Abstract:Dmrt1 is one of the most important members of the Dmrt family and plays an important role in germ cell differentiation and sex regulation. To explore its regulatory expression mode in the sex differentiation of the scallop Patinopecten yessoensis, we analyzed the sequence characteristics of P. yessoensis Dmrt1 using bioinformatics methods. The expression of Dmrt1 in different tissues was detected using semi-quantitative reverse-transcription PCR (RT-PCR). Quantitative fluorescence RT-PCR (qRT-PCR) and in situ hybridization were used to reveal temporal and spatial expression changes of Dmrt1 in the four stages of gonadal development (proliferation stage, growing stage, mature stage, emission stage). The results showed the following: the sequence of P. yessoensis Dmrt1 contains the DM domain shared by Dmrt family; P. yessoensis Dmrt1 sequence had high homology with Pecten maximus, compared with multiple sequences of other known species; the positive signal detected by in situ hybridization, was mainly located in the cytoplasm of germ cells; and qRT-PCR showed that the expression level of Dmrt1 was significantly higher in the testis than in the ovaries during the growing and mature stages. However, there was no significant change in the ovarian development cycle and the expression level of Dmrt1 remained low. In addition, Dmrt1 transcripts were weakly expressed in the mantle, gill, kidney, and adductor muscle but not in the hepatopancreas. The results of the study showed that the expression characteristics of Dmrt1 in gonadal and sex differentiation of P. yessoensis are generally similar to those of other animals. We speculated that Dmrt1 is a key gene for the regulation of sex differentiation in P. yessoensis.

Abstract:Siniperca chuatsi is an economically important freshwater fish species cultivated in China. Infectious spleen and kidney necrosis virus (ISKNV) is the main causative agent of disease in S. chuatsi and causes huge economic losses in aquaculture. Viruses depend on cellular metabolisms for rapid replication and proliferation, and metabolomics analyses have revealed that the carbon flux of glutamine metabolism increases in ISKNV-infected cells. Previously, ISKNV has been reported to up-regulate the expression of glutaminase (GLS) and glutamate dehydrogenase (GDH) genes in host cells. These enzymes mediate glutamine metabolism and are necessary for the production of high-titer ISKNV particles. However, the mechanism of ISKNV-induced glutamine metabolism remains unclarified. The silent mating type regulation 2 homolog 3 (SIRT3) is an NAD+ -dependent deacetylase that regulates cellular metabolic conditions and participates in biological activities including cell cycle, mitochondrial ageing, and energy production. SIRT3 has been widely reported to respond to nutrient deficiencies and participate in cancer progression by regulating glutamine metabolism. The metabolic status of virus-infected cells is very similar to that of cancer cells, suggesting that SIRT3 may play a regulatory role during ISKNV infection. To clarify the potential mechanistic link between ISKNV and glutamine metabolism, we analyzed cloned sequences of S. chuatsi SIRT3 and detected expression of SIRT3 in different tissues of S. chuatsi. Then, the time-dependent expression patterns of the S. chuatsi SIRT3 in vitro and in vivo after ISKNV infection were assessed using real-time fluorescent quantitative PCR (qRT-PCR) and western blotting. Finally, the effects of SIRT3 on glutamine metabolism and the proliferation of ISKNV in host cells were analyzed by regulating the expression and the activity of SIRT3. Results showed that the S. chuatsi SIRT3 encoded 449 amino acids that showed high conservation. Expression of SIRT3 in 12 tissues of S. chuatsi was detected by qRT-PCR, with the maximum expressions obtained from the hind kidney. Moreover, the expression of SIRT3 was lower in the spleen, the target organ of ISKNV infections. In vivo and in vitro infection tests results showed that ISKNV infection significantly increased the expression of SIRT3 in S. chuatsi spleen and brain cells and that the time-dependent expression pattern of SIRT3 in spleen and brain cells was similar. Subsequently, we found that the expression of GLS and GDH, the copy number of the ISKNV genome, and the titer of ISKNV significantly increased in ISKNV-infected cells treated with 7 μmol/L honokiol and significantly decreased in ISKNV-infected cells treated and transfected with 10 μmol/L 3-TYP and siRNA-SIRT3, respectively. From the results described above, ISKNV infection was shown to induce the reprogramming of glutamine metabolism via SIRT3, suggesting that SIRT3 may be an effective target for antiviral therapy.

