influencing factors were evaluated. This method was found suitable for determination of manganese with the optimal range of 1 to 50 mg/L in sea water and 1 to 30 mg/L in fresh water, with variation coefficient of 0.31% - 26.61% and recovery efficiency of 76% - 112%.

In response to increasing strict regulations on aquatic product quality, organic matter and nitrogen discharge, industrial recirculating aquaculture systems (RASs) are getting more and more application because of their minimal environmental impact and controlled operation. As a core unit of RASs, marine biofilters play an important role in controlling water quality. It is important to establish a scientific, reasonable and efficient design to improve the purifying efficiency of the biofilters. In this paper, the production situation of a certain farm was taken as an object to design a moving bed biofilm reactor using material balance principle and water purification facilities construction technology. Under the guidance of the balance principle of nitrogen, the maximum ammonia production rate, maximum allowable ammonia nitrogen concentration in culture ponds, quantity of exchanged water, and oxygen demand of the tank and biofilter were calculated based on the oxygen consumption rate of aquaculture organisms, oxygen consumption of nitrification and the dissolved oxygen balance. The three flow rates required for removal of target ammonia nitrogen and for dissolve oxygen in the culture tank and biofilter were calculated. On the basis of the above calculation, several key parameters were precisely established according to the water treatment facilities construction technical specifications and production experience, including the flow rate, volume, circulation, hydraulic retention time, quantity of exchanged water and filtration equipment. The main technical parameters were determined as the circulated flow rate of 286 m3/h, volume of 140.59 m3in four biofilters of each 4 m×4 m×2.5 m, the water level of 2.2 m, hydraulic retention time of 29 min, exchanged water of 1.16 m3/h, at a rate of 20 times a day, the diameters of 300 and 200 mm in total and branch inlet pipe, blower volume of 1716 m3/h and the carrier Kaldnes K3 filling with 40%. It is put forward to provide a complete design method for the proper design of biofilter with the above process. The findings provide a good reference for the design of moving bed biofilter reactor in recirculating aquaculture system.

The population structure, reproduction characteristics and the regular migration pattern were investigated in large yellow croaker Pseudosciaena crocea by a survey and collected data of the fishery resources in Zhejiang coast and the East China sea in recent years. The results showed that overfishing due to great capture capacity and intension led to the stock decline since 1970＇s. Since mid - 1980＇s there was no fishing season of the large yellow croaker in the main fishing ground because of the excess capture, although fishery department had carried out many measures to protect the stock. The large yellow croaker still are listed in the species whose stock was declined seriously in the East China sea. The population structure of the fish population presents lower age, early maturation and miniaturization in size, the predominance population with 1 age and 140 - 160 mm in body length after 1990＇s compared with 4 -7 age and 220 -350 mm in the 1970＇s.

