Abstract:Somatostatin (SST), is a kind of neurohormone with key roles in regulating growth and metabolism in all vertebrates. In zebrafish and other fishes, SST peptides are encoded by six genes, and sst1 exists in all vertebrates and is the most evolutionarily conservative. Here, we explored sst functions through a transcriptomic comparison of 6 days post fertilization (dpf) zebrafish sst1^-/- mutants generated by CRISPR/Cas9 gene-editing technology and their wild type counterparts. It is found that several biological processes and biochemical pathways were modified in sst1^-/- zebrafish. The mutant had 354 significantly up-regulated and 504 significantly down-regulated genes. Gene ontologyi(GO) enrichment analysis showed that most of the differentially expressed genes were related to the biosynthesis of amino acids and proteins. Kyoto encyclopedia of genes and genomes(KEGG) pathway enrichment indicated metabolic pathways as well as pathways related to amino acid biosynthesis, aminoacyl-tRNA biosynthesis, ribosome biogenesis and rRNA processing were highly represented in the mutant, indicating a more active protein biosynthesis and metabolism. The results of RT-qPCR illustrated that the mRNA expression trends of 10 randomly selected genes were consistent with the results of transcriptome sequencing analysis, indicating that the transcriptome results were accurate and reliable. There was no significant difference in body weight and body length between 6-month-old mutant and wild-type. The results provide a foundation for further exploring the potential functions of the somatostatin gene family.

Abstract:In order to develop and set up ecological multistory culture pond ecosystem of obscure puffer (Takifugu obscurus), Litopeneaus vannamei, and Ipomoea aquatica Forsk, the differences of the water quality changes and the cultural efficiencies between multistory culture model and traditional monoculture model of obscure puffer were studied. The results showed that the values of water quality parameters of pH, TAN, NO₂-N, and NO₃-N in the pond of multistory culture model and traditional monoculture model of obscure puffer maintained within the ideal range. In these parameters, except that the NO₃-N(0.110 mg/L)of the multistory culture model on July 8 was significantly lower than the NO₃-N(0.630 mg/L)of the traditional monoculture model, there was no significant difference in other parameters between the two models. The Chl a of the multistory culture model was significantly lower than that of the traditional monoculture model. The scopes of the average total nitrogen (TN) in two models were 1.38-3.96 mg/L and 1.04-3.20 mg/L, respectively, in the middle and later periods of the culture (from July 24 to October 11), the TN of the multistory culture model was significantly higher than that of the traditional monoculture model. During the cultural time, the total phosphorus (TP) of the multistory culture model showed a trend of slow rising steadily (0.26-0.42 mg/L), while the total phosphorus (TP) of the traditional monoculture model showed a trend of high middle (0.50-0.56 mg/L) and low on both sides (0.18-0.37 mg/L). Except that the COD value of two models on May 6 is relatively high (the multistory culture model 14.05 mg/L and the traditional monoculture model 15.03 mg/L, respectively), in the other monitoring points in time, COD values are relatively stable, the mean ranges were 6.79-10.24 mg/L and 6.83-9.15 mg/L, respectively, and there was no significant difference between the two models. Overall, the TSS (total suspended solid) value was higher, especially source water on June 13(154.20 mg/L), the traditional monoculture model on 24 July and August 19(186.60 mg/L and 181.53 mg/L, respectively), and the multistory culture model on September 15(189.87 mg/L), these TSS values were more than 150 mg/L. In each monitoring point in time, there was no significant difference in the TSS between the two models. Obscure puffer culture was advantageous to the purification of pH, TAN, NO₂-N, and NO₃-N in pond water of the two models, and there was no obvious influence on the TP and TSS in pond water, while, it caused the increase of total nitrogen (TN) and COD in pond water. There was no significant difference in growth of obscure puffer between the multistory culture model and the traditional monoculture model, the stocking density (12 000-15 000 ind/hm²) of the two models did not cause space stress of obscure puffer growth. Except that the obscure puffer unit yield (3 426.0 kg/hm²) of the multistory culture model was significantly lower than that of the traditional monoculture model (4 055.7 kg/hm²), there was no significant difference in out-pond specification (293.30 g/ind and 297.53 g/ind, respectively), survival rate (97.38% and 94.60%, respectively), and food coefficient (2.83 and 2.91, respectively) between the two models. Litopeneaus vannamei of polyculture in the multistory culture model showed good growth performance:the unit yield of Litopeneaus vannamei was 3 056.6 kg/hm², the out-pond specification was 22.48 g/ind, the survival rate was 78.17%, and the food coefficient 0.68, and the overall superimposed feed coefficient of fish and shrimp was 1.39. Compared with the obscure puffer traditional single model, under the condition of 11.1% reduction in aquaculture tail water discharge, the benefit of the multistory culture model increased by 87 675 yuan per ha.

