Volume 77, Issue 3, 2025

Permanent URI for this collectionhttps://hdl.handle.net/10524/87854

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Modulation of Growth and Immunity in Carp by Hermetia illucens Larvae induced by Aeromonas hydrophila
Yan, Shiqi; Liu, Junli; Yang, Aixi; Zhou, Maoyuan; Cheng, Jingran; Zhang, Mingzhu; Su, Junfeng; Li, Chenghao; Li, Siming; Wen, Anxiang
This experiment aimed to investigate the effects of Aeromonas hydrophila-induced treatment of black soldier fly (Hermetia illucens) larvae on the growth performance and immune function of the common carp. Aeromonas hydrophila-induced black soldier fly larvae were sterilized and crushed, four diets were prepared by replacing 0% (control group), 10%, 20% and 30% fishmeal of the ration, respectively, and fed to carp (the mean ± SD weight was 48.51 ± 0.47 g) for 30 d. The results showed: (1) The weight gain rate, specific growth rate, and gene expression levels of GH and IGF-1 of carp in 20% and 30% replacement group were significantly higher than those in control group (P<0.05); (2) The plasma lysozyme content in 30% replacement group was significantly higher than those in control group (P<0.05). The plasma acid phosphatase activity and the expression levels of TLR4 and Myd88 in the 20% and 30% replacement groups were significantly higher than those in the control group (P<0.05). The expression level of TLR2 in all experimental groups were significantly higher than those in control group (P<0.05); (3) The numbers of Escherichia coli and Salmonella in the experimental groups were lower than those in control group (P<0.05), while the numbers of Lactobacillus and Bifidobacterium were significantly higher than those in control group (P<0.05). These results suggest that feeding carp with Aeromonas hydrophila-induced larvae of black soldier fly, instead of 10 to 30% fish meal, can significantly enhance their immune capacity and promote growth.
The current situation and sustainable development of Penaeus monodon in South China: A Review
Sun, Zhiwei; Cai, Yunchuan; Qi, Xinyu; Wang, Jieyi; Zhou, Falin; Shi, Jianzhi; Ming, Junchao; Jiang, Song
The three provinces of Guangdong, Hainan, and Guangxi in South China are the primary production areas for Penaeus monodon aquaculture. The combined coastline of these three provinces spans 7,552.74 kilometers, accounting for 23.60% of China,s total coastline length. Compared to Southeast Asia and India, where P. monodon farming is declining due to disease outbreaks and competition with Litopenaeus vannamei, South China remains a key producer by leveraging intensive pond systems and government-supported breeding programs. In 2022, the aquaculture production of P. monodon in these provinces reached 91,200 metric tons, representing 79.79% of the national total; by 2023, this figure increased to 104,200 metric tons, comprising 81.12% of the national output. Currently, the aquaculture area for P. monodon in South China spans approximately 300,000 mu (about 20,000 hectares), with 50,000 mu (about 3,333 hectares) dedicated to high-level pond systems. Statistics indicate that the P. monodon industry supports employment for over one million residents across these provinces. Consequently, the sustainable development of P. monodon aquaculture is critical to both the economic growth and livelihoods of South China. However, the industry faces challenges such as frequent disease outbreaks, low-quality seedling rates, and high farming risks. To investigate the current status, existing issues, and sustainability of P. monodon aquaculture, this study was conducted. It aims to provide a concise overview of the P. monodon industry in South China and offer reference for policy formulation by global aquaculture sectors and relevant government agencies.