Toxicity of 13 kinds of Chinese herbal medicines including  Cortex   dictamni ,  Sophorae   flavescentis ,  Herba   andrographis ,  Fructus   toosendan ,  Fructus   quisqualis ,  Pseudolarix   amabilis ,  Agrimonia   pilosa ,  Carpesium   abrotanoides ,  Areca   catechu ,  Gleditsia   sinensis ,  Radix   stemonae ,  Fructus   cnidii  and  Rhizoma   arisaematis  at a dose of 900 mg/L to ciliate  Diophrys   appendiculata  were screened by static bioassay test at normal light-dark (14L∶10D) and complete darkness. It was found that  Areca   catechu ，  Agrimonia   pilosa  and  Pseudolarix   amabilis  had better efficacy for killing the ciliate among the 13 kinds of Chinese herbal medicines at concentration of 900 mg/L. Then acute toxicity of  Areca   catechu (at a dose of 0, 30, 40, 50, 60, 70, and 80 mg/L),  Pseudolarix   amabilis (at a dose of 0, 190, 210, 230, 250, 270, and 290 mg/L), and  Agrimonia   pilosa  (at a dose of 0, 310, 340, 370, 400, 430, and 460 mg/L) to the ciliate was determined in order to prevent and control pathogenetic ciliate in aquaculture. The results showed that 100% of the ciliate was found to be dead at  Areca   catechu  concentration of 80 mg/L for 48 h at normal light-dark, and 97.8% of the ciliate dead for the 96 h at complete darkness. 100% mortality was observed in the ciliate exposed to  Agrimonia   pilosa  concentration of 460 mg/L， for 72 h at normal light-dark, and 77.8% mortality was observed in the ciliate exposed to  Agrimonia   pilosa  concentration of 460 mg/L for 96 h at complete darkness. The ciliate exposed to  Pseudolarix   amabilis  concentration of 290 mg/L for 96 h had 90.0% of mortality at normal light-dark and 84.4% of mortality at complete darkness. The 24 h LC 50  to the ciliate was shown to be 65.964 mg/L in  Areca   catechu ， 261.194 mg/L in  Pseudolarix   amabilis  and 419.169 mg/L in  Agrimonia   pilosa  at normal light-dark, showing the descending acute toxicity order of the Chinese herbal medicines as  Areca   catechu  >  Pseudolarix   amabilis  > Agrimonia   pilosa . The findings indicate that  Areca   catechu ,  Agrimonia   pilosa  and  Pseudolarix   amabilis  can treat the harmful ciliates in aquaculture，  Areca   catechu  being used as the first medicinal plant at the optimal concentration of the 80 mg/L to control ciliate  D . appendiculata .

Aquatic germplasm resources are an important material basis for fishery development. There are more than 500 species of echinoderms in China, among which sea cucumbers and sea urchins are important aquaculture species. Since the construction project of aquatic primary and improved species started in the 1990s, economic echinoderm germplasm resource protection has made great progress in China, and an economic echinoderm seed industry system with Chinese characteristics has been initially established. However, there are still many problems and challenges at different aspects. In this article, we summarized the distribution, identification, evaluation, protection and innovation of germplasm resources of economic echinoderms (sea cucumbers, sea urchins), and put forward suggestions on the construction of economic echinoderms national aquatic product original breeding farms, germplasm resource testing and evaluation system, germplasm resource bank and information sharing platform, as well as sea cucumber and sea urchin “integration of breeding, reproduction and promotion”. These efforts are valuable to promote the protection of echinoderm germplasm resources in China, and the physical efficiency and green development of the seed production and aquaculture industries.

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.

Cultivating excellent disease-resistant fish varieties can effectively solve and reduce more and more serious disease problems with the transformation of aquaculture mode from extensive to intensive. The development of fish disease-resistant breeding is primarily summarized, including the research progress of family and population breeding, molecular marker-assisted breeding, genomic selection and major histocompatibilty complex (MHC) gene polymorphism and disease resistance. Family and population breeding, one of the important means of selective breeding, has been widely used in a variety of fish disease-resistant breeding research. The introduction of molecular marker-assisted breeding and genomic selection has also promoted the progress of disease-resistant breeding in the aquaculture industry. In addition, the high polymorphism of the fish  MHC  gene associated with disease-resistant phenotype has made it a candidate for disease-resistant breeding molecule markers. The problems and shortcomings in the breeding of disease-resistant fish and the prospect of disease-resistant breeding of fish are discussed in the future, aiming to provide reference with the green and healthy development of the aquaculture industry.

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.

The complement hemolytic activity was reported in the coelomic fluid of sea cucumber Apostichopus japonicus, a rate of （68.8 ± 13.5） U/mL. The ACHso assay revealed that the optimum conditions for the complement hemolytic activity in the coelomic fluid were as the following- pH 7.5,8 mmol/L Mg^2＋ EGTA - Mg - GVB buffer, at 20 ℃ and reaction period of 90 min. The haemolytic activity was affected by Mg^2＋ and inhibited by zymosan, methylamine, hydrazine and PMSF.