Abstract:The karyotype of fish plays an important role in the preservation of germplasm resources, identification of genetic relationships, exploration of evolutionary processes, construction of genetic maps, and fish classification and breeding. Pseudocaranx dentex is a new target for aquatic resource development, with high economic and breeding value. However, little is known about its genetic background. In this study, chromosome samples from gill and fin tissues of P. dentex were prepared by the hot air-drying method. Karyotype was subsequently analyzed by Giemsa staining. The karyotypes of 106 metaphase cells in four P. dentex juveniles were analyzed. The results showed that the mitotic phase with 48 diploid chromosomes accounted for 86.79% of the observed mitotic phases, all of which were telocentric chromosomes; the karyotype formula was 2n=48t; the number of chromosome arms was NF=48; the relative size of the chromosomes in this species varied from 5.921% (±0.276%) to 2.052% (±0.210%). No heteromorphic sex chromosomes were observed. Neither satellite nor secondary constrictions were observed either. This is the first study on the characteristics of karyotype of fish from the genus Pseudocaranx, compared with 34 species from 15 other genera of the family Carangidae. The karyotype of P. dentex is consistent with the karyotype characteristics of typical high-level groups, according to the evolution of teleost chromosomes. This study provides basic data on cytogenetic characteristics and evolution processes for the effective protection and rational development of this high-quality resource, P. dentex.

Abstract:Sciaenidae species have been an important focus of global marine fisheries and mariculture for a long time owing to its delicate meat, delicious taste, and high corresponding economic value. At present, several species of the family have been successfully cultivated in China, such as Pseudosciaena polyactis, Megalonibea fusca, Nibea diacanthus, Collichthys lucidus, and Sciaenops ocellatus, but none are suitable for freshwater aquaculture in China. Among the 70 genera with 270 existing species of Sciaenidae, only a few are freshwater species, including Boesemania microlepis from Southeast Asia and Aplodinotus grunniens from the Americas. A. grunniens is commonly known as the freshwater drum, topuche, or sheepshead. Freshwater drum have several advantages such as fast growth, good meat quality, no intermuscular spines, and strong adaptability. It is suitable for freshwater and brackish aquaculture in most parts of China and has a broad market prospect. In terms of reproduction biology, embryonic and larval development is one of the key research agendas. Understanding the development characteristics and timings of fish embryos is helpful for improving hatching and survival rates of larvae. At present, there are no data available on embryonic and larval development of freshwater drum for domestic cultivation, and foreign research has not been systematic owing to limitations in artificial breeding technology. This study on artificially reared freshwater drum specimens is the first to obtain fertilized eggs by manual stimulation with oxytocin. Subsequently, the sequence and morphological characteristics of developing embryos of freshwater drum were recorded and described in detail. We believe that our results will enrich the biological data on early development and provide theoretical guidance for the artificial breeding of freshwater drum. The results showed that all studied males of the species were sexually mature, while most females were sexually mature after 3 years of artificial cultivation and can spawn more than once during a spawning season. Artificial reproduction could be realized by means of enhanced cultivation and manual oxytocin stimulation. The spawning duration of freshwater drum was approximately 27 h (23–24 ℃). Mature eggs were slightly yellow with an average diameter of 1.07 mm (SD= 0.04). Newly fertilized eggs of freshwater drum were spherical, pelagic, translucent, and non-adhesive with only one concentric drop of oil of 0.66 mm (SD = 0.02). There were 2–3 drops of oil of different sizes among fertilized eggs. The diameter of fertilized egg expanded to 1.41 mm (± 0.03). The embryonic development of freshwater drum can be divided into 7 phases and 29 periods, including: disk formation, cleavage, blastocyst, gastrula, neurula, organ formation, and incubation. Eclosion started at 25.5 h post-fertilization when larvae had attained a length of 2.88 mm (SD = 0.10). The morphologic characters recorded in the study were similar to those of Sciaenidae species in general. The diameter of the eggs and the length of the larvae for freshwater drum were larger than those of other Sciaenidae species such as Miichthys miiuy, Nibea albiflora, N. diacanthus, C. lucidus, and S. ocellatus and the same as those of P. polyactis. The diameter of the drop of oil was obviously larger than that of the other Sciaenidae species mentioned above. This study is the first to report the embryonic development characteristics of freshwater drum under artificial culture and manual oxytocin stimulation and will provide basic data and important references for future implementation of large-scale breeding of the species.