Effect of Dıfferent Incubators and Temperature on Artıfıcıal Incubatıon of Crayfısh Pontastacus Leptodactylus (Eschscholtz, 1823) Eggs
AKIN, Mustafa; BAHADIR KOCA, Seval; ATSATAN, Kamil; ÖZDOĞAN, Hasan Batuhan Emre; SEVGİLİ, Hüseyin; DEWİ, Amanda Kusuma
This study aimed to investigate the effectiveness of different temperatures and incubators on the incubation of Pontastacus leptodactylus eggs. Eggs were collected from a total of 150 broodstock with an average weight of 52.59 ± 12.26 g and length of 13.23 ± 1.48 cm. A total of 470 eggs were placed in each incubator. Four different incubator types were used in the experiment, and each group was studied with four replications; 1. Biolife Turbojet Star X6 (biolife), 2. Jar with a flat-screen bottom, 3. Platform with a screen bottom and 4. Aquarium containing a flat-screen chamber. Only incubator number 1 had a water current that moved the egg in a certain vibration, whereas the others (2, 3, and 4) did not move the eggs. All incubators were tested at two different temperatures 15.5 oC and 19.5 oC. In both temperature regimens, a water flow of 19 ml/sec was provided to the tanks containing all incubators. Two-way ANOVA analysis revealed that the influence of temperature was not significant (p > 0.05) in terms of hatching rate, but the incubator and interaction terms were significant (p < 0.05). Significant effects of temperature and incubators without an interaction (p < 0.001) were the case for the stage II survival rate. The best hatching rate was in the Biolife incubators at both temperatures. The highest hatching rate was observed at 15.5 °C (86.74%), followed by 74.68% at 19.5 °C, while the lowest hatching rate was recorded in the aquarium, with no hatching at 15.5 °C. These groups were followed by a platform with 49.57% at 15.5 oC, an aquarium with 42.55% at 19.5 oC, jar with 41.77% at 19.5 oC, a platform with 28.01% at 19.5 oC, and jar with 14.04% at 15.5 oC. The survival rate at the stage II larval was highest in Biolife with 54.82% at 19.5 oC, while the worst was in jars and aquariums at 15.5 oC. Biolife system that moved the crayfish egg during the incubation gave better results at both temperatures. Our recommendation is that egg-moving systems should be preferred for the incubation of crayfish eggs.
Effects of dietary Clostridium butyricum on growth performance, non-specific immunity, intestinal microbiota and disease resistance of Scylla paramamosain
Li, Guiying; Jiang, Jianjun; Cheng, Changhong; Ma, Hongling; Liu, Guangxin; Fan, Sigang; Guo, Zhixun
In this investigation, we examined how Clostridium butyricum influences the growth, innate immune reaction, intestinal microbiota, and disease resistance of Scylla paramamosain. Different concentrations of C. butyricum were sprayed on the feed: 0 (CC), 3.6×104CFU/g (CB1), 3.6×105CFU/g (CB2), 3.6×106CFU/g (CB3), and 3.6×107CFU/g (CB4) over a period of 42 days. The findings indicated that the final weight and specific growth rates of S. paramamosain in the CB2 and CB3 treatment groups were significantly greater compared to the other groups (P <0.05). In compared to the control group, the activities of alkaline phosphatase (AKP), superoxide dismutase (SOD), total antioxidant capacity (T-AOC) and intestinal lipase (LPS) were all elevated, with significant improvements noted particularly in the CB3 group (P < 0.05). Furthermore, the relative expression levels of the IL8 and TNF-α genes in the CB2 and CB3 groups, as well as the GPx3 and SpPO genes in CB3 and CB4 groups were markedly elevated compared to the other groups (P< 0.05). Incorporating 3.6×106CFU/g of C. butyricum into the diet improved the variety of the gut flora in S. paramamosain. Functional analysis conducted through KEGG Pathway Level 2 indicated that the experimental group had a greater abundance of metabolic-related pathways than the control group, with the CB3 group displaying the highest levels. In conclusion, including an appropriate level of C. butyricum within the dietary composition can foster the growth of S. paramamosain, enhance the diversity of gut microbiota, and improve immune function; the optimal concentration identified was 106 CFU/g in the feed.