The age and growth of squid Sthenoteuthis oualaniensis were studied using 104 statoliths collected in the Chinese squid jigging surveys from October 2004 to January 2005. It was found that the squid had a life span of about one year, the samples being 88 to 363 day old, 81.3% ranging from 180 to 270 day old. The incubation samples were found almost throughout the year from January to November in 2004, with two peaks of March to May and September to October, accounting for 57.8% and 14.4% of the total, respectively. Two distinct spawning groups were observed in spring and autumn. The relationship between mantle length and age was described by the linear function and the relationship between body weight and age the exponent functions in the two spawning groups. The instantaneous relative growth rate and absolute growth rate were found to be varied with the sizes, with significant difference between the groups of squid with the same age.

Approximate compositions, minerals, fatty acids, amino acids, nucleotides, and cholesterol were analyzed in muscle and testis of male Chinese mitten handed crab  Eriocheir   sinensis  from different waters including Gucheng Lake of the Yangtze River, Yangcheng Lake, Liaohe River(estuary) and the Yellow River(middle and upper reaches) by biochemical analysis to evaluate nutrition quality of male Chinese mitten handed crab from different waters. It was found that there were significant differences in the composition of trace elements, amino acids and cholesterol in Chinese mitten handed crab from Gucheng Lake, Yangcheng Lake, Liaohe River(estuary) and the Yellow River(middle and upper reaches). There was significantly higher content (284.3 mg/kg)of iron in the testis in male crabs from Liaohe waters than that in the crab from the other waters( P <0.05), with significantly higher content(63.5 mg/kg) of zinc in the edible part of male crab from Gucheng Lake than that in the crabs from the other waters( P <0.05). The male crab from Gucheng Lake had significantly higher polyunsaturated fatty acid content in edible parts than that the crabs from the other waters did( P <0.05), with significantly higher amino acid contents (taste amino acids, essential amino acids and total amino acids) in the crabs from Gucheng Lake and Yangcheng Lake than those in the crabs from Liaohe and Yellow River( P <0.05). In addition, the contents of inosinic acid in testis of the crab from Liaohe River were more abundant, indicating that the nutrient compositions in the edible parts were varied with the sources of Chinese mitten handed crab. The findings provide support with data for the quality standards and identification indicators of Chinese mitten handed crab.

The occurrence, process and histological characteristics of gonadal differentiation were histologically observed in Japanese flounder Paralichthys olivaceus. One elliptical primordinal germ cell （PGC） was observed by the 10th day posthatching（dph） （4.2 mm in total length）. On the 20th dph （6.6 mm TL）, the gonad anlage emerged, and remained undifferentiated by 30th dph （9.7 mm TL）. The anlage of the efferent duct was found on the 50th dph （23.8 mm TL）. On the 65th dph （47.5 mm TL）, the dorsal and ventral edges of the gonads began to extend laterally and eventually fused to form the presumptive ovarian cavities along the lateral sides of the gonads. The spermatogonia were first recognized in the testis on the 85th dph （84.3 mm TL） and oocytes in early meiosis were first observed from the 105th dph ovary （124.5 mm TL）, indicating that the sex differentiation is evident distinctness between female and male. The differentiation occurred earlier in male than in female.

Planktonic community features in a hatchery water system for short - necked clam, Ruditapes philippina rum were investigated at Haiyang village of Zhuanghe, Dalian, Liaoning Province in China from May to November in 2005. Totally, sixty - two taxa （most diatom）of phytoplankton （the biomass of 2.90 -30. 91 mg/L） were found in the water, with the predominant species of Nitzschia closterium, Chaetoceros lorenzianas, Nitzschia sp. , Phaeodactylum tricornutum, Navicula sp. , Chroomonas acuta, Chlorella vulgaris, and Euglena viridis, and the maximum mean biomass （16.78 mg/L） at the exit of a deposit pond, followed by in the entrance station, and the minimum at the exit of the purifier pools. There were forty - five taxa of zooplankton comprised of eopepods and its nauplius or copepodite, Leprotinnus nordquisti, Chilodonella vorax, Strobilidium gyrans, Brachionus plicatilis, Epiphanes senta, Paracalanus parvus, Corycaeus affinis and Cypris subglobosa being the predominant species. The mean density of the zooplankton varied from 5.5 ind./L to 118 ind./L, with mean biomass of 0.01 mg/L to 5.97 mg/L, the maximum biomass （2.48 mg/L） in the shallow area, and the minimum in the purifier pool.