Abstract:In order to investigate whether there are any losses in nutrition or a decrease in flavor and quality of female E. sinensis after overwintering, female E. sinensis was reared for 105 days in 3 cages embedded in a pond recirculating aquaculture system. By comparing the general nutrition indices, proximate composition, fatty acids, free amino acids, nucleotides and volatile flavors of E. sinensis before and after overwintering cultivation, it is found that there was no weight loss in the total edible tissues and that E. sinensis was in stable growth during the overwintering cultivation. Interestingly, it is found that after 105 days of overwintering cultivation, the total content of free amino acids decreased(P<0.05), while the ratio of essential amino acids to free amino acids increased significantly(P<0.05), and the ratio of non-essential amino acids to free amino acids decreased significantly(P<0.05), the ratio of essential amino acids to non-essential amino acids increased significantly(P<0.05). After overwintering cultivation, moreover, adenosine (AMP) and inosinic acid increased significantly(P<0.05), while hypoxanthine and inosine decreased significantly(P<0.05), Although crude fat, C22:1 and C22:4 contents in edible tissues and ovaries were significantly decreased, polyunsaturated fatty acids, such as C20:2(eicosadienoic acid),C20:4(arachidonic acid)and C20:5(eicosapentaenoic acid), were significantly increased(P<0.05), Meanwhile, the PUFA/SFA ratio increased significantly, which indicated that although the nutrition of E. sinensis has been lost to a certain extent after overwintering cultivation, its quality and edible flavor have been improved to some extent. After overwintering cultivation, main volatile substances in edible tissues were 1-octene-3-ol, furfural, hexanal and 2-pentylfuran, indicating a relatively good volatile flavor. The above results indicated that the nutrition of E. sinensis will be lost to a certain extent after overwintering cultivation, and the quality and edible flavor have been improved. The results provide some references for the overwintering cultivation of E. sinensis.

Abstract:The effects of dietary palmatine on the growth performance, antioxidant capacity and non-specific immunity of GIFT Strain of Nile tilapia (Oreochromis niloticus) were investigated. A basal diet was supplemented with increasing palmatine to formulate five diets containing 0, 0.01%,0.02%,0.04% and 0.08% of palmatine. Juveniles GIFT with initial mass of 0.50 g were fed experimental diets for 12 weeks. The results showed as follows:there was no significant difference in final mass, weight gain rate, specific growth rate and feed conversion ratio among all the groups (P>0.05). With the increase of palmatine, the serum activity of AKP and T-AOC showed an increasing trend, and reached the highest value in 0.08% group. The SOD activity in 0.04% group was significantly higher than that in other groups (P<0.05), and the activity of MDA in palmatine groups was lower than that in the control group. The liver activities of SOD, AKP and CAT were significantly higher in palmatine group than those of the control group(P<0.05). The activity of T-AOC showed an upward trend with increasing of palmatine concentration, and there was no significant difference among the palmatine groups(P>0.05). The liver activity of GSH-Px was significantly higher in 0.08% palmatine group (P<0.05), the activity of MDA in palmatine groups was lower than that in the control group. The increase in activities of LZM and C4 in serum and expression levels of IL-1β,TNF-α in liver,were observed in tilapia fed the diets supplemented with palmatine. The phagocytic activity of macrophages was significantly higher in 0.04% palmatine group (P<0.05). Under the present experimental conditions, the addition of 0.04% to 0.08% of palmatine can maintain good growth performance and effectively improve antioxidant capacity and non-specific immunity of GIFT.