The Effect of Houttuynia cordata Feeding on the Expression of Anti-SVCV Inflammatory Factors in Common Carp
Li, Zhixuan; Bai, Yaqian; Zheng, Jian; Yang, Yingda; Wang, Jing; Wang, Yake; He, Xianlin; Zhang, Chi; Zhang, Baowei; Zhang, Jiaqi
Spring viremia of carp virus (SVCV), a negative-sense single-stranded RNA virus belonging to the genus Sprivivirus in the family Rhabdoviridae, poses a significant threat to carp aquaculture due to its high virulence. Currently, there are no specific therapeutic drugs available for this pathogen. Driven by the concept of sustainable development in green fisheries, developing environmentally friendly antiviral agents has become a hot topic in the industry. This study systematically evaluated the effects of Houttuynia cordata Thunb., a plant with broad-spectrum pharmacological activity. It is used in both food and medicine for its immune regulation and antiviral capabilities. In this experiment, 30 healthy common carp (Cyprinus carpio, with a body weight of 20 ± 5 g) were randomly divided into an experimental group (fed with feed containing 3% Houttuynia cordata extract) and a control group (fed with regular feed). After three weeks of feeding, a challenge experiment was conducted. Real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) detected that the mRNA expression levels of key inflammatory factors, such as IL-10 and TNF-α, were significantly upregulated in the experimental group compared to the control group (p<0.01). In contrast, the relative expression levels of NF-κB varied across various tissues. This study clarifies the molecular mechanism by which Houttuynia cordata extract enhances the innate immune response of common carp by promoting anti-inflammatory factors. It provides crucial experimental evidence for developing SVCV-resistant agents based on plant-derived active components, supporting green and sustainable aquaculture practices.
Analysis of the Impact of Aquaculture and Agriculture on Food Security under the Pressure of Pollution
Alsaleh, Mohd; Abdul-Rahim, A.S.
Both aquaculture and agriculture are essential for food security in Europe, but they face different challenges and opportunities. A sustainable and balanced approach that considers both sectors is needed to ensure that Europe can meet its food needs while protecting the environment and promoting economic growth. This research is aimed at studying the economic analyses of the effect of aquaculture versus agriculture production on future food security in the EU27 region from the era between 1990 and 2023. Resolve challenges of endogeneity, employing econometric estimators such as the robust least squares (RLS), two-stage least squares (2SLS), and ordinary least squares (OLS), producing crucial insights. The analysis reveals that in the EU27 region, agricultural production has a higher impact than aquaculture production on influencing food security. Moreover, in the EU13 developing countries, aquaculture production has a higher impact on food security than in the EU14 developing countries. On the other hand, in the EU14 developed countries, agriculture production plays a significant role in food security in comparison with the EU13 developing countries. From another perspective, economic growth, governance, and fossil fuel consumption variables play a significant role in food security in the EU13 members compared with the EU14 members. Based on the study's findings, policymakers in the EU27 region are advised to provide policies targeted at advancing the aquaculture sector top priority to achieve food security in the future, especially in EU14 developed countries. Additionally, this study suggests that decision-makers in the EU13 members need to improve the efficiency of agriculture production to meet the food security targets.
From Climate Change to Occupational Risks: The Vulnerability of the Fisheries Sector to Climatic Accidents
Alsaleh, Mohd; Xia, Tian; Abdul-Rahim, A.S.
With the increase in global average temperature due to climate change, a large number of workers are exposed to high-temperature working environments. Therefore, this study examines the impacts of fisheries production, consumption of fossil fuels, economic growth, and governance on climatic occupational accidents amid global change in the EU from 1990 to 2022. Using the novel Moments Quantile Regression (MMQR) method with fixed effect components, the findings showed a significant link between the expansion of the fisheries industry and climatic occupational accidents at higher quantiles. The results also showed that developed members in the EU14 believe that the expansion of the fisheries industry has a bigger impact on climatic occupational accidents than developing countries in the EU13. Regarding how the use of fossil fuels affects maritime climatic occupational accidents, it has been shown that the majority of this variable's quantiles are positively correlated with the prevalence of threats. However, in the original and emerging EU13 and EU14 countries, economic development lowers climatic occupational accidents, supporting the growth hypothesis for fisheries-producing nations. The relationship between climatic occupational accidents and governance was found to be significant in the first through the ninth quantiles across the EU27 nations.