In this paper, the advances in the research on effects of environmental factors including thermal environments, hydric environments and medium on the incubating eggs, embryo development and hatchlings of turtles are summarized to provide more necessary information on mechanism of the affections of environmental factors influencing embryo development of turtles.

Erythromycin thiocyanate was added into 15 cylindrical bottom sediment enclosures made of high density impermeable canvas and stainless steel iron frame in an circulating water channel with frequent cyanobacterial bloom outbreak at a dose of 0(control group), 0.25, 0.5, 1 mg/L and 2 mg/L for 10 days to clarify the dynamic changes in cyanobacteria and  Microcysis  abundance, microcystin(MCs)content in sediment and key hydrochemical indicators under the action of algaecide agent.The erythromycin thiocyanate was shown to have very strong inhibitory effect in cyanobacteria and  Microcysis  in the ecological enclosure, with inhibitory rate of 99% at the end of experiment.There was increase in content of microcystin in sedimentt first and then decrease under the action of erythromycin thiocyanate, with the maximum MC-RR content of 2.58 μg/g and MC-LR of 3.39 μg/g at the second 2 d.The increase in contents of   and COD Mn  was observed to some extent in a short time after emergency controlling of cyanobacteria bloom by erythromycin thiocyanate, especially the content of   and COD Mn .Considering the algaecide effect, MCs storage in sediment and the change rule of key hydrochemical indices, it is recommend that erythromycin thiocyanate be applied at a dose of 0.25 mg/L to control cyanobacteria bloom in emergency, accompanied by operating aerators, and administration of probiotics in aquaculture.

The running - in wear test for materials of crankshaft journal against bearing shell of S50MC marine diesel engine has been conducted by a ring - on - disc tester in this paper. The effect of performance of running - in wear for AlSn40 alloy bearing shell under different axial loads has been studied by the complicated analysis of friction coefficient, wear loss, and surface roughness. There were the certain differences in running - in wear prop- erties of AlSn40 alloy bearing shell under different axial loads. When the test load was less than 40 N or more than 60 N, its running in wear properties were poor. When the test load in 40 -60 N, its running in wear properties were best. Therefore, AlSn40 alloy bearing shell will obtain a good running - in wear properties in the middle axial load.

Ascidians as a typical marine fouling organisms can rapidly attach to the surface of underwater substrate temporarily by means of papillae during larvae, and subsequently developed successively to reach permanent adhesion via ampulla, adhesive projection and stolon. The special adhesive organs and associated complex mechanisms make it difficult to develop antifouling strategies against these species. However, it also brings new ideas for the development of novel hydrogels or effective antifouling surfaces. Here, we review the mechanisms of biological adhesion at larval and adult stages in ascidians, and summarize the existing research on antifouling and biomimetics. The research progresses are suggested including adhesive organs, identification and analysis of adhesive proteins, designing specific materials for preventing adhesion of ascidians, and biomimetic research of ascidians based on the molecular level to provide theoretical reference for further studies on the adhesion mechanism of marine organisms and the development of antifouling strategies and bionic materials.

The embryonic development and initial feeding of larvae were observed in large icefish Protosalartx hyalocranius under a Pixera Penguin 600CL digital camera system.The fertilized eggs were hatched in 852 hours at water temperature of 4-9℃and the embryonic development was divided into 9 physiological stages,namely 30 developmental substages.The newly hatched larvae had average body length of 4.76 mm and total body length of 4.86 mm.The yolk sac was exhausted about 20 days after hatching,and the fry with body length of 5.85 mm and total body length of 6.09 mm was found to swim normally.The larvae fed on phytoplankton as weaning food in the 10-20 initial feeding days under unfed condition,and began to feed rotifers actively 20-40 days after initial feeding. Microscopic observation revealed that the shells and resting eggs of the rotifers were not digested by the larvae.