Abstract:Residual characteristics and ecological risk of glyphosate in the culture environment of Macrobrachium rosenbergii(M. rosenbergii)were studied. From May to October 2019,the concentrations of glyphosate in aquaculture water,sediment and ridge soil samples of three M. rosenbergii ponds in Jinshan District of Shanghai were monitored,and the ecological risk of glyphosate in aquaculture water and sediment was assessed by the risk quotient method.Results show that the detection rate of glyphosate in aquaculture water was 46.7%,and the maximum residue value was 57 μg/L. The detection rate of glyphosate in culture pond sediment and ridge soil was 83.3% and 77.8%,and the maximum residue value was 1 149 μg/kg and 5 057 μg/kg,respectively. The results of ecological risk assessment showed that the ecological risk level of glyphosate in aquaculture water to the sensitive organisms was mainly no obvious risk and medium risk, while the ecological risk levels in sediment were mainly medium risk and low risk. Research shows that the residual level of glyphosate in the culture environment of M. rosenbergii in Jinshan was at the middle level compared with other areas at home and abroad,and the main source was the use of glyphosate in pond ridge weeding.The residual glyphosate in aquaculture water and sediment had potential risks to M. rosenbergii.

Abstract:To clarify the distribution and abundance of Coilia nasus larvae and juveniles,8 stations were set along the southern branch of Yangtze River Estuary from June to October 2018 and compared with the same period result of 2014 and 2015. A total of 4 611 individuals of Coilia nasus larvae and juveniles were collected in the 58 trawls at the spring tides in the surface layer by a larval net (1.3 m mouth-diameter, mesh aperture 0.5 mm). The average density was 0.123 ind./m³. The body length ranged from 3.10-61.74 mm,with developmental stages from preflexion larvae stage to juvenile stage. The most dominant developmental stages was preflexion larvae whose body length ranged from 3.10-18.12 mm, accounting for 86.18% of the total number, followed by flexion larvae whose body length ranged from 4.90-24.05 mm for 8.50%, postflexion larvae whose body length ranged from 9.75-30.36 mm for 4.60% and juveniles whose body length ranged from 24.22-61.70 mm for 0.72%. A total of 4 211 individuals of Coilia nasus were collected at flood tide during the day, the average body length was 11.18 mm,the average density was 0.169 ind./m³. 339 individuals of Coilia nasus were collected at ebb tide during the day, the average body length was 10.52 mm and the average density was 0.029 ind./m³. At St.8, the average density was 0.005 ind./m³ at flood tide and 0.002 ind./m³ at ebb tide at night. Development stage showed a similar tendency and preflexion larvae were dominant in 2015 and 2018, however, yolk-sac larvae were dominant in 2014. Coilia nasus larvae and juveniles were mostly collected from June to August each year, and rarely collected from September to October. The density was not significantly different among stations.

