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Understanding the diversity and function of fish gut microbiomes has advanced substantially, yet many aspects remain poorly understood, particularly the interplay among microbiota, host species, and environmental factors in the context of conservation. This review explores the composition and abundance of gut bacterial communities in key aquaculture fish groups—cyprinids, ictalurids (catfish), salmonids, and cichlids (tilapia)—alongside the model organism zebrafish, across diverse geographic regions. The findings highlight environmental habitats and host species as primary determinants of gut microbiome structure, offering a global perspective on these microbial communities. Across all fish groups, the phyla Firmicutes, Fusobacteria, and Proteobacteria consistently dominated, while temperate, sub-equatorial, and sub-tropical regions exhibited the highest microbiome diversity, underscoring the contribution of taxonomic and environmental factors. The gut bacterial diversity of farm-raised fish shows a significant divergence from that of wild-caught fish, reflecting the impacts of ecological and management differences. Understanding the dynamic responses of fish gut microbiota is vital for guiding conservation efforts, safeguarding aquatic biodiversity, and advancing sustainable aquaculture practices. Future research should leverage innovative techniques and integrative approaches, both experimental and theoretical, to uncover the functional roles of microbiomes and predict their responses to environmental changes. Expanding geographic and taxonomic coverage will be critical for creating a comprehensive framework to inform global aquaculture and conservation strategies. Collectively, this perspective highlights the transformative potential of microbiome research in addressing global challenges in aquaculture and conservation biology. [ABSTRACT FROM AUTHOR]

Natural and anthropogenic causes have led to soil degradation, salinisation of inland areas, and groundwater. The degraded soils are unsuitable for primary agriculture, but can be utilised for saline aquaculture. ICAR-CIFE has initiated a selective breeding program for faster growth in common carp cultured at low salinity (6–8 ppt). The present study demonstrates the dynamic nature of physico-chemical parameters of Inland Saline Ground Water (ISGW) and the growth potential of selectively bred F1 generation of common carp using ISGW. About 1560 common carp fingerlings were stocked in two ponds, each representing a unique size class (> 100 g and < 100 g). "The water quality parameters, viz., temperature, salinity, pH, dissolved oxygen, total hardness, total alkalinity, calcium, and magnesium recorded during the culture period had mean values of 30.27 ℃, 6.73 ppt, 8.48, 5.02 mg L−1, 1544.83 mg L−1, 217.29 mg L−1, 177.22 mg L−1 and 332.33 mg L−1, respectively". The average body weight of common carp at stocking in Pond 1 and Pond 2 was 42.43 g and 180.86 g, respectively. The average standard length at stocking for Pond 1 and Pond 2 was 10.57 cm and 16.57 cm, respectively. The overall means for harvest body weight and standard length at 200 days of culture in summer months were 432.48 ± 4.14 g and 22.72 ± 3.04 cm, respectively. The effects of standard length, sex of fish, and sex by pond interaction were found to be significant on the harvest body weight. The Feed Conversion Ratio (FCR), Feed Conversion Efficiency (FCE), and Protein Efficiency Ratio (PER) obtained for Pond 1 and Pond 2 were 2.19, 45.8, 1.53; 2.25, 44.44, and 1.48, respectively. The daily weight gain for Pond 1 and Pond 2 was 1.58 g and 1.61 g, respectively. In conclusion, the common carp reared in an inland saline environment showed a similar growth pattern in both size classes as reported in freshwater culture. Thus, the present study recommends common carp as a potential candidate species for inland saline aquaculture in degraded soils and advocates its scientific propagation. Article Highlights: The study demonstrates the summer growth performance of common carp fingerlings stocked in two ponds, each representing a unique size class (> 100 g and < 100 g) The average culture temperature and salinity were 30.27 ℃ and 6.73 ppt The mean harvest body weight and standard length at 200 days of culture were 432.48 ± 4.14 g and 22.72 ± 3.04 cm, respectively The daily weight gain for Pond 1 and Pond 2 was 1.58 g and 1.61 g, respectively. [ABSTRACT FROM AUTHOR]