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.

A protoplast fusion was conducted between two efficient photosynthetic bacteria,N-ammonia degrading Candida sp.and N-nitrite degrading Rhodospeudomonas capsulate.The conditions of the protoplast formation and fusion were optimized,and the best fusant was selected.The better protoplast formation for Rhodospeudomonas capsulata was found under the conditions of:lysozyme at 1.5 mg/mL,EDTA 0.1 g/L and 45 min reaction time;for Candida sp.the better conditions of snail enzyme at 0.5 mg/mL,mercaptoethanol 0.1%,EDTA 1 g/L and 30 min reaction time.The fusion was induced by PEG 6000 and Ca 2+ .Fusants were screened out by selective media containing added nystatin and streptomycin.The fusant R1 with better efficient degradation was selected by growth stability and degradation.The fusant R1 showed N-nitrite degradation at a rate of more than 90%,as good as for Rhodospeudomonas capsulata,but had N-ammonia degradation of only 63%,increased by 54%.

The juvenile Siberian charr Salvelinus leucomaenis was cultured at 4 different stocking densities of 3.33, 6.93, 10.01 kg/m3 and 13.65 kg/m3 for 48 days to evaluate the influences of stocking density on growth, survival and behavior. The results showed that there were no significant effects on survival and condition factor, but significant effect on the variation in growth （P =0.001 ）. There was a positive correlation between the body weight coefficient variation and the stocking density（ CV = 0. 288SD -5.999, R =0. 875, P =0.004）. The specific growth rate was diminished with the increase in stocking density, with significant negative correlation （SGR = 15. 220 -5. 908 SD, R = - 0. 832, P = 0. 005） and the net gain was increased with the increase in stocking density （P = 0.000）. The behavior was, to some extent, affected by stocking density. The fishes feeding at the bottom at lower density had lower aggregation, and more uneaten food and were sensitive to the environmental stimulus including light, and sound. There was more frequency in aggregation in higher density than that in lower density, leading to irritable.

Light as the most important environmental factor affecting growth of aquatic animals has formed a unique sensory system and light regulation of physiological mechanism in aquatic organisms via one hundred million years of evolutionary adaptation. At the present, lighting technology development obviously lags behind the demand for the development of aquaculture, as well as the industry transformation technology requirements. This paper summarizes the research and application status of LED technology in aquaculture, aquatic disinfection and sterilization, microalgae culture and pelagic fisheries, and the development prospect in the future is put forward through comparative analysis, being combined with the green development and high efficiency and high quality demand of aquaculture and fisheries in China.

The fault tree analysis（FTA） method in system safety analysis is applied to analyze the marine accidents.As an example,the fault tree is built up according to the influence of various factors of ship collision accident and their logical relationship,and analyzed qualitatively to find out important degree coefficient of each factor and minimal path-sets.Then control measures of accidents are put forward to avoid the ship collision accidents.The results show that this method can reflect the fact systemically and objectively,find out the direct reasons for the accidents,summarize the experiences and lessons,and put forward the precautionary measures.It may play an important role in the control of marine traffic accidents.

Strain IP0004 as a pathogenic strain was isolated from the liver of diseased channel catfish （lctalurus punctatus）. The isolated strain was proved to be classified as Plesiomonas shigelloides by morphological, physiological and biochemical analysis, and sequencing of 16S rRNA. The bacterium was Gram positive, secreted acid production from glucose, maltose and trehalose and had monotrichate flagellum without spores. ONPG test showed that the strain had positive ornithine decarboxylase, lysine decarboxylase, arginine dihydrolase, β - galaetosidase, and α- galactosidase, and negative urease, lipase, β- glucosidase, N - Acetyl -β- Glucosaminidase, β- Glucuronidase, and L - Aspartic acid Arylamidase. The optimum isolation was observed at a salinity of 0 - 25, pH 5 - 10, temperature of 37℃. The similarities of the 16s rRNA gene sequences in the strain IP0004 to other Plesiomonas shigeUoides were more than 99%. Phylogenetic tree based on these sequences showed that the strain IP0004 clustered together with Plesiomonas shigelloicles. The similarities of COMP（ cytotoxic outer -membrane protein） gene of the isolation to other COMP genes of Plesiomonas shigeUoides are more than 99.9%, so strain IP0004 has COMP gene. The test of sensitivities of strain IP0004 to 15 kinds of antibiotics revealed that IP0004 was sensitive to drugs such as ceftriaxone, cefradine, cefamezin, and ofloxacin, but not to novobiocin, rifampicine, and sulfamethoxazolum.