Abstract:Based on the combined sequences of mitochondrial Cytb and COI gene, the genetic diversity and population historical dynamics of Zacco platypus from the Sha River and the Juma River of the Baiyangdian Basin were analyzed. The results showed that 45 haplotypes were detected in 141 samples, and two of them were shared between the two populations. The haplotype diversity and nucleotide diversity of the Juma River (JMH) population (h=0.712 0, π=0.0118 2) were higher than those of the Sha River (SH) population (h=0.451 4, π=0.003 13). The analysis of molecular variance (AMOVA), genetic differentiation index (F_ST) and phylogenetic tree revealed that there was no obvious genetic differentiation between the two populations. The variation within the population (96.43%) was greater than that between the populations, and there was a large gene flow (6.745) between the two populations. Neutrality test and mismatch analysis showed that the SH population and the JMH population had not experienced population expansion. Bayesian skyline plot (BSP) indicated that the JMH population experienced population expansion before 0.004 million years, and the SH population remained stable. The effective population size of the Baiyangdian Basin experienced population expansion before 0.175 to 0.125 million years, and then remained stable. Combined with haplotype network and phylogenetic tree, the SH population has experienced the founder effect. According to the evolution rate of Cytb gene of Cyprinidae from 0.84% to 1.00% per million years, the divergence time of the two populations is estimated to be 0.089-0.067 million years ago.

Abstract:According to the coastal survey of Zhejiang Province from 2014 to 2016, the Uroteuthis edulis was selected as target species, using boosted regression tree(BRT) to determine the weight of different environmental factors, and also utilize the arithmetic mean model (AMM) and geometric mean model (GMM) to construct the multifactor habitat suitability index (HSI) model. The results showed that the suitable range of sea surface temperature (SST), sea surface salinity (SSS), chlorophyll-a (Chl.a) and dissolved oxygen (DO) in spring for U. edulis habitat area was 22-24℃, 34-36, 0.5-1.5 mg/m³, 8-10 mg/L, respectively; the suitable range of SST, SSS, Chl.a and DO in summer for U. edulis was 23-24℃, 31-34, 0.5-1.5 mg/m³ and 7-11 mg/L, respectively, little seasonal variation was observed; the results of BRT showed that SST was the most important environmental factor, and the other factors ranked as DO, Chl.a and DO, respectively. The spatiotemporal distribution U.edulis is:HSI in spring is relatively low, and occurred in the southern area (27°N-29°N); in summer, HSI is relatively high and often occurred in the northern area (30°N -31°N). Compared with two different algorithms, GMM had lower AIC value than that of AMM, so GMM is more suitable for the habitat suitability study of U. edulis. The optimal habitat distribution of U. edulis in the coast of Zhejiang Province is closely related with some factors, such as the oceanographic variation and current change.

Abstract:The southern bluefin tuna (Thunnus maccoyii) is a highly migratory species, mainly distributed in the waters from 30°S to 50°S in the southern hemisphere, and it is one of the species with the highest economic value among the tunas. Currently the Commission for the Conservation of Southern Bluefin Tuna (CCSBT) is the only regional fisheries management organization (RFMO) regulating this species. The sustainable use of this resource has drawn increasing attention from the international community, which is also a challenge to CCSBT. Combined with the distribution of southern bluefin tuna resources, status of resources exploitation and CCSBT conservation and management measures, the challenges facing the sustainable development of southern bluefin tuna fisheries are discussed. It is though that by implementing a series of maintenance and management measures effectively CCSBT has curbed the decline trend of southern bluefin tuna resources and its biomass has showed increasing signs in recent years, but still faces such challenges as IUU fishing, effective implementation of management measures, full and effective monitoring of incidental catch or bycatch by non-member fishing fleets within the jurisdiction of other regional tuna fisheries management organizations, improvement of catches statistics, etc. The suggestions on quota allocation, improving data quality, cracking down on IUU fishing, implementation of the minimum observer coverage and properly solving the problem of SBT bycatch within the overlapping areas between CCSBT and other t-RFMO. The result can provide reference for relevant enterprises and fishery managers who want to study or understand CCSBT fishery.