Introduction: This study evaluates the feasibility of culturing the high-value marine fish Protonibea diacanthus in a polyculture system with Indian pompano (Trachinotus mookalee) using a marine cage culture setup. The study aims to determine growth performance, feed efficiency, and the potential of P. diacanthus as a candidate species for polyculture. Methods: Wild-caught P. diacanthus were reared in six high-density polyethylene sea cages (Inner Diameter: 6 m; Outer Diameter: 7 m; Depth: 4.5 m; Area: 28.29 m²; Volume: 127.29 m³). Two experimental groups were established: Group-1 with 90 individuals (average weight: 130.15 ± 6.39 g) and Group-2 with 90 individuals (average weight: 287.80 ± 16.90 g). Each group was divided into three cages (30 fish/cage) and reared in triplicate with T. mookalee (2,500 fish/cage, average weight: 31.12 ± 1.17 g). The fish were cultured for 148 days and fed a commercial diet (40% crude protein, 10% crude lipid). Growth indices and feed efficiency indices were analyzed, and growth of the fish was modeled using von Bertalanffy Growth Function (VBGF). Results: Growth performance indices, including total length gain, body weight gain, and specific growth rate, were significantly higher in Group-1 (P ≤ 0.05). Feed efficiency indices (feed conversion ratio, feed efficiency ratio, and protein efficiency ratio) did not differ significantly between the groups (P > 0.05). VBGF modeling estimated P. diacanthus asymptotic length (L∞) at 164.21 ± 3.58 cm, asymptotic weight (W∞) at 44,070.19 ± 2811 g, growth coefficient (K) at 0.30 ± 0.01 yr−1 and t₀ at -0.005 ± 0.02 yr. The growth performance index (ϕ') was calculated at 1.91, surpassing values reported for wild populations. Polyculture with P. diacanthus did not significantly affect the growth or feed utilization of T. mookalee (P > 0.05). Discussion and conclusion: The results indicate that P. diacanthus exhibits superior growth under marine cage culture conditions, with a high growth performance and compatibility in polyculture systems. These findings support the potential of P. diacanthus as a viable candidate for integration into commercial polyculture systems. [ABSTRACT FROM AUTHOR]

The freshwater prawns of the genus Macrobrachium Spence Bate, 1868, hold major potential for sustainable aquaculture intensification and diversification. Beyond the dominant giant river prawn M. rosenbergii (De Man, 1879), successful larviculture and domestication of additional species could boost production. However, inconsistent hatchery results have hampered the wider application and commercialization of cultivation protocols. This comprehensive review aims to analyse past larviculture research efforts to advance Macrobrachium farming practices. Several published studies documenting larviculture experiments on various Macrobrachium taxa are examined. Larval developmental patterns, optimal rearing salinity and temperature ranges, stocking densities, feeding regimes, and reported survival rates are compared within and among species. Significant inter- and intraspecific variability is apparent, highlighting the need for species-specific approaches. Past studies have applied generalized techniques derived from M. rosenbergii with varying success, further motivating the analytical review of findings. Key bottlenecks impeding consistent hatchery seed production are identified. In particular, knowledge gaps regarding larval nutritional needs, biofouling prevention, and weaning method optimization present ongoing challenges. By reconciling contradictory results and emphasizing biological nuances, this review distinguishes priorities for strengthening protocol development. Priorities include standardizing assessments, disseminating optimized techniques tailored to particular target species, and outlining future research directions. With reliable hatchery production, additional Macrobrachium species could be incorporated into polyculture or mono-crop systems, supporting livelihood diversification and sustainable intensification of aquaculture. [ABSTRACT FROM AUTHOR]