Resilience and Intentions of Fishermen Transitioning to Ecological Farming: Insights from China’s Yangtze River Basin
Zheng, Jianming; Wang, Xueming; Yang, Yang; Jiang, Qijun
The study examines the extent of livelihood resilience in relation to the fishing ban, as well as the readiness of various types of fishermen to embrace ecological farming under different incentive structures. It simulates the varying willingness to adopt ecological farming across diverse environmental contexts within China. The results indicate that: (1) Self-organization ability, particularly the emphasis on subsidy benefits and policy awareness, could independently lead to interpretive outcomes. (2) Three pathways can motivate fishermen to adopt ecological farming: self-organization-dominant, self-organization-learning driven, and buffering-learning driven. Concurrently, three categories of factors impede the enhancement of fishermen's willingness to engage in ecological farming: learning inhibition, self-organization-learning inhibition, and buffering-self-organization inhibition. (3) Under specific conditions, self-organization ability can be substituted by the conditional combination of the other two abilities to bolster the willingness of fishermen to adopt, in a manner akin to "all paths leading to the same destination." (4) Heterogeneity analysis demonstrates that livelihood resilience exerts a more significant influence on the willingness of fishermen in the Yangtze River Basin to participate in ecological farming, particularly in areas with lower economic development levels. Moreover, this resilience has a more pronounced effect on the intentions of older generations.
Microbial community structure and function in aquatic environments during the overwintering cultivation of juvenile Apostichopus japonicus
Yao, Miaomiao; Song, Limin; Wang, Yibo; Qi, Guoshan; Ren, Hai; He, Zhenping; Yu, Shanshan; Wang, Qinglin; Zhao, Chunlong
To characterize microbial community structure and function in aquatic environments during the overwintering cultivation of juvenile Apostichopus japonicus, we analyzed water samples from a representative industrial indoor aquaculture facility in Tangshan, Hebei Province. We assessed water quality by measuring key physicochemical parameters and employed 16S rRNA gene sequencing to profile microbial composition and functional traits. Our results revealed that ammonium nitrogen (NH₄-N) levels in surface water during the late pond-transfer stage in Workshop 2# reached 1.494 mg·L⁻¹, significantly exceeding those observed in other samples (P<0.05). Microbial richness in Workshop 1# peaked during the early pond-transfer phase, significantly increasing relative to other timepoints within the same workshop (P<0.05). At the phylum level, Proteobacteria and Bacteroidetes dominated across all samples. Firmicutes represented the third most abundant phylum during early pond-transfer stages, while Actinobacteria ranked third in routine aquatic water. Sulfitobacter and Polaribacter were prevalent at the genus level during the early pond-transfer phase. Of particular concern, Vibrio showed the highest relative abundance in mid-phase pond-transfer water from Workshop 1#, indicating a potential disease risk. These findings elucidate microbial community shifts in A. japonicus_ aquaculture systems during overwintering, offering both theoretical insights and practical recommendations for optimizing industrial-scale aquaculture management.
In vitro antibacterial activity of 40 Chinese herbal medicines against three aquatic pathogenic bacteria
Zhu, Nengbin; Qu, Xuelei; Gao, Feiyang; Wangkahart, Eakapol; Liang, Qianrong; Zhang, Lin; Liu, Lihe; Wang, Rui; Xu, Hongsen; Ding, Huiping
Chinese herbal medicines could be an alternative treatment for antibiotics against fish bacterial disease. The present research was carried out to investigate the antimicrobial potential of 40 herbs against Edwardsiella tarda, Streptococcus iniae and Klebsiella pneumoniae. Firstly, the anti-bacterial activity of forty herbal aqueous extracts (HAEs) was determined using the plate perforation method on brain heart infusion (BHI) agar. Then, effective HAEs were selected to detect the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against the pathogenic bacteria through the micro broth dilution method. Lastly, the inhibitory effects of HAEs combination were also assessed. The results showed that Caesalpinia sappan, Fructus mume, Rhus chinensis and Punica granatum could effectively inhibit all strains of the test bacteria, with the inhibitory circles in 15.00–17.00 mm diameter, MIC and MBC ranging from 31.25 to 62.50 mg/mL and 62.50 to 125.00 mg/mL, respectively. Among the compound of HAEs, the combination of Fructus mume + Rhus chinensis exhibited the most potent antibacterial efficacy against E. tarda and S. iniae, producing inhibitory circles of 19.5±0.41 mm and 19.5±0.41 mm, respectively. The MIC and MBC of this combination against E. tarda were 15.625 and 31.25 mg/mL, whereas, the MIC and MBC of this combination against S. iniae were 7.8125 and 15.625 mg/mL. The compound of C. sappan + F. mume showed the most potent antibacterial efficacy against K. pneumoniae, with inhibition zone diameter, MIC and MBC were 24.50±0.41 mm, 7.8125 mg/mL and 15.625 mg/mL, respectively. Overall, the results indicate that C. sappan, F. mume, R. chinensis and P. granatum showing significant potential for inhibiting pathogens, and their combinations could be a potential alternative to treat the aquatic bacteria diseases.
