Table of Content

25 August 2024, Volume 46 Issue 4

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Research Paper

Effects of dietary lipid levels on growth performance, body composition, biochemical indices and liver enzyme activities of juvenile Epinephelus fuscoguttatus ♀ × E. polyphekadion ♂

XIE Ruitao, LIU Min, WANG Zhuoduo, HUANG Jiansheng, CHEN Gang, WU Xugan, ZHANG Haitao

2024, 46(4):  311-321.  DOI: 10.14012/j.jfr.2024004

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Objective: The study aimed to investigate the impact of dietary lipid levels on the growth performance, body composition, and biochemical indices of juvenile Epinephelus fuscoguttatus ♀ × E. polyphekadion ♂ hybrid (approximately 7.16 g). Methods: An 8-week feeding trial was conducted, during which five isonitrogenous experimental diets containing 5.86%, 7.74%, 9.72%, 11.74%, and 13.68% dietary lipid (referred to as L1, L2, L3, L4, and L5, respectively) were formulated using fish oil as the primary lipid source. Results: 1) The optimal growth performance of juvenile E. fuscoguttatus ♀ × E. polyphekadion ♂ was observed at a dietary lipid level of 9.72%?11.74%. At this level, weight gain rate (WGR) and condition factor (CF) significantly increased (P<0.05), while feed conversion ratio (FCR) decreased significantly (P<0.05). 2) Dietary lipid levels did not significantly affect whole body and muscle moisture content (P>0.05). However, increasing dietary lipid levels led to a gradual increase in crude lipid content in both whole body and muscle, accompanied by a decrease in crude protein content in the whole body. 3) As dietary lipid levels increased, the levels of serum total protein (TP), albumin (ALB), and low-density lipoprotein (LDL) decreased, while serum glucose (GLU), triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activities increased. 4) Liver superoxide dismutase (SOD), catalase (CAT), and lysozyme (LZM) activities increased gradually with increasing dietary lipid levels up to 9.72%. However, CAT levels decreased when dietary lipid levels exceeded 9.72%, and SOD levels decreased when dietary lipid levels exceeded 11.74%. 5) Second-order polynomial regression analysis of WGR and FCR indicated that the optimal dietary lipid level for juvenile E. fuscoguttatus ♀ × E. polyphekadion ♂ were 9.77% and 10.39%, respectively. Conclusion: Under the conditions of this practical test, the recommended amount of fat in the diet of juvenile E. fuscoguttatus ♀ × E. polyphekadion ♂ was 9.77% ? 10.39%. Significance: These results will be beneficial for the development of precise and efficient compound feed for juvenile E. fuscoguttatus ♀ × E. polyphekadion ♂.

Preliminary study on inducing sex reversal in mature female large yellow croaker (Larimichthys crocea)

ZHANG Jiarui, CUI Yu, HU Guoliang, ZHANG Lining, REN Peng, WANG Zhiyong

2024, 46(4):  322-330.  DOI: 10.14012/j.jfr.2024030

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Objective: The growth rate of female large yellow croaker (Larimichthys crocea) is significantly faster than that of males, making all-female fry highly desirable to aquaculturists. A common method to produce all-female fry involves treating genetically female fish (XX) with androgens before gonadal differentiation to develop them into physiological males (neomale, XX ♂), and then crossing them with original females (XX ♀). However, this method is time-consuming and androgen treatment (using methyltestosterone, MT) severely inhibits the growth of L. crocea fry. Directly inducing sex reversal in adult female L. crocea to become physiological males could circumvent these issues. This study aims to explore the possibility and methods of inducing sex reversal in sexually mature female L. crocea to cultivate physiological males, providing an efficient new approach to produce physiological male fish. Methods: A combination of MT and PHTPP was used as an inducing agent. The mixed drug was made into chitosan gel strips or dissolved in soybean oil to create a sustained-release solution. The mixture was injected into the abdominal cavity of mature female L. crocea to induce the sex reversal of the fish. The histological changes in the gonads were observed, and changes in serum sex hormone levels and the expression of estrogen receptor gene in the gonads were measured. Results: The results showed that the MT-PHTPP-soybean oil mixture had a better inducing effect than the chitosan-MT-PHTPP gel strips. Injecting a dose of (40 μg MT + 4 μg PHTPP) per kg of fish body mass of the MT-PHTPP-soybean oil mixture into the abdominal cavity and continuing treatment for 80 days resulted in ovarian degeneration in the experimental group. Morphologically, the ovaries exhibited changes resembling testes. A large number of spermatogonia were formed, serum estradiol levels significantly decreased, and 11-ketotestosterone levels significantly increased (P<0.05). The expression of the estrogen receptor Esr2 gene in the gonads was severely inhibited. Conclusion: The experimental results indicate that it is possible to cultivate physiological male L. crocea by inducing sex reversal in sexually mature females through gonadal differentiation and development.