Aquaculture has proven to be a vital and very efficient source of animal protein to meet the food demands of the ongoing increase in the global human population. In response to the rising accumulation of atmospheric greenhouse gases (GHG), principally of anthropomorphic origin from use of fossil fuel energy sources, global oceanic and atmospheric temperatures have risen to cataclysmic levels that have produced dramatic changes in climate. Aquaculture, like all animal production systems is a contributor to global GHG, and strategies must be introduced to mitigate current and future threats of climatic disruptions. Important pathways to reduce carbon footprint contributions include increases in efficiency of production and appropriate choice of ingredients for manufacture of sustainable aquafeed. For fed production systems, use of feed grade rather than food grade sources of ingredients must typically predominate. Additionally, use of waste consistent with circular bioeconomy concepts and the guidance provided through results of life cycle assessment (LCA) must be applied to aquafeed production. An integral connection of these efforts with a timely transformation from use of fossil fuel to renewable sources of energy is essential. Achieving sufficient reductions in both aquaculture's carbon footprint and fossil fuel use within the next 25 years should determine whether the projected contribution of aquaculture to global food security is realized. [ABSTRACT FROM AUTHOR]

With the expanding global population, interest has increased in the sustainable aquaculture development of indigenous fishes. In Hawaiʻi, the brassy chub, Kyphosus vaigiensis, has drawn interest as a candidate species for production. However, little is known about its resilience in aquaculture settings where fish are exposed to acute, husbandry‐related stressors. To address the response of brassy chub to handling stress, we characterized the effects of simulated netting and confinement stress on physiological parameters indicative of the alarm and resistance phases of the stress response over a 24‐h time course. Specifically, we measured plasma osmolality and glucose, mucous cortisol, hepatic activity of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPX), and hepatic lipid peroxidation (LPO). Plasma osmolality in stressed fish was increased relative to controls at 1 and 6 h. Mucous cortisol levels were transiently increased in stressed fish at 1 h following handling stress. In stressed fish, plasma glucose was generally increased from 1 h to 24 h relative to controls. By contrast, SOD activity decreased in stressed fish at 6 and 12 h, returning to control levels at 24 h; GPX activity and LPO were unaffected by the handling stressor. The transient and modest responses of mucous cortisol and antioxidant enzyme activity indicate the recovery of brassy chub from handling stress. Moreover, the sustained increase in plasma glucose and lack of change in LPO suggest mobilization of energy and long‐term resiliency toward handling stressors. [ABSTRACT FROM AUTHOR]

Vaccination is the most effective measure to prevent disease outbreaks in fish aquaculture, with oral vaccine administration emerging as the most practical approach. However, oral vaccines face a notable limitation due to insufficient stimulation of the complex gut-associated lymphoid tissue caused by factors such as vaccine degradation, poor absorption, and recognition by the immune cells. An innovative solution to these limitations lies in the plant-based production of recombinant vaccines. Plant cells enable the production and targeted storage of recombinant vaccines in specific cell organelles which ensure superior protection from degradation and contain natural compounds acting as adjuvants. Our study explores the potential of barley (Hordeum vulgare), a globally significant cereal crop, for producing orally administered subunit vaccines against viral infections affecting economically important fish species in the Salmonidae and Cyprinidae families. Through Agrobacterium-mediated transformation of immature barley embryos, we have generated homozygous T 2 generation of transgenic barley expressing recombinant antigens of spring viremia of carp virus and infectious salmon anaemia virus. The expression of these plant-based recombinant vaccines was confirmed by immunodetection, which was supported by fluorescence observation, specifically in the seed endosperm. The antigenicity of transgenic plant material containing recombinant antigens was evaluated using an intubation model of common carp (Cyprinus carpio), revealing a substantial upregulation of the immunoglobulin transcripts in both systemic and mucosal tissues over a period of 28 days following a single dose of transgenic antigens. Collectively, these results underscore the potential of barley-based recombinant vaccines for disease prevention in fish aquaculture. [Display omitted] • Oral vaccines in aquaculture face degradation, poor absorption/immune recognition. • Plant-based vaccines are more stable and include natural adjuvants. • Barley was explored as a platform for producing oral subunit vaccines. • Protein expression of several viral antigens in barley was achieved. • An intubation model showed increased immunoglobulin transcripts in carp. [ABSTRACT FROM AUTHOR]