Abstract:To evaluate the therapeutic effect of Magnolol on Aeromonas hydrophila infections, the effects of magnolol on infection results, blood biochemical indexes, liver antioxidant factors, tissue pathology, and inflammation-related gene expression were analyzed based on the construction of a Carassius auratus gibelio infection model. Blank control, infection group, and 2 mg/kg, 8 mg/kg, and 32 mg/kg magnolol treatment groups were set up. The results showed that magnolol treatment could effectively reduce mortality in infected fish, with relative protection rates of C. auratus gibelio treated with magnolol at 60.75%, 71.85%, and 59.95%, respectively. Compared with the infection group, in the treatment groups, ALT, AST, and LDH were significantly decreased, TP and ALB content was significantly increased (P<0.05), CAT and SOD activities were significantly increased, GSH content was significantly increased, and MDA content was significantly decreased (P<0.05). Histopathological results showed that honokiol alleviated congestion of the liver and spleen to some extent and reduced cell necrosis in the kidneys and intestines. In terms of the expression of inflammation related genes, magnolol treatment significantly decreased the expression of MyD88, NF-κB, and TNF-α but significantly increased the expression of TLR-5 (P<0.05). These results indicate that magnolol can reduce mortality from A. hydrophila infections in allogynogenetic crucian carp, reduce oxidative tissue damage, and downregulate the expression of inflammationrelated genes. The results provide a theoretical basis for the application of magnolol in commercial applications.

Abstract:To explore the effects of the orally administered exopolysaccharides derived from Lactobacillus plantarum HS-07 (EPS-07) on the immunity, antioxidative activity, and resistance against Aeromonas hydrophila in Cyprinus carpio. In this experiment, the EPS-07 (250 μg/mL, 500 μg/mL and 1000 μg/mL) were co-cultured with the head kidney cells of C. carpio. The control group was fed sterile saline, and the treatment group was fed different concentrations of EPS-07 (250 μg/mL, 500 μg/mL, and 1000 μg/mL), once a day, for 7 consecutive days, then challenged with A. hydrophila for 24 h. In vitro tests showed that for EPS-07 co-cultured with the head kidney cells of C. carpio, the proliferation ability, phagocytic activity, NO content, and expression of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) and anti-inflammatory cytokines (IL-10 and TGF-β) were significantly increased (P<0.05). In vivo results showed that before infection with A. hydrophila, the NO content and expression of pro-inflammatory cytokines and anti-inflammatory cytokines in EPS-07 serum treatment groups were significantly increased (P<0.05). The content of T-AOC and GSH and the activities of T-SOD, GSH-Px, and CAT in the hepatopancreas of the EPS-07 treatment group were also significantly higher than those of control group (P<0.05), and the content of MDA decreased in a concentration-dependent manner (P<0.05). After A. hydrophila infection, EPS-07 inhibited the release of NO, upregulated the expression of anti-inflammatory cytokines, and downregulated the expression of pro-inflammatory cytokines. In conclusion, EPS-2 has potent immunoregulatory effects at the cellular and host level, which can improve the immunomodulatory, antioxidant effects, and disease resistance against A. hydrophila in C. carpio.

Abstract:To explore the molecular mechanisms of the toxicity of inorganic arsenic on Portunus trituberculatus, we exposed adult female P. trituberculatus to 0.3 mg/L As³⁺ and 0.3 mg/L As⁵⁺ for 96 h. The non-targeted metabolomics method was used to compare and analyze the changes in the composition and content of metabolites in gill tissue. Compared with the control group, a total of 100 and 59 differential metabolites were obtained in the As³⁺ and As⁵⁺ exposure groups, respectively. According to the physiological functions of the afore-mentioned metabolites and the analysis of their corresponding metabolic pathways, it is speculated that As³⁺ upregulates proline, arginine, ornithine, lysine and other amino acids, and eicosanoids, glycerophospholipids, and other lipids, leading to disruptions in ABC transporter, amino acid metabolism, arachidonic acid metabolism, digestion and absorption, and aminoacyl tRNA biosynthesis. Toxic effects occur as a result, with As⁵⁺ causing abnormal metabolism of vinyl acetylglycine, N2-γ-glutamyl glutamine, γ-glutamyl glutamate, asparagine-isoleucine, glutamyl isoleucine, prolyl phenylalanine, interference with ABC transporter, amino acid metabolism, and glutathione metabolism. The observations of these toxic effects on P. trituberculatus provide a theoretical basis for future in-depth investigations of the mechanisms resulting from toxic exposure to inorganic arsenic.