Effect of different air exposure time on non-specific immune function of Paphia undulata

LIU Yunguang, CHEN Zhi, JIANG Yixiong, ZHONG Guolong, LIN Gang, LIN Weilang

2024, 46(4):  331-337.  DOI: 10.14012/j.jfr.2024007

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Background: Papia undulata is a famous economic shellfish in the South China Sea, mainly distributed in the coastal areas of Fujian, Guangdong, Guangxi and other provinces. Dry transport is the main method of the transportation of P. undulata. Long-term air exposure will affect the flavor of P. undulata and even lead to its death. Objective: To investigate the effects of different air exposure time on immune related indices of P. undulata, a marine shellfish. Methods: P. undulata was exposed to air for 0 h (control group), 6 h, 12 h and 24 h, respectively, and seawater culture was resumed after air exposure and the time nodes of seawater culture for 2, 6, 12 and 24 h, respectively, were restored. The indices of acid phosphatase (ACP), alkaline phosphatase (AKP), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and nitric oxide (NO) were determined after homogenization of the axilla unguiculata foot tissue at low temperature. [Results] Air exposure time within 24 h had no significant effect on the activities of hydrolase (ACP and AKP) (P>0.05), but had significant effects on the activities of antioxidant enzymes (SOD and CAT) and the content of oxygen free radicals (MDA and NO). Air exposure had a certain inhibitory effect on the activity of antioxidant enzymes, and the longer the air exposure time, the greater the fluctuation of SOD and CAT activities, and the more serious the oxidative damage. The longer the air exposure time, the higher the MDA content, the more serious the damage of P. undulata membrane, and the trend of NO content first increased and then decreased, which may be related to the protective effect of a large amount of NO produced by short time air exposure on the body. Conclusion: The results indicate that the axe-foot tissue is not the main metabolic site of P. undulata, but the key site of antioxidant processes. The longer the air exposure time within 24 h, the greater the influence of antioxidant enzyme (SOD, CAT) activity and oxygen free radical (MDA, NO) content related immune indices, but had no significant effect on hydrolase (ACP, AKP) activity, indicating that the axe-foot tissue is the key site of antioxidant process in the body of P. undulata. Significance: The results of this study provide reference for the screening of immune physiological indices and physiological response mechanism of P. undulata under air exposure stress, and provide basic data for the preservation of P. undulata during long-distance transportation.

Analysis of copper and zinc tolerance in the different metal accumulation ability strains of Crassostrea angulata

GUO Anqi, KE Caihuan, WANG Tian, SHI Bo

2024, 46(4):  338-346.  DOI: 10.14012/j.jfr.2024049

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Background: Oysters possess formidable metal accumulation capabilities, earning them the title of hyperaccumulators of copper and zinc. Furthermore, they can survive normally even after accumulating significant amounts of these metals, demonstrating exceptional metal tolerance. Individual differences in oyster metal accumulation abilities are notably significant, representing a quantitative trait. Studies including enrichment kinetics and whole-genome association analyses have elucidated mechanisms underlying differences in oyster metal accumulation capabilities. However, whether these differences in accumulation capabilities affect metal tolerance remains inconclusive. Objective: Investigating the differences in copper and zinc tolerance among oysters with varying metal accumulation capacities at different developmental stages. Methods: This study utilized high copper-zinc accumulating strains and low copper-zinc accumulating strains of Fujian oysters (Crassostrea angulata) to conduct experiments. Metal contents in parental C. angulata of different strains were measured, and acute toxicity tests for copper and zinc were performed on D-shaped larvae and 6-month-old adults of both strains, calculating the median lethal concentration (LC₅₀). Results: There were significant differences in copper and zinc contents between parental C. angulata of the two strains. During the D-shaped larval stage, the 24-hour zinc LC₅₀ of larvae from the low accumulation strain was significantly lower than that of larvae from the high accumulation strain, while the 24-hour copper LC₅₀ showed no significant difference between the two strains. Thus, the high accumulation strain exhibited significantly greater tolerance to zinc than the low accumulation strain, but both strains showed no significant difference in copper tolerance. In the adult stage, the copper and zinc LC₅₀ values at 96 hours for adults of the high accumulation strain were higher than those of the low accumulation strain, indicating significantly greater tolerance to copper and zinc in the high accumulation strain compared to the low accumulation strain. Conclusion: This study lays the groundwork for exploring the relationship between oyster metal accumulation capability and its tolerance, further providing insights into oyster metal accumulation and detoxification mechanisms. Additionally, research on oyster metal accumulation and tolerance phenomena is crucial for ensuring food safety and utilizing oysters as indicators for environmental monitoring.