This review delves into the increasing interest in probiotics and paraprobiotics as a viable alternative to antibiotics in aquaculture, highlighting their potential to enhance fish health and prevent diseases. As the aquaculture industry continues its global expansion, addressing the challenges associated with disease outbreaks in high-density fish populations becomes imperative. The review underscores the promising role of probiotics and paraprobiotics as a sustainable strategy to mitigate these challenges. The diverse positive impacts of various probiotic strains such as Arthrobacter , Bacillus , Lactobacillus , Bifidobacterium , Clostridium , and others emphasize their roles in enhancing growth, resistance to diseases (including bacterial, viral, and parasitic infections), stress reduction, water quality management, and environmental sustainability. Challenges such as stability, host specificity, and regulatory considerations must be addressed to optimize the use of probiotics in aquaculture. Additionally, paraprobiotics, or non-viable microbial cells, present a safer alternative to the criticized antibiotics and even live probiotics in environments where microbial viability poses a risk. These inactivated cells retain the ability to modulate the immune system and improve gut health, offering a promising complementary approach to fish disease prevention. The review advocates for a systematic approach combining research, innovation, and collaboration to effectively integrate probiotics and paraprobiotics into fish farming practices. Furthermore, the mechanisms by which probiotics and paraprobiotics modulate gut microbiota, produce antimicrobial compounds, and strengthen fish's immune system have been elucidated. Moreover, the practical applications of probiotics in fish farming, including optimal administration methods and the challenges and limitations faced by the industry, have been discussed. Emphasis on the importance of continued research to explore new probiotic and paraprobiotic strains and develop innovative delivery systems to ensure the sustainability of aquaculture has been discussed. By enhancing fish health, reducing the need for antibiotics, and improving water quality, probiotics, and paraprobiotics contribute to more sustainable and environmentally responsible aquaculture operations. [ABSTRACT FROM AUTHOR]

The biofloc technology (BFT) in sea cucumber (Apostichopus japonicus) farming utilizes nutrient cycling, driven by heterotrophic microorganisms, to improve water quality and promote sustainable aquaculture. This study explored the potential of sodium bicarbonate and sodium acetate as novel carbon sources, which may offer advantages in maintaining water stability and enhancing microbial diversity compared to traditional carbon sources. Juvenile sea cucumbers were cultured in a 64‐day trial and assigned to five treatment groups: S (sucrose), SSa (S + sodium acetate), SSb (S + sodium bicarbonate), Nc (no carbon source), and Cg (control group), each treatment group was repeated three times (n = 3). The inclusion of sodium bicarbonate and sodium acetate significantly improved water quality parameters. The group SSb exhibited a higher pH (8.28), and significantly lower ammonia nitrogen (0.501 mg L−1), and nitrite levels (0.031 mg L−1) compared to other groups. Additionally, the biofloc volume (BFV; 17 mL L−1), total suspended solids (TSSs; 238 mg L−1), and protein content (13.9%) in the group SSb were all within the tolerance range for sea cucumbers. Group SSb also showed the significantly highest weight gain rate (WGR; 78.5%) and specific growth rate (SGR; 0.91%), alongside increased enzyme activities, including superoxide dismutase (SOD; 179 U mL−1) and peroxidase (POD; 1.59 U mL−1), which were significantly higher than those in other groups. Furthermore, the group SSb demonstrated enhanced gut microbiota diversity, characterized by a higher abundance of beneficial Bacillus and lower levels of harmful Vibrio and Pseudomonas. The addition of SSb significantly improved water quality by maintaining optimal pH and reducing harmful nitrogen compounds, which in turn supported enhanced physiological growth and increased gut microbiota diversity, indicating its potential as a superior carbon source in biofloc systems. [ABSTRACT FROM AUTHOR]