Internal Control Significantly Improves the Corporate Social Responsibility Performance of Listed Companies in the Agriculture, Forestry, Animal Husbandry, and Fishery Sectors: Empirical Evidence from China
Wang, Junhui; Guo, Hongjia; Jiang, Qingqing; Zhao, Zhuming
This paper investigates whether internal control improves corporate social responsibility (CSR) outcomes and whether ownership concentration moderates this link for China’s agriculture, forestry, animal husbandry, and fishery (AFAHF) listed firms. Using 330 firm-year observations (2010-2021) and firm/year fixed-effects regressions, we find a positive and statistically significant association between internal control and CSR (5% level). Ownership concentration further strengthens this relationship, with the interaction term also significant at the 5% level. Robustness checks using an ordinal internal control measure and adding additional controls yield consistent results. These findings highlight a governance pathway through which stronger internal control supports CSR implementation in resource-based sectors and provide practical implications for regulators and firms seeking to enhance sustainable development in the AFAHF sectors.
Microscopic and submicroscopic observations of the mantle and submicroscopic observations of the gills of oysters (Crassostrea hongkongensis) infected with Polydora
Guo, Changyu; Wang, Jiang-Yong; Sun, Jing-Feng; , Kai-Yuan; Zhao, Jia-Hao; Wang, Zhao-Rui
In order to study the symptoms and pathogenesis mechanism of Crassostrea hongkongensis infected with polychaete ciliates, the polychaete ciliate was identified by molecular identification, the mantle tissues of infected oysters and healthy oysters were observed by light microscope and transmission electron microscope, and the gill tissues of infected and healthy oyster were observed by transmission electron microscope. The symptoms of infected oysters were black mud tubes filling the inner and outer surfaces of the shell, ulceration of the soft body, darkening of the color, atrophy and erosion of the mantle and other tissues, and an increase in mucus. Micropathological changes included tearing of connective tissue, dissolution, disappearing crest protrusions, an increase in secretory cells, Cytoplasmic pyknosis, nuclear membrane rupture, contraction and dissolution of nuclei, and partial or complete disappearance of organelles. Additionally, the secretory cells of infected individuals showed nuclear aberration and some secretory granules overflowed.
Comparative Transcriptome analyses of the molecular mechanisms underlying skin color variations in ocellaris clownfish Amphiprion ocellaris (Cuvier, 1830)
Hu, Jing; Huang, Junhua; Ma, Zhenhua
In this study, we employed high-throughput transcriptomic sequencing technology to analyze the skin color variations among four different strains of clownfish (Amphiprion ocellaris). We compared the differentially expressed genes (DEGs) between the Captive Breeding of A. ocellaris (RS), Australian Geographic Variation of A. ocellaris (AS), Wild-Caught A. ocellaris (YS), and Carnelian A. ocellaris (MS). Furthermore, we conducted Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses to explore the enriched pathways associated with pigment regulation genes. The results revealed that there were 270 common DEGs across the four different strains of A. ocellaris. In comparisons of AS, YS, and MS against RS, the numbers of DEGs that were upregulated and downregulated were 932, 1925, and 1929, respectively. The GO functional annotation analysis across the four comparisons indicated that the DEGs involved in cellular processes were the most numerous. Finally, the KEGG pathway enrichment analysis revealed significant enrichment (p\<0.05) in 11, 10, and 6 unique pathways in RS compared to AS, YS, and MS, respectively. Key biological pathways involved in body color variation included DNA replication, drug metabolism---cytochrome P450 pathways, and pigment biosynthesis. The findings of this study provide new insights into the molecular basis of body color variations among different strains of A. ocellaris and offer theoretical foundations for breed improvement in aquaculture.