Analysis of effects of morphological traits on body mass and curve fitting of adult red swamp crawfish (Procambarus clarkii) from Yutai area, Shandong Province

JIANG Yan, CAO Zhenjie, HE Fei, YAN Fajun, ZANG Jinliang, WU Jun, WANG Bingli, XU Haiqiang

2024, 46(4):  347-359.  DOI: 10.14012/j.jfr.2024016

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Objective: To investigate the correlation between morphological characteristics and body mass of red swamp crawfish (Procambarus clarkii) in the Yutai area of Shandong Province. Methods: Through correlation analysis, path analysis, and decisive analysis. The study measured the body mass and 12 morphological traits of 195 tail P. clarkii (weighing≥15 g), and examined the impact of morphological traits on body mass. Additionally, the study established a regression equation for body mass using stepwise regression and constructed fit curves for individual traits and body mass. Results: The results revealed that the coefficient of variation of body mass was highest across all populations, indicating that body mass had a greater selection potential compared to other traits. Moreover, morphological traits were significantly correlated with body mass in mature individuals (P<0.05 or P<0.01). Path analysis and decisive analysis further identified key traits influencing body mass within different populations. For females, total length, head breastplate width, pincers width, and telson length were primary factors, while for males, pincers width, head breastplate length, and head breastplate width were significant. In mixed populations, total length, pincers width, and head breastplate width played major roles. Regression equations for females, males, and mixed populations, with morphological traits as independent variables and body mass as the dependent variable, were derived as follows. Female population: y_female=?29.103+0.169X₂+1.018X₇+0.694X₅+0.561X₁₀ (R²=0.856); male population: y_male=?38.973+1.243X₅+0.209X₆+1.882X₇ (R²=0.918); mixed populations: y_mixed=?48.475+0.395X₂+1.368X₅+0.97X₇ (R²=0.932). The fit curve models for the main morphological traits and body mass of P. clarkii in Yutai area were mainly binomial models, otherwaise the fit curve model for head breastplate width and body mass in mixed populations was power function model, the fit curve model for pincers width and body mass in female population was the exponential function model. Curve model types in different populations were also different. Conclusion: In the breeding of P. clarkii in Yutai area, head breastplate width should be considered firstly, while pincers width and head breastplate length should be as assistant traits in the selection in male population. Head breastplate width should be considered firstly, while pincers width, total length and telson width should be as assistant traits in the selection in female population. Pincers width should be considered firstly, while total length and head breastplate width should be as assistant traits in the selection in mixed populations. Fit curve models predominantly followed binomial patterns for main morphological traits and body mass of P. clarkii in Yutai area. Significance: The results of this study may provide reference for the genetic breeding of P. clarkii.

Effects of species of algae to feed and stocking density on growth and development of blood clam Scapharca subcrenata larvae