Abstract:Purification of discharged aquaculture waste water and nitrogen removal have become essential practices as environment protection policies impose increasingly strict waste water discharge restrictions. To improve the purification efficiency of maricultural waste water, we studied the purification effect of biofilters augmented by different compositions of 3 nitrogen-removing bacteria strains on static and flowing maricultural waste water. Firstly, different compositions of 3 nitrogen-removing bacteria strains, Bacillus hwajinpoensis SLWX₂, Halomonas alkaliphila X₃, and Alteromonas macleodii SLNX₂, which can remove ammonia, nitrite and organic matters in the marine environment were used to strengthen biofilm formation and to purify static waste water, and the best combination was selected according to its removal efficiency of inorganic nitrogen, TN, and CODMn, for the treatment of flowing waste water. The continuous removal of NH₄⁺ -N, NO₂^– -N, and NO₃^– -N from flowing discharged aquaculture waste water was compared with that of naturally formed biofilters. Static waste water treatment results showed that the concentration of NO₃^– -N increased then decreased and that the removal efficiency of inorganic nitrogen and organic matter from the waste water in trial groups was better than that in the control group. Among the treatments, the group of highly concentrated SLWX₂+X₃+SLNX₂ had the best purification effect on all indexes for waste water, and the removal rates of NH₄⁺ -N NO₂^– -N, CODMn, and TN were 100%, 100%, 80.7%, and 59.5%, respectively, after 48 h. In the control group, they were 95.5%, 50.52%, 38.1%, and 13.44%, respectively, and the concentrations of NO₃^– -N kept increasing. The results showed that enhanced biofilm formation by nitrogen-removal bacteria can significantly improve the purification efficiency of biofilters and effectively reduce the concentration of nitrogen and organic matter in waste water from mariculture. The results of the experiment on purification of continuously flowing waste water showed that the concentration of NH₄⁺ -N, NO₂^– -N and NO₃^– -N in the effluent of the experimental groups and the control group was lower than that in the influent. Furthermore, these measurements from the bacteria-augmented biofilm group were lower than those from the natural biofilm and the removal efficiency of inorganic nitrogen in the 10⁶ CFU/mL experimental group was the highest, with the maximum removal rates of 31.6%, 11.33%, and 15.6%, respectively. This was followed by the 10⁵ CFU/mL test group, and the concentration of inorganic nitrogen in the effluent could be maintained at low levels for over 21 days, suggesting that the continuous removal effect of the enhanced biofilm was better than that of the natural biofilm. The results of this study provided a theoretical and technical basis for the application of nitrogen-removing bacteria in the purification of waste water from mariculture.

Abstract:The spectacular scenery of Hani terraces is an intangible world cultural heritage, but in recent years, the deterioration of these terraces, owing to the loss of young adult carp, is becoming increasingly severe, and they require urgent protection. In the present study, we investigated the ecological characteristics of the integrated rice-carp farming system in Hani terraced fields, which will provide a reference for optimizing the technical processes of integrated rice-carp farming systems in Hani terraced fields at different altitudes. From May to August 2019, a survey of the macrobenthos in integrated rice-carp farming terraces at different altitudes (570 m and 1840 m) was carried out at the Hani terraces in Honghe County, Yunnan Province. We investigated the differences in community composition, density, biomass, and diversity of macrobenthos of these Hani terraces. The Jargensen index and Jaccard similarity index were used to compare the similarity of macrobenthos community structures from high and low elevations, and the Shannon-Wiener, Pielou evenness, and Margalef richness indexes were used to evaluate biodiversity. Two-way analysis of variance (two-way ANOVA) was used to identify significant differences in the Shannon-Wiener, Pielou evenness, and Margalef richness indexes, density, and biomass of macrobenthos communities between high and low altitudes. The results showed that. (1) A total of 25 species of macrobenthos were found in low altitude terraces, which belonged to 3 phyla and 3 classes and included 9 species of Oligochaeta, 16 species of Insecta, and 1 species of Gastropoda. A total of 24 macrobenthic species were found in high altitude terraces, which belonged to 2 phyla and 2 classes and included 3 species of Oligochaeta and 21 species of Insecta. Oligochaeta and Insecta were the main macrobenthic groups in high and low altitude terraces, and the species compositions was significantly (P<0.05) different between the two altitudes. The rice pests Chironomus and Tanytarsus were found in terraces at both high and low altitudes. In addition, the rice pest Pomacea canaliculata was found at low altitudes. (2) The Jorgensen index and Jaccard similarity index values indicated differences in the macrobenthic community structure at the two altitudes during the 4 months that the study was conducted. (3) In June and July, the Shannon-Wiener diversity, Pielou evenness, and Margalef richness indexes between the high and low altitudes were significantly different in the same month (P<0.05), while the differences in the other months were not significant (P>0.05). (4) The two-way ANOVA showed that month and altitudes significantly (P<0.05) affected the density of macrobenthos at high and low altitudes and that month significantly (P<0.05) affected the biomass, but there was no significant difference between altitudes (P<0.05). There also was an interaction between density and biomass in month and altitude (P<0.05). The present study showed that altitude and month were the key factors affecting the macrobenthic community structure of the Hani terraced integrated rice-carp farming system at different altitudes. Concurrently, the feeding pressure of carp was also an important factor of differences in the macrobenthic community structure, which reduced the pest biomass in the Hani terraced integrated rice-carp farming system.