Mollusc aquaculture plays a dominant role in the aquaculture industry of China. However, the frequent outbreak of summer mortality has heavily threatened the development of the mollusc aquaculture industry. Since the mollusc species lack the acquired immune system and are usually cultured in the open water bodies, it is global puzzle to effectively control the occurrence and prevalence of diseases through water quality regulation, application of vaccine or other pharmaceutical preparations. It is urgent to develop an early warning system for diseases control to reduce the economic loss. In this article, we summarize the research progress of an early warning system in aquatic animals from the aspects of microbiology, immunology, physiology, pathology, ecology, and aquaculture. Furthermore, we discuss the methodology for the construction of early disease warning system and its application in marine mollusc aquaculture based on our primary research progress in the Yellow Sea and Bohai Sea. This review will provide the theoretical basis for the development of early warning system for the sustainable development of aquaculture.

Fish index of biotic integrity（F-IBI） was used to assess the environmental conditions in Taizi River basin.Five indexes including total number of taxa,total fish catch,percent of subfamily Leuciscinae,percent of tolerant species,and percent of widespread species were selected for the establishment of F-IBI by analysis of reflect disturbance,Pearson correlation and judgment ability performed on 23 candidate metrics in the samples collected from 61 sites（26 reference sites and 35 impaired sites） in Taizi River basin during May of 2009.The values of metrics were calculated by three scoring methods,and F-IBI was established by combination of the 5 indices.The values of IBI were found to be ranged from 5 to 25,IBI=25-22 for the healthy fish,21-18 for the sub-healthy,17-14 for the fair,13-10 for the poor,and 9-5 for the very poor.The results showed that there were 19 sites for the healthy,11 sites for the sub-healthy,12 sites for the fair,11 sites for the poor and 8 sites for the very poor in Taizi River basin,and there were significant relationship between the IBI values and habitat quality（P0.01）.

Karyotypes and morphological characteristics were analyzed and compared in wild diploid, triploid and tetraploid individuals of oriental weatherfish Misgurnus anguillicaudatus collected in Honghu lake, Hubei province, China. 1 ） The chromosome number, karyotype and fundamental number were determined to be 2n =50, 10m ＋4sm ＋36t, NF =64 in diploid, 3n =75, 15m ＋6sin ＋54t, NF =96 in the triploid, and 4n = 100, 20m ＋8sm ＋72t, NF = 128 in the tetraploid. 2） There were no significant differences in five structured meristic parameters between diploid and tetraploid oriental weatherfish, but significant differences in three parameters in the diploid and the tetraploid ones. 3） Principal component analysis revealed that such morphological differences were attributed to the different lengths of the posterior half of the body in specimens with different ploidy. （4） Cluster analysis showed that diploid and tetraploid Oriental weatherfish were morphologically similar, but the triploid remotely related to them.

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.