HAO Yongfang, LÜ Xiaomin, CAO Chen, GAO Chao

2024, 46(4):  360-366.  DOI: 10.14012/j.jfr.2024014

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Background: With the shellfish aquaculture industry developing and wild resources declining, the demand for blood clam (Scapharca subcrenata) seedlings is increasing. However, in northern China, the seed breeding technology for this species remains unstable. Enhancing larval survival and metamorphosis rates, reducing growth duration, and producing high-quality, fast-growing seeds are crucial for successful seedling cultivation in this region. Algae species and stocking density significantly influence the breeding process and are more manageable compared to other environmental factors. This study aims to explore the impacts of algae species and stocking density on the growth and development of blood clam larvae in northern China, where such research is currently lacking. Methods: Single factor analysis of variance (ANOVA) and multiple comparison analysis (Duncan) were employed for data analysis in this study. The study investigated the effects of algae species and stocking density on the growth and development of blood clam larvae under controlled conditions of 24.2?27.5°C water temperature, salinity of 26?27, and pH ranging from 8.2 to 8.5. Six algae groups were tested: Isochrysis zhanjiangensis, Chaetoceros mulleri, Chlorella saccharophila, combinations of I. zhanjiangensis with C. mulleri and C. mulleri with C. saccharophila, and a mix of I. zhanjiangensis, C. mulleri, and C. saccharophila. Stocking density was varied across five levels: 2, 5, 10, 15, and 20 ind/mL. Results: The results indicated that larvae fed solely with C. mulleri exhibited superior growth and development, while those fed with C. saccharophila showed the poorest performance. Mixed feeding regimes outperformed single algae diets, with larvae fed a combination of I. zhanjiangensis, C. mulleri, and C. saccharophila demonstrating the highest growth, survival, and metamorphosis rates. Additionally, increasing stocking density correlated with decreased larval growth, survival, and metamorphosis rates, with marginal differences observed between the 5 ind/mL and 10 ind/mL groups during the creeping stage. Conclusion: In the artificial cultivation of blood clam, it is recommended to avoid relying on C. saccharophila as the primary algae source, favoring single feeding of C. mulleri instead. Optimal juvenile yields were achieved by feeding a mixed algae diet containing C. mulleri, particularly at a stocking density of 10 ind/mL during the floating stage and between 5 to 10 ind/mL during the postlarval stage. Significance: This study provides robust theoretical support and significant guidance for the seed breeding of blood clam under ambient temperatures in northern China. The findings are poised to advance the blood clam aquaculture industry.

Comparison of basic RPA and RPA-LFD assays for Anguillid herpesvirus

LIN Ershu

2024, 46(4):  367-374.  DOI: 10.14012/j.jfr.2024012

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Objective: Eel is a major freshwater aquaculture economic species in China. Eel is rich in nutrients and delicious meat, which is very popular among consumers. However, with the continuous development of intensive aquaculture mode, there are more and more kinds of diseases in eel culture, among which the danger of viral diseases is particularly serious. Anguillid herpesvirus (AngHV) poses a significant threat to eel (Anguilla) breeding, often resulting in economic losses. Developing rapid detection technologies for AngHV is crucial for disease prevention and control in China’s eel industry. Methods: AngHV DNA was extracted from liver and gill tissues of diseased eels in the laboratory using a DNA extraction kit. This study designed amplification primers and probes targeting AngHV ORF55 to establish basic RPA and RPA coupled with lateral flow detection (RPA-LFD) methods. The effects of time and temperature variations on RPA and RPA-LFD amplification were investigated. The sensitivity, specificity, and clinical applicability of both methods were compared. Results: Both basic RPA and RPA-LFD assays amplified products of 394 bp within 20 to 40 minutes.The basic RPA assay time exceeded 80 min, which easily led to the appearance of stray bands. When the RPA-LFD detection time was extended to 160 min, the negative control group was prone to false positives. Temperature variations between 37 °C to 43 °C minimally affected amplification efficiency. It indicated that the change in temperature has little effect on the amplification results. Specificity tests showed no cross-reactivity with Eel circovirus, Cyprinid herpesvirus, and Koi herpesvirus. RPA-LFD exhibited high sensitivity with a detection limit of 1.32×10⁰ copies/mL, while basic RPA had a limit of 1.32×10³ copies/mL. Testing 20 clinical eel samples yielded consistent results between the two assays, with a 30% positive detection rate, indicating promising clinical applicability for both methods. Conclusion: In this study, the primers of basic RPA and RPA-LFD were designed in the conserved region of AngHV genes, and the reaction time and temperature were optimised, and finally the rapid detection methods of basic RPA and RPA-LFD for AngHV were established. Both methods have the advantages of rapidity, sensitivity, specificity and good clinical application. The basic RPA and RPA-LFD assays for AngHV detection are suitable for use in grassroots research institutes, eel product processing farms, and breeding facilities. These methods expand the toolkit for detecting eel herpesvirus, enhancing disease management in the eel industry.