Path Analysis and Grey Correlation Analysis of Morphometric Traits to Body Weight of Exopalaemon modestus
Liu, Jiahui; Hu, Zhiguo; Su, Chaoqun; Yao, Gaoyou; Li, Jia; Shao, Wenhui; Dong, Linying; Huang, Rongjing
The Siberian prawn Exopalaemon modestus is a commercial freshwater shrimp with high nutritional value in China. To analyze the influence of morphometric traits on the body weight of E. modestus and identify effective indicators for breeding programs of E. modestus, we analyzed the correlations between 12 morphometric traits and body weight using correlation analysis, path analysis, multiple regression analysis, and grey relational analysis. Path analysis showed that body length (BL), carapace height (CH), carapace width (CW), and abdominal width (AW) significantly affect body weight (BW) directly (P \< 0.05). BL had the most significant direct effect (0.721) on body weight. The total determination coefficients of four significant morphometric traits on body weight were 0.906 (\>0.85), indicating that substantial morphometric traits explained 90.6% of BW variation. The regression equation was constructed as BW=-1.666+0.049BL+0.045CH+0.035CW+0.021AW (P \< 0.01, R² = 0.906). Grey relational analysis identified that the trait most correlated with BW was BL (relational grade = 0.952), followed by carapace length (CL), abdominal length (AL), and CH. Combined with path analysis and grey relational analysis, BL and CH were the key morphometric traits influencing the body weight of E. modestus. These results provided references for candidate morphometric traits for E. modestus selective breeding programs.
The influence of different substrate culture environments on the intestinal microbial community of Babylonia areolata
Fang, Wei; Zhou, Cheng; Chen, Mingqiang; Zhao, Wang; Qin, Chuanxin; Yu, Gang; Ma, Zhenhua
This study aimed to evaluate how varying substrate culture environments influence the gut microbial community structure of Babylonia areolata. Three substrate culture environments were established using small ceramic grains (SC), silica sand (SS), and river sand (RS). High-throughput 16S rRNA sequencing was employed to characterize the gut microbial diversity and community structure of B. areolata across the three substrate environments. The results revealed a total of 9,975 OTUs, with 568 shared among all groups. Notably, the SC group exhibited 1,675 unique OTUs, exceeding those observed in the SS and RS groups; The SC group showed higher values for the richness, Simpson, Chao, and ACE indices compared to the SS and RS groups, suggesting that while the ceramic substrate promoted higher microbial abundance, it was associated with lower community diversity. However, these differences in diversity indices among the three groups were not statistically significant. Proteobacteria and Firmicutes overwhelmingly dominated the intestinal microbiota and represented the major phyla across all three substrate groups. At the genus level, the SC group was dominated by Mycoplasma, Psychrobacter, Shewanella, and Pseudoalteromonas. Vibrio, Pseudoalteromonas, and Mycoplasma predominantly inhabited the RS group. In the SS group, dominant genera included Pseudoalteromonas, Mycoplasma, Vibrio, and Burkholderia-Caballeronia-Paraburkholderia. Co-occurrence network analysis indicated that Mycoplasmataceae and Pseudoalteromonadaceae were the most strongly correlated taxa across all groups. These findings demonstrate that substrate composition significantly influences the gut microbial community structure and abundance in B. areolata, with ceramic substrates promoting increased microbial richness. This research provides foundational data and theoretical insights into sustainable aquaculture, disease management, and the development of functional feeds for B. areolata.
Research status, development mechanism and shortcomings of fishing port economic zones based on regional innovation system theory
Lyu, Chao; Li, Xiang; Zhu, Yong
To deeply explore the development mechanisms of Fishing Port Economic Zones (FPEZs), this study utilizes the Regional Innovation System (RIS) theory and constructs and applies a "Dynamics-Governance-Space" three-dimensional analytical framework. By systematically reviewing relevant domestic and international literature from 2014-2024, combined with keyword co-occurrence analysis and time-series data, the multi-dimensional characteristics and research status of FPEZ development are revealed. The results indicate that within the dynamics dimension, industrial upgrading and the integration of the three industries contribute to economic growth; however, they encounter challenges related to knowledge transfer and structural optimization. Policy coordination and institutional innovation strive to overcome path dependence in the governance dimension, with potential shown by diversified and digital governance. However, the deepening of mechanisms and the evaluation of effectiveness remain insufficient. Agglomeration-diffusion and network connectivity effects are emerging in the space dimension, but quantitative research on spatial heterogeneity and externalities is lacking. The study demonstrates that FPEZ development is a complex systemic process involving the dynamic coupling of dynamics, governance, and space. The proposed framework provides an effective tool for understanding this complexity. It also identifies shortcomings in current research regarding quantitative analysis, governance mechanisms, and innovation ecosystems. Future research should strengthen methodological innovation and expand research topics to support the high-quality sustainable development of FPEZs.