Abstract:In order to explore the selectivity of different mesh size codends for Trichiurus lepturus, the covered net method was adopted, and selection experiments were carried out with 5 different mesh sizes(35,45,55,60 and 65 mm) codends on canvas spreader stow net. The Logistic selection model was used to fit the selectivity curve of Trichiurus lepturus and the model parameters were estimated by the maximum likelihood method. The results showed that:(1) 4 265 ind. of Trichiurus lepturus were measured during the experiment, the anal length ranged from 76-305 mm with an average anal length of (167±43) mm; (2) When the mesh size was 35 mm, it was non-selective for Trichiurus lepturus. While the mesh size was 65 mm, the distribution of anal length of Trichiurus lepturus in covered and codend net was basically the same. With the increase of mesh size, the dominant body length of Trichiurus lepturus in the codends was larger than that of the covered nets; (3) When the mesh size for Trichiurus lepturus was 45,55 and 60 mm,its L₅₀ was 171.839,180.562 and 215.905 mm, its SR was 60.402,104.861 and 157.292 mm, respectively. L₅₀ showed a gradual increase trend; (4) The relationship between the codend mesh size(m) of Trichiurus lepturus and L₅₀:L₅₀=2.643m+48.491 (R²=0.748); (5) When the anal length of Trichiurus lepturus is 210 mm, the minimum mesh size of canvas spreader stow net should be 61.1 mm. In summary, combined with the current status of fishery resources, the current minimum mesh size of 55 mm is more appropriate to protect the juvenile Trichiurus lepturus resources, which can achieve the aim of protecting the juvenile Trichiurus lepturus resources.

Abstract:Climate change and climate events have significant impacts on the marine environment, and their impacts vary in time and space. The study looked at sea surface temperature (SST) in five large marine ecosystems (LME) in the northwest Pacific, including West Bering Sea, Sea of Okhotsk, Kuroshio, Oyashio, and the Sea of Japan, and the temporal and spatial trends of SST and their influences under the pacific decadal Oscillation (PDO) with El Niño and La Niña were analyzed. It was found that the SST of the other four large marine ecosystems, except the West Bering Sea, rose sharply around 1987, showing two changing patterns. After removing the long-term changing trend of SST, it was found that the SST of the five LMEs fluctuated up and down with time without regular periodic changes, but it was closely related to the El Niño and La Niña events. According to the spatial distribution of water temperature, the SST of each region showd a trend of increasing gradually from north to south, but the trend of increasing temperature was different. The SST of the whole region in West Bering Sea was increasing, and the cooling region was around Sakhalin and Hokkaido in Japan.

Abstract:In the process of building a maritime power, the study of fish morphological characteristics and fish swimming drag reduction mechanism is crucial to the design and complex swimming behaviour of bionic robotic fish. In this study, taking Dasidicus gigas as the research object, through the visual image acquisition of the samples of the fish, the external contour equations and 3D simplified model of the fish body were established based on the length of the biological characteristics. The analysis shows that the curve fitting method reduces the measurement error caused by the relaxation and deformation of the muscles in different body parts; the analysis shows that the simplified model of bionic squid based on contour equation has lower travel resistance when swimming at high speed, and the drag force coefficient is between 0.000 4 and 0.001 1 at a speed of 13.89 m/s, and the importance of morphology in the mechanism of drag reduction is revealed; this posture of the squid at high speed provides a fluid morphological basis for the squid The biomorphic external profile and CFD methods provide reference for further design and research of the biomimetic squid.