The diversity and community structure of nekton in the estuary of Xiamen Bay, Fujian Province in summer

MA Chao, ZHUANG Zhidong, LIU Yong, XU Chunyan, ZHU Jianxin, WU Tongjin, YU Wei, XIE Shaoqing, SHEN Changchun, CAI Jiandi

2024, 46(4):  375-383.  DOI: 10.14012/j.jfr.2024023

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Objective: Xiamen Bay is located in the southeast of Fujian Province. It is rich in nutrients and has a strong biological basis. It is an important place for spawning, breeding, feeding and inhabiting of various fishery resources. In order to study the diversity and community structure of nekton in Xiamen Bay estuary. Methods: Based on the data of bottom trawl survey of fishery resources in Xiamen Bay estuary in August 2023, the study used the methods of relative importance index, resource density index, biodiversity index and cluster to conduct research. The study analyzed the species composition, dominant species, resource density, species diversity and community structure characteristics of nekton. Results: Results revealed a total of 147 nekton species captured during the survey period, spanning 107 genera within 63 families across 19 orders. Among these, there were 92 species of fish, 8 species of cephalopods, 8 species of stomatopods, 13 species of shrimps and 26 species of crabs. The average weight density and quantity density of nekton were 450.58 kg/km² and 4.42×10⁴ ind/km². Dominant species included Parapenaeopsis hardwickii, Parapenaeopsis cultrirostris, Oratosquilla oratoria, and Metapenaeopsis barbata.The Margalef richness index D ranged from 5.68 to 10.23, indicating moderate species richness. Shannon-Wiener diversity index H'_N and Pielou evenness index J'_N, based on individual number, varied between 1.47?3.34 and 0.38?0.88, respectively. Similarly, Shannon-Wiener diversity index H'_W and Pielou evenness index J'_W, based on biomass, ranged from 2.09 to 3.41 and 0.54 to 0.87, respectively. Hierarchical clustering and non-metric multi-dimensional scaling analysis delineated two distinct station groups within the estuary of Xiamen Bay: northern and southern. The results of NMDS sorting and CLUSTER hierarchical clustering analysis were relatively consistent. P. hardwickii and P. cultrirostris emerged as the primary dissimilar contributing species to these groups. Conclusion: The number of species in this survey is more than that in Xiamen Bay and Jiulong River estuary in recent years, and the dominant species were small, low trophic level and short life cycle species. These indices collectively indicated an overall moderate to high diversity level. The average species diversity index indicated an overall moderate diversity level. Catch miniaturisation is evident. Affected by the decline of fish resources, shrimp resources with short life cycle and strong fecundity have become an important supplement to fishery resources. Significance: This study supplements the basic data of nekton community in Xiamen Bay, and provides a scientific basis for the protection and management of ecosystem diversity in this sea area.

The practice of the total allowable catch system in South Korea and its enlightenment to China

XU Jingjing, LI Weipeng, MA Yujie, WU Qiong, MA Delin

2024, 46(4):  384-392.  DOI: 10.14012/j.jfr.2024026

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Objective: This study aims to explore the direction of total allowable catch (TAC) management in China, enhance the effectiveness of China’s TAC system and realize the sustainable development of China’s marine fisheries by drawing lessons from South Korea’s experience and practices. [Progress] The initial stage of China’s TAC management faces challenges such as overly high quotas and inadequate regulatory oversight. To address these issues, this paper conducts a comparative analysis with South Korea, a country with a similar fishery context. It expounds the necessity of implementing the TAC system in China under the current situation, examines the implementation status of TAC systems in both countries, and delves into the development histories, implementation processes, and identifies key experiences and shortcomings of South Korea’s TAC system. Conclusion: Drawing on insights and lessons from South Korea, this study proposes recommendations for enhancing TAC management in China to effectively solve the existing problems in the initial stage of TAC in China, and avoid new problems caused by system loopholes. Suggestions include establishing a comprehensive legal and regulatory framework for TAC, implementing long-term fishery resource monitoring, instituting rigorous TAC monitoring mechanisms, and enhancing public awareness, education, and training on TAC systems. These measures aim to facilitate the effective implementation of TAC in China and foster high-quality development in the fisheries sector.