The impact of the aquaculture industry agglomeration on output growth in China
Wang, Jing; Sun, Chen; Wu, Yanfang; Jin, Hongtao
With the rapid development of China's aquaculture industry, the phenomenon of industrial agglomeration is becoming more and more obvious. This study uses the LMDI decomposition analysis method to empirically analyze the impact of aquaculture industry agglomeration on output growth. The study's conclusions include: (1) Aquaculture industry agglomeration plays an essential role in promoting the growth of aquaculture output. From 2006 to 2022, China's aquaculture production increased by 18.8711 million tons, and the agglomeration of the aquaculture industry promoted aquaculture production to increase by 5.162 million tons, with a contribution rate of 27.35 %. (2) The impact of China's aquaculture industry agglomeration on output growth shows different characteristics at different stages. During this period, the promotion effect of the agglomeration effect on output growth and the inhibition effect of the crowding effect on output growth are opposite. (3) Aquaculture industry agglomeration is a significant driving force for the output growth of different aquaculture models. The agglomeration of the aquaculture industry has promoted the growth of aquaculture output in deep-water cage, raft, bottom sowing aquaculture mode in mariculture, and pen, cage, and factory aquaculture mode in freshwater aquaculture. During this period, the agglomeration effect of the industrial agglomeration of the above aquaculture modes on the growth of the aquaculture output of each aquaculture mode is highlighted.
Comparative Analysis of Growth Traits, Textural Attributes, and Blood Biochemical Parameters in Procambarus clarkii under Varied Feeding Regimens
Ma, Guohong; Song, Liping; Zhang, Yanhua; Zheng, Xiaochuan; Mao, Shuquan; Wang, Bingli; Xu, Peng; Wu, Jun; Liu, Bo; Zhang, Wuxiao; Xia, Silei; Zhang, Yuanyuan
To systematically evaluate the trophic effects of Elodea nuttallii as exclusive versus complementary feedstock on growth performance, textural properties, and biochemical profiles in Procambarus clarkii, we conducted a controlled feeding trial employing four distinct nutritional regimes. The experiment followed a completely randomized design with four treatments (n=3 replicates/treatment; 20 crayfish/replicate). Dietary treatments included: a control group (0#) with access only to E. nuttallii and no supplemental feed, a soybean-supplemented group (1#) with E. nuttallii, a corn-supplemented group (2#) with E. nuttallii, and a formulated feed-supplemented group (3#) with E. nuttallii. Crayfish were fed twice daily (07:00 and 17:00) for 6 weeks. Results indicated that the control group (0#) showed significantly lower weight gain (WG) versus supplemented groups (P < 0.05) and the 3# experimental group showed the best growth. Among the four experimental groups, no significant differences were observed in hardness, brittleness, or elasticity of the muscle (P > 0.05). However, muscle cohesiveness peaked in the corn-supplemented group, differing significantly from other treatments (P < 0.05). In terms of gumminess, the 1# group demonstrated the highest value (8.50), which was significantly greater than that of the other groups (P < 0.05). Total protein (TP) reached maximum levels in the formulated feed group (3#), being significantly higher than in groups 0# and 2# (P < 0.05) but statistically equivalent to group 1# (P > 0.05). In contrast, the control group (0#) recorded the lowest TP content at 12.60. Regarding GLB (globulin) content, the 1#, 2#, and 3# groups demonstrated significantly higher values compared to the control group (P < 0.05). However, no significant differences in GLB content were observed among these three groups (P > 0.05). The results of this study suggest that P. clarkii exhibited optimal growth performance when reared with formulated feed supplemented with E. nuttallii. The soybean-E. nuttallii dietary combination yielded superior muscle nutritional quality and organoleptic characteristics. Plasma biochemical analyses confirmed the aquacultural advantages when Elodea-based systems were complemented with protein-rich feed supplementation, with the formulated feed regime showing particular promise.