Background: In recent years, the total production of mud crab Scylla paramamosain has been declining, and the breeding areas are faced with land shortage and shortage of breeding production, which needs to be solved urgently. S. paramamosain can survive and grow in a wide range of salinities is an excellent variety suitable for saline-alkali water aquaculture. As a species with high economic value and strong adaptability to the environment, its cultivation under low salt conditions can not only improve the utilization efficiency of saline-alkali land, but also provide new possibilities for the sustainable development of aquaculture. Results: A total of 248 different metabolites were identified by LC/GC-MS in the intestinal tract of S. paramamosain. These different metabolites were mainly concentrated in 'Lipids and lips-like molecules'. Among them, 112 metabolites are upregulated, and among these upregulated metabolites are mainly 'Fatty Acyls' and 'Glycerophospholipids'. The upregulation of these metabolites indicates an increase in lipid storage of S. paramamosain, which may increase the resistance of S. paramamosain to adverse environmental stress. Among them, 136 metabolic differentiates were down-regulated, mainly 'Carboxylic acids and derivatives'. The down-regulation of these organic acids may indicate that organic acids are used as energy sources for the immune response to long-term environmental stress. Conclusion: Under long-term chloride type low-salt saline-alkali water stress, S. paramamosain will shift to another homeostasis for development. [ABSTRACT FROM AUTHOR]

Aquaculture is one of the most significant food sources from the prehistoric period. As aquaculture intensifies globally, the prevalence and outbreaks of various pathogenic microorganisms cause fish disease and heavy mortality, leading to a drastic reduction in yield and substantial economic loss. With the modernization of the aquaculture system, a new challenge regarding biofilms or bacterial microenvironments arises worldwide, which facilitates pathogenic microorganisms to survive under unfavorable environmental conditions and withstand various treatments, especially antibiotics and other chemical disinfectants. However, we focus on the mechanistic association between those microbes which mainly form biofilm and probiotics in one of the major food production systems, aquaculture. In recent years, probiotics and their derivatives have attracted much attention in the fisheries sector to combat the survival strategy of pathogenic bacteria. Apart from this, Bibliometric analysis provides a comprehensive overview of the published literature, highlighting key research themes, emerging topics, and areas that require further investigation. This information is valuable for researchers, policymakers, and stakeholders in determining research priorities and allocating resources effectively. [ABSTRACT FROM AUTHOR]

Schizothorax lissolabiatus and Schizothorax griseus are native Chinese fish species with significant ecological and economic importance. We wanted to support sustainable aquaculture practices by exploring the differences in metabolic, histological, and microbiota between the two Schizothorax species. This study analyzed and compared the digestive enzyme activities, metabolic indicators, gut histology, and microbiota composition of S. lissolabiatus and S. griseus under identical farming conditions. Our comparative analysis reveals both shared characteristics and species-specific differences. While a-amylase and trypsin activities showed no significant differences between species, a consistent trend was observed, with enzyme activity highest in the hindgut, followed by the midgut, foregut, esophagus, and liver. In terms of specific metabolic markers, S. griseus shows higher lipase activity in the liver and foregut, as well as higher aspartate aminotransferase and catalase levels in the liver, along with an increased serum glucose content compared to S. lissolabiatus. Serum metabolomics analysis revealed 21 differentially abundant metabolites linked to glycerophospholipid metabolism, autophagy, purine metabolism, and necroptosis, reflecting distinct metabolic adaptations and nutritional needs for each species. These metabolic differences provide a basis for optimizing feed composition and aquaculture practices tailored to each species. Notably, S. lissolabiatus displays a significantly higher goblet cell count in the hindgut compared to S. griseus. Additionally, both species exhibit greater villi number, length, width, crypt depth, and muscle thickness in the esophagus than in the foregut, midgut, and hindgut. S. griseus also has a higher number of operational taxonomic units (OTUs) and greater microbial diversity in its intestinal microbiota, which may enhance its nutrient utilization capabilities. While both species' dominant microbial phyla include Fusobacteria, Firmicutes, Proteobacteria, and Bacteroidetes, S. griseus demonstrated superior lipid digestion capabilities. Furthermore, the midgut and hindgut in both species display higher starch and protein digestive enzyme activities than other digestive tissues. These findings highlight the physiological differences between the two Schizothorax species, suggesting targeted strategies to improve health, growth, and sustainability in aquaculture. [ABSTRACT FROM AUTHOR]