The growth and nitrification performances of plastic ring, volcano stone and oyster shell biofiher media were studied in a water recirculation system for Japanese flounder Paralichthys olivaceus culture by determination of the nitrogen concentrations of ammonia, nitrite and nitrate. Ammonia removal was compared in the same filter media 5, 15, 20, 30, and 60 min after hydraulic retention. The nitrification kinetics and ammonia removal rate were studied by ammonia concentrations decreasing with time at different initial ammonia - N concentrations of 1, 3, and 5 mg/L. The maturation time of the three types of filter media was found to be about 25 d. The maximal heerotrophic bacteria and the nitrite bacteria and the maximal active oxidation -reduction reaction were observed on the plastic ring among three types filter media, fowlled by on the volcano stone, then on the oyster shell. The optimum hydraulic retention period of the three types of filter media was found to be 20 - 30 rain. The biodegradation of ammonia - N followed the zero - order kinetics in 12 h at the nitrogen load of 1 mg/L, and in 24 h at the nitrogen load of 3 mg/L or 5 mg/L. The ammonia removal rate by the three types of nitrification filter was 17.51 - 16.39, 36.39 - 33.04,and 58.96 -53.25 g/（m3 · d） at nitrogen load of 1,3,5 mg/L.

The individual fecundity and the related physical characters were evaluated between northern pike Esox lucius and Amur pike Esox reichrti.The results showed that northern pike had absolute fecundity（F） between 3 808 and 173 500 eggs and Amur pike between 5 380 and 184 630 eggs.There was very significant difference in individual relative fecundity to weight（FW） between northern pike and Amur pike（P0.01）,while there was no significant difference in individual relative fecundity to length（FL） between northern pike and Amur pike（P0.05）.F,FW and FL were all found to show normal distribution,and the relationships among F,FW and FL and main physical characters were close in northern pike.In Amur pike,only the relationship between F and main physical characters was also close related in stead of the others.The multiple stepwise regression equations of F,FL and FWin northern pike,and the main physical character measures were F=-50090.38＋421.661Wo-74.083Wn＋205.845L,FL=6.977＋0.271 Wo and FW=-5.88＋0.37L＋0.514M,respectively.For Amur pike,the multiple stepwise regression equations of F,FL and FW and the main physical character measures were F=-19300.721＋33.262 Wn ＋728.415M,FL=-20.948＋0.129 Wn ＋2.056M-0.071W and FW=15.743＋0.661M.Both pike spawn only once a year according to the frequency distribution of ovum diameter.

Indoor artificial breeding of clam Dosinia laminata was carried out, and 3 millions of juveniles with shell length of 1.2 - 1.5 mm were produced from May to September in 2007. The fecundity was found to be 2 millions per female with shell length of （60.90 ± 2.24） mm, and the D - larvae were observed after about 22 hours and 40 minutes after fertilization at water temperature of 24.5 - 25.5℃, salinity 27 and pH 7.5. The eggs were （70.33 ± 1.06） μm in diameter, and the D - larvae, postlarvae, single - siphon and double - siphon juveniles had shell length x shell height of （ 100.33 ± 1.30） μm × （81.07 ± 1.72） μm, （213.33 ± 8.02） μm × （202 ± 5.96 ） μm, （309.17± 9.17 ） μm × （301.67 ± 10.81 ） μm, and （ 1158.33 ± 9.31 ） μm × （ 1067.50 ± 10.84 ） μm, respectively. The daily growth of （8.28 ± 0.70 ） μm × （9.19 ± 0.76 ） μm , and survival rate of （ 36.8 ± 3.78 ） % was kept during the pelagic stage. During the metamorphosis （4 - 5 days）, the daily growth was （ 8.46 ± 0.42 ） μm × （ 8.04 ±0.45） μm, with metamorphic rate of （5 ± 1.25）%. The later single -siphon, and double -siphon juveniles had good growth at average rate of （32.19±20.63） μm × （28.75 ± 19.71 ） μm, （53.07 ±40.43） μm × （47.86 ± 38.22） μm per day,and survival rate of （81.2 ± 3.36）%. Compared with other substrata, the sea mud as a substrate had better collection of juveniles.

The inductive effects of predatory rotifer Asplanchna brightwellii on morphological plasticity in four rotifer results showed that these four rotifer species cultured in the Asplanchna - conditioned medium had significant increase in the length of spines than in an ordinary culture medium, but there were no significant differences in the length and width of the body. The evolutionary and ecological significances of the morphological plasticity in four Brachionus species induced by the predators were discussed in the paper.

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.