Abstract:The species composition, abundance and distribution of ichthyoplankton and their changes are important indicators for the investigation of fishery resources. The abundance of ichthyoplankton affects the early supplement and population dynamics of fishery population. Therefore, carrying out necessary scientific surveys is necessary to understand the species diversity of ichthyoplankton in the central and Southern Yellow Sea. Generally, the larger the sample size is, the closer the survey results are to the true values. Considering the time and cost of the survey, balancing the sample size and data quality is needed to achieve the highest accuracy under a certain sample size. The optimal survey design requires that under certain survey demand and cost conditions, the bias and accuracy of the survey objectives are the highest, and the investigation benefit is maximized. Optimization of the sampling design to obtain accurate and reliable survey data with limited survey cost is important in fisheries-independent surveys. In this study the estimate of species richness of ichthyoplankton was the sampling objective. Based on the ichthyoplankton survey data collected in August (summer), October (autumn) 2014, February (winter) and may (spring) 2015 in the coastal waters in central and Southern Yellow Sea, the effect of different sampling designs on estimation of ichthyoplankton species richness was compared using the computer simulation study. In this study, it is assumed that the original survey data can be used as the “true value” reflecting the species composition and species number of fish plankton in the sea area. This paper mainly compares the effects of different sampling designs on the estimation of ichthyoplankton species richness; when the cost is fixed, the sampling design which can achieve a certain species richness detection rate and has small relative estimation error and relative deviation is selected as the optimal sampling design. The results showed that the detection rate of ichthyoplankton species richness increased gradually with the increase of sampling frequency and the number of sampling stations, and the relative estimation error (REE) and relative bias (RB) of the estimate of ichthyoplankton species richness decreased gradually. Stratified random sampling performed better than simple random sampling, and the design effect (D_e) of stratified random sampling with 4 times a year is 0.766. Under different sampling frequencies, the optimal season combinations were spring, spring-summer, spring-summer-autumn and four seasons, and the corresponding REE and RB values were the lowest among different seasonal combinations with the same frequency, and the species richness detection rates were the highest. If the detection rate of species richness was set at 90%, the optimal number of stations was 80 and 60 for stratified random sampling with 3 and 4 times a year, respectively. The sampling method and optimal season combination under different frequencies were optimized under the premise of ensuring the estimation accuracy and precision, which will provide reference for the further optimization of sampling design for ichthyoplankton survey.