Review

Development status and prospect of gravity deep water cage in China

XUE Zun, SHI Jiangao, ZHANG Wenyang

2024, 46(4):  393-402.  DOI: 10.14012/j.jfr.2024011

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Background: Due to the depletion of global marine fishery resources and the increasing pressure of fishing, traditional cage culture is limited by space and cannot meet the urgent needs of human beings for seafood. Gravity deep water cage culture can make better use of marine fishery resources, which is one of the important ways to solve this problem. Progress: Therefore, this paper analyzes the development of gravity deep-water cage in China, describes the research direction and application of gravity deep-water cage, and prospects its future. So far, China’s gravity deep-water cage technology has made great progress, and some achievements such as rope mesh materials, aquaculture supporting equipment and aquaculture technology have been industrialized. [Outlook] At the same time, China’s gravity deep water cages need to continue to innovate and improve in terms of cage structure and materials, intelligent management and green aquaculture technology, in order to promote the high-quality development of deep water cages. Significance: The development of China’s gravity deep-water cage not only helps to alleviate the pressure of offshore cage farming, but also promotes the transformation and upgrading of China’s marine cage farming industry, and contributes to the prosperity of China’s aquaculture industry and the protection of the marine ecological environment.

Research progress of tetrodotoxin-producing microorganisms

YANG Zihan, CAI Shuilin, XU Min, QIAO Kun, CHEN Bei, TIAN Mengmeng, HUANG Wenshu, LIU Zhiyu

2024, 46(4):  403-412.  DOI: 10.14012/j.jfr.2024019

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Background: Tetrodotoxin (TTX) is recognized as one of the most potent marine toxins, extensively found in marine organisms like pufferfish. Functioning as a potent sodium channel blocker, TTX has demonstrated considerable potential in medical applications such as pain relief, detoxification, and antiarrhythmic therapy. Despite these benefits, its current medical use is constrained by challenges in sourcing and low yield. Consequently, there is burgeoning interest in exploring microbial fermentation as a promising avenue for TTX production. Objective: The aim of the present study is to get to know the overview of TTX, the distribution and taxonomic diversity of TTX-producing microorganisms, research on TTX fermentation production technology, and the migration mechanism of TTX in microorganisms and the environment. [Progress] Currently, there is a comprehensive understanding of the physicochemical properties of TTX within the academic community, although its precise natural sources remain ambiguous. Since 1986, researchers have isolated around 150 strains of TTX-producing bacteria from organisms such as pufferfish and blue-ringed octopuses, primarily belonging to Vibrio and Bacillus species. These findings not only strongly support the microbial origin of TTX but also establish a robust foundation for further research into microbial fermentation for TTX production. Numerous scholars have conducted extensive studies on the pivotal factors influencing TTX production by these strains, as well as their migration mechanisms, yielding significant findings. [Prospects] Future research could focus on targeted modification of TTX-producing strains, improvement of large-scale cultivation conditions, exploration of key factors influencing TTX production by these strains, and analysis of microbial community interactions affecting TTX synthesis. These efforts would provide valuable insights into elucidating the biosynthetic mechanism of TTX. [Significance] Through in-depth research on TTX-producing microorganisms, the article aims to elucidate the biosynthetic pathway of TTX, enabling large-scale production. This could address the challenges of sourcing and high costs, thereby expanding the potential applications of TTX in the medical field.

Progress in algal bloom management by algal lytic bacteria

YANG Yan, SUN Kunkun, XIE Yanping, MA Yantian, ZHANG He

2024, 46(4):  413-424.  DOI: 10.14012/j.jfr.2023127

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Background: In recent years, the escalation of global warming and the exacerbation of eutrophication in aquatic environments have precipitated a widespread predicament: algal blooms instigated by the rampant proliferation of algae. This phenomenon transcends localities, evolving into a formidable global issue with profound ramifications for ecosystems and public welfare. Progress: Algicidal bacteria, emerging as potent biological agents for mitigating detrimental algal overgrowth, have emerged as focal points within scholarly discourse. Notably, substantial strides have been made in unraveling the algicidal mechanisms, both in theoretical inquiry and practical implementation. This paper presents a comprehensive overview of the contemporary advancements in algicidal bacteria research, encompassing the spectrum of strain diversity, algicidal mechanisms, activity characteristics, and the bioactive compounds they generate, alongside the deployment of algicidal bacterial agents. Special emphasis is placed on elucidating the tripartite algicidal modalities, including indirect, direct, and synergistic approaches, which adopted by these bacteria, and scrutinizing the varied impacts of algicidal substances on algal proliferation. Lastly, this paper delineates future research prospects, advocating for deeper exploration into the molecular underpinnings of algicidal bacteria and intensified studies on algicidal compounds’ isolation. Significance: By shedding light on prospective research trajectories, this endeavor aims to enrich our comprehension of algicidal mechanisms, furnishing a theoretical scaffold for algal bloom mitigation and the preservation of aquatic ecosystem vitality.