Simple Summary: In recent decades, there has been a global issue in searching for fish meal (FM) alternatives as a protein source due to the decreasing supply of FM, which caused a price surge. Although there is a scarcity of protein sources all over the world, a lot of by-products, despite high nutritive values, are wasted away, or the suitability of those by-products as protein sources has not been investigated in all commercially important species worldwide. Although tuna by-product meal (TBM) is considered one of the promising alternative protein sources, there is no information on its application as a protein source in the diet of juvenile greater amberjack Seriola dumerili. After replacing different levels of FM protein with TBM in the diet of juvenile greater amberjack, this study found that TBM can replace at least 14.5% of FM protein without compromising the growth and health status of this species. It also suggests that TBM-based diets will be ecofriendly by reducing phosphorus load to the environment. These results would be supportive of the sustainable development of aquaculture for this commercially important species. The suitability of tuna by-product meal (TBM) as a replacement for fish meal (FM) in the diet of juvenile greater amberjack Seriola dumerili was investigated for its effect on growth, mercury (Hg) levels in the fish body, phosphorus (P) load, and plasma chemistry. FM was the main protein source in the control diet (C), and it was replaced by TBM at 25%, 50%, 75%, and 100% to formulate diets TM25, TM50, TM75, and TM100, respectively. The experiment was performed in triplicate, stocking 30 juveniles (mean weight: approximately 6.7 g) in each 500 L tank. After a 42 d rearing period, there were no significant differences in growth, nutrient digestibility, or productive value between diets C and TM25. However, a quadratic polynomial regression analysis suggested that the optimal dietary level of TBM against final weight was 14.5%. A significant linear correlation was observed between Hg in the diet and fish whole body, but the level was far lower, posing health risks to humans. Owing to the lower P intake of fish fed with the TBM-based diets, their P load was significantly reduced compared to the control group. Plasma levels of total protein, total cholesterol, and albumin in the TM75 and TM100 groups were significantly lower than those in the C, TM25, and TM50 groups. These results suggest that 14.5% of FM protein can be replaced by TBM protein in the diet of juvenile greater amberjack and that a significant reduction in P load can be achieved with a TBM-based diet. [ABSTRACT FROM AUTHOR]

Simple Summary: Aquaculture suffers from losses due to disease outbreaks, and to keep the industry sustainable, there are strict limitations on antibiotic use. Therefore, several alternatives have been suggested, such as probiotics. Bacillus and Lactobacillus species are among the most studied and advised probiotics for aquaculture. However, researchers are now looking for other probiotic bacteria that can be used in aquaculture. In this context, non-lactic acid bacteria (non-LAB), which are mainly host-associated, should have promising effects on fish and shellfish. Given the potential and advantages of this kind of probiotics, the present review paper provides detailed information on the use of various non-LAB bacteria and provides a roadmap to future studies on new probiotics for sustainable aquaculture. With the intensification of aquaculture to meet the rising demands of fish and shellfish, disease outbreaks during the larval and adult stages are a major challenge faced by aqua culturists. As the prophylactic use of vaccines and antibiotics has several limitations, research is now focused on sustainable alternatives to vaccines and antibiotics, e