Abstract:Owing to overfishing, climate change, and environmental pollution, the biological and ecological characteristics of the small yellow croaker, Larimichthys polyactis in Haizhou Bay have greatly changed. In this context, the study of the trophic dynamics of the small yellow croaker in Haizhou Bay was conducted to provide a scientific basis for the sustainable use of the small yellow croakers. Bottom trawl surveys in Haizhou Bay and adjacent waters and the stomach content analysis of caught fish was conducted during the autumns of 2011 and 2013–2016. Based on the data collected, Hurdle-GAMMs (Hurdle-Generalized Additive Mixed Models) of the small yellow croaker in the Haizhou Bay ecosystem were built. The model combines the Hurdle model, Generalized Additive Mixed model, and mixed effect model, which can avoid the residual heterogeneity, non-independence, and sample grouping problems of GAM, and can be applied to the trophic dynamics of fish. The major prey species and key environmental factors were selected to examine the trophic dynamics of small yellow croakers. The results showed that predator length, distance from shore, and depth of water were the most important environmental factors for feeding in small yellow croakers. When the body lengths of small yellow croakers were between 80–100 mm and 120–140 mm, their feeding habits changed significantly. In addition, in areas 40–60 km offshore and at depths of 15–25 m, the food composition of small yellow croakers also changed significantly. The spatial variations of feeding in small yellow croakers were closely related to the distribution of prey species, and the variation in their feeding habits were also affected by multiple other factors. These were related to the spatial distribution of key prey species in the environment and interspecies relationships. In addition, the mouth crack, teeth, gill rake, and other feeding organs of small yellow croakers developed gradually with increases in body length. Therefore, the composition of key prey species will also change with increases in body length. In addition, the availability of prey could also affect the distribution of small yellow croakers and alleviate the interspecific competition in the Haizhou Bay ecosystem. The effects of various factors were also correlated with the feeding intensity in the small yellow croaker. Hurdle-GAMMs were proven to be an effective method for exploring the trophic dynamics of species and will provide theoretical support for the conservation and sustainable development of marine fisheries resources.

Abstract:The jumbo flying squid Dosidicus gigas is widely distributed in the eastern Pacific Ocean and has high value as one of the main economic cephalopods in China. This study combined fisheries data for D. gigas off Peru, obtained from the National Data Center of Distant-water Fisheries of China, in the eastern Pacific Ocean from 2012 to 2018, with environmental data including sea surface temperature (SST), sea surface salinity (SSS), chlorophyll-a (Chl-a), net primary production (NPP), photosynthetically active radiation (PAR), eddy kinetic energy (EKE), and sea level anomaly (SLA). We explored the temporal and spatial variation of D. gigas in fishing grounds over annual seasons using maximum entropy models (MaxEnt) to compare the effects of different environmental conditions. The results showed that the focus of fishing moved northward from January to August and southward from September to December. Longitudinally, the focus of fishing moved back and forth between 80°W and 82°W, consistent with changes in the suitability of habitat. Moreover, the key environmental factors selected were different, based on their contribution rate each month, among which SST, SSS, NPP, and PAR had major effects on habitat. According to the optimal environmental ranges obtained from the response curves of these key environmental factors, the range of suitable environments significantly overlapped with that of suitable habitats. The results indicated that the maximum entropy model was highly accurate at predicting the population abundance of D. gigas off Peru, which showed obvious monthly variations and were significantly affected by environmental factors.

Abstract:Fisheries stock assessment is an important prerequisite for formulating sustainable fishery development strategies. Limited data is a common challenge to global fishery stock assessment, with traditional stock assessment methods inapplicable to the stock assessment of data-limited fisheries, because of the need for reliable biological information for accurately estimating species abundance. Owing to limited funding and large datasets required in such surveys, only 1% of fish stocks have had systematic assessments conducted. Therefore, it is difficult to assess the maximum sustainable yields (MSY) or determine allowable catches for most commercial fish species using traditional methods. The development of data-limited methodologies that can evaluate the status of fish stock, biological reference points and biomass in using a small amount of available data and biological information, has become the focus of global regional fishery management organizations and fishery resource scholars. Based on bibliometric analysis, we summarize and review the model structure, model input and output, assumptions, sources of uncertainty, and analysis methods of the following catch-based and length-based assessment models: catch-maximum sustainable yield (Catch-MSY), depletion based stock reduction analysis (DB-SRA), depletion corrected average catch (DCAC), simple stock synthesis (SSS), an extension of Catch-MSY (CMSY), length-based spawning potential ratio (LBSPR), length-based integrated mixed effects (LIME), length-based Bayesian (LBB), and length-based risk analysis (LBRA). The focus and direction of future research are proposed based on this analysis. The results indicate that owing to the characteristics of data-limited fisheries, stock assessment is still in the development stage. If the catch and body length data are available, a model that integrates the two types of data, such as the LIME model and the SSS model, should be considered. It is suggested that the following work should be carried out in future research: (1) to actively carry out long-term, multi-sea, and full-coverage independent surveys to obtain representative sample data; (2) further optimize the existing data-limited methods and comprehensively consider the effect of various factors on the evaluation results; (3) complete and accurate basic biological research is conducted to obtain more accurate historical biological information, thereby reducing the uncertainty of the evaluation results; (4) carry out simulation testing research based on the catch-based model and length-based model to improve the tolerance of the model to statistical bias and data quality issues.