Study on morphological characteristics and hypoxia tolerance of Culter alburnus (♀) × Magalobrama terminalis (♂) and Culter alburnus
Cheng, Shun; Zhang, Meifang; Jiang, Wenping; Chi, Meili; Zheng, Jianbo; Liu, Shili; Hang, Xiaoying; Peng, Miao; Li, Fei
C. alburnus (♀) × M. terminalis (♂) (CM) is a new national cultivar formed by interspecific hybridization between C. alburnus and M. terminalis. To explore the morphological characteristics and hypoxia tolerance of CM and C. alburnus, quantitative and countable traits were measured for CM and C. alburnus; then we conducted hypoxia stress research. The results: 1. The main characteristics of CM that differed from C. alburnus in appearance were an increase in body height and thickness, a small blunt pointed head, bulging back of the head, and large scales on the sides of the body. Among the countable traits, the numbers of lateral scales, upper lateral scales, and first-gill rakes of CM were significantly lower than those of C. alburnus, whereas the number of lower lateral scales was significantly greater than that of C. alburnus. 2. At the water temperature of 25 ℃, the DO value of C. alburnus was higher than that of CM. The Superoxide dismutase (SOD) or glutathione (GSH) index of CM increased more when it increased and decreased less when it decreased. The SOD or GSH index of CM was higher than that of the CM under the same hypoxic stress time. Therefore, it was speculated that CM might have stronger hypoxia tolerance than C. alburnus. In summary, CM was generally similar to C. alburnus in terms of morphological characteristics; however, there were differences in body height, body thickness, tail handle, and scales. It has been speculated that CM have a stronger tolerance to hypoxia.
Effects of Clostridium butyricum on Growth, Immunity, and Intestinal Microbiota of Penaeus monodon
Li, Jingyan; Zhou, Falin; Wen, Guoliang; Yang, Keng; Li, Yundong; Shi, Jianzhi; Ding, Yangyang; Zhang, Jianshe; Jiang, Song
This study aimed to investigate the effects of Clostridium butyricum and its metabolites on the growth, antioxidant capacity, and intestinal microbiota of a selected population of Penaeus monodon. A total of 360 shrimp with similar vitality and size, having an initial body mass of (2.33±0.05) g, were selected and randomly divided into four groups, with three replicates per group and 30 shrimp per replicate. The groups were designated as the control group (CG, no additive in feed), the yeast extract group (YYG, feed supplemented with C. butyricum yeast extract), the supernatant group (SQG, feed supplemented with the supernatant of C. butyricum), and the juice-sediment group (JNG, feed supplemented with the bottom sediment of C. butyricum). Following 31 days feeding trial, the results showed that compared with the CG, the weight gain (WG), survival rate (SR), and specific growth rate (SGR) of YYG, SQG, and JNG increased, with YYG being significantly higher than CG (P\<0.05), while JNG and SQG did not show significant differences compared to CG (P\>0.05). Protease and lipase activities were significantly enhanced in YYG (P\<0.05), alkaline phosphatase (AKP) activity was significantly higher in YYG and JNG than in CG (P\<0.05), while there was no significant difference between SQG and CG (P\>0.05). Acid phosphatase (ACP) activity was significantly higher in YYG and SQG compared to CG (P\<0.05), with no significant difference between JNG and CG (P\>0.05). Intestinal microbiota sequencing revealed that Proteobacteria was the most abundant phylum in all experimental groups, accounting for 71%, 69%, 73%, and 75% respectively. At the gene expression level, compared with CG, YYG showed significantly higher relative expression levels of immune-related genes such as PO, Toll, IMD, and Relish, as well as antioxidant-related genes such as CAT, GSH, and hsp70 in the hepatopancreas of P. monodon (P\<0.05). Under the conditions of this experiment, supplementing feed with C. butyricum yeast extract achieved the best probiotic effect in P. monodon farming.

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