Abstract:In order to improve the accuracy of feeding boats in shrimp and crab ponds, reduce energy consumption, and increase stability and reliability, a design and hydrodynamic simulation experiment is proposed for the three-blade propeller of feeding boats in shrimp and crab ponds. According to the hull size and the upper limit of overall power consumption, the propeller diameters of the three suitable shrimp and crab pond feeding boats were set to be 0.05, 0.06 and 0.07 m, respectively, and the theoretical equation of the ship's propeller jet and the coordinate equation of the blade edge point are as follows:Basically, a three-dimensional blade curve is generated from the three-dimensional coordinates of the blade edge to establish a three-dimensional model of the propeller. Using Ansys CFD software, the Reynolds average Navier-Stokes (RANS) equation and the SST k-ω turbulence model were used to construct a hydrodynamic simulation experiment, and the error between the maximum axial jet velocity and the average axial jet velocity of the propeller was analyzed. The relationship between blade section pressure, rotation speed and average axial jet velocity was analysed to obtain the propeller with the best open water performance. Through the shrimp and crab pond field experiments, the error between the actual ship speed and the maximum axial jet velocity was analyzed to verify the reliability of the propeller design. At the same time, it met the requirements of the shrimp and crab pond feeding boat speed, hull thrust and overall power consumption. Taking the working efficiency of the propeller as the experimental index, the actual working efficiency of the propellers of different diameters at different speeds was compared. The results show that the design method for the propeller of the shrimp and crab pond feeding boat is feasible. The error between the actual ship speed and the maximum axial jet velocity is less than 10%. At the same time, the shrimp and crab pond feeding boat is equipped with a 0.07 m diameter propeller. When the rotating speed is 3 500 r/min, the working energy consumption of the propeller is 135 W, the highest average ship speed is 1.46 m/s, and the working efficiency reaches 70.9%.

Abstract:Frozen storage is one of the methods used for aquatic product preservation. Compared with other preservation methods, frozen storage at low temperature can protect the quality of aquatic products better, so it has become one of the most popular preservation methods at present. However, due to the fluctuation of temperature and the destruction of the tissue structure of aquatic products at low temperature, a series of changes in the quality of aquatic products inevitably happened in the freezing process, such as lipid oxidation, protein freeze denaturation and texture change. The influence of frozen storage on the myofibrillar protein of aquatic products was reviewed. The contents included the influence factors of protein frozen denaturation, the physical and chemical properties changes of myofibrillar protein under the frozen storage condition, the mechanism of protein frozen denaturation, and some measures to control the protein frozen denaturation were summarized finally. It aimed to provide for the application of the frozen storage technology in aquatic products and for the study of effect of frozen storage on the myofibrillar protein.

Abstract:In order to study the effect of thawing methods (microwave thawing, flowing water thawing, normal temperature thawing, and low temperature thawing) on the quality of Ophiocephalus argus, the thawing method that has the least influence on the quality of Ophiocephalus argus was determined by analysing the change of the loss rate of thawing, water holding capacity, myofibrillar protein concentration, volatile basic nitrogen (TVB-N), thiobarbituric acid (TBA) and texture indicators, combined with Fourier infrared spectroscopy and sensory evaluation. It was found that:microwave thawing consumed the shortest time, followed by flowing water thawing, but the rate of succus loss was the largest and the water holding capacity was the weakest after microwave thawing; The results of various indicators after normal temperature thawing were relatively poor; The rate of succus loss was smallest and the water holding capacity was the strongest after low temperature thawing, and TVB-N value and TBA value were the smallest. In addition, the fish chewiness and hardness were better after low temperature thawing, and the sensory evaluation was the best, but the thawing at low temperature took the longest time. The quality of the fish meat after flowing water thawing was second only to low temperature thawing, but the thawing time was about 1/3 of low temperature thawing. Based on the actual production situation and economic benefits, flowing water thawing is more suitable as an industrial thawing method for Ophiocephalus argus. This research can provide a theoretical basis for the raw material processing and processing of Ophiocephalus argus and the development of high-quality products.

Abstract:The aim of this study was to investigate three kinds of different antifreeze agents on quality and nutrition of Litopenaeus vannamei during freezing and thawing (F-T) cycles. Fresh samples were immersed in 30 g/L sucrose sorbitol (SS), 30 g/L sodium tripolyphosphate (ST) and 30 g/L carrageenan oligosaccharides (CO) solutions for 2 h, respectively, with samples immersed in sterile water for 2 h as the control group (CK). Treated samples were packed in PE bags in frozen storage, and 6 cycles of the repeated freezing and thawing were simulated. The anti-freezing effects of different antifreeze agents were evaluated by water holding capability (WHC), Ca²⁺-ATPase activity, magnetic resonance imaging (MRI) and Fourier transform infrared imaging (FT-IRI). The nutritional value changes of Pacific white shrimp during F-T cycles were analyzed by the contents of basic nutrional ingredients and amino acids. The results showed that compared with SS and ST samples, the treatment of carrageenan oligosaccharides could effectively inhibit the decrease of WHC, Ca^{2 +}-ATPase activities and basic nutrional ingredients of freeze-thaw samples; According to amino acid analysis, the content of umami amino acids, essential amino acids and total amino acids in CO treated samples were all kept at a high level during F-T periods; MRI and FT-IRI could reflect the changes of protein content and water migration in shrimp directly. In conclusion, the protective effects of carrageenan oligosaccharides on protein, lipid and water of shrimp were significant. It could not only play an important role in water retention and cryoprotective effects, but also keep the better quality and nutrition of Litopenaeus vannamei.

Abstract:In order to explore the change of lipids in the drying process of ready-to-eat shrimp, the samples of fresh shrimp, cooked, dried for 2 h and dried for 4 h were taken respectively, and the total fat content, lipid composition, fatty acid composition, acid value(AV), peroxide value (POV), thiobarbiturate acid reacting substances(TBARS) were analysed. The results showed that the total fat content of fresh shrimp was 8.74 g/100 g (on dry basis), which did not change significantly during cooking and drying (P>0.05).There was a significant change in lipid composition, with a significant decrease in the ratio of triglycerides and free fatty acids after cooking (P<0.05), while the proportion of phospholipids increased significantly (P<0.05).In the drying process, the proportion of phospholipids showed a downward trend, the proportion of free fatty acids showed an upward trend, while the proportion of cholesterol was relatively stable. The composition of fatty acids changed less in the process, in which the content of polyunsaturated fatty acids decreased in the drying stage and the content of saturated fatty acids was increased relatively. During shrimp drying processing, POV shows a trend of first rising and then decreasing, while AV decreases sharply after cooking, while increases after drying and TBARS continues to rise. Thus, cooking and hot air drying during shrimp drying will affect the proportion of lipid components, and cause the oxidation and decomposition of lipids. The theoretical reference is provided for the optimization, quality control and flavor formation of ready-to-eat shrimp drying process.

Abstract:In order to improve the dissolution of astaxanthin from Haematococcus pluvialis powder, a self-emulsifying drug delivery system was used. The pseudo ternary phase diagram method was used to screen the best composition of the liquid self-emulsifying drug delivery system, and the unextracted Haematococcus pluvialis powder was used to prepare astaxanthin-containing self-microemulsion, and to conduct in vitro evaluation. Taking oil phase, emulsifier, and co-emulsifier dosage as influencing factors, average particle size, polydispersity index (PDI), and drug loading of astaxanthin in Haematococcus pluvialis powder as evaluation indicators, response surface methodology was used to optimize the prescription. Then, the appearance, particle size, PDI, Zeta potential, drug loading, and dissolution of the self-microemulsion were investigated. The best prescription is oil phase (glyceryl triacetate) dosage of 5%, emulsifier (Tween 80) dosage of 67.86%, and co-emulsifier (polyethylene glycol 800) dosage of 27.14%. Under the transmission electron microscope, it was observed that the microemulsion was distributed in a spherical shape with uniform size. The average particle size was (50.32±0.33) nm, PDI (0.113±0.02), the Zeta potential was(-14.6±0.06) mV, and the astaxanthin drug loading was (3.06±0.23) mg/g. The self-microemulsion of Haematococcus pluvialis powder containing astaxanthin was simple to prepare, which increased the solubility of astaxanthin in water, and was conducive to gastrointestinal absorption. The system has good stability and has broad application prospects in food and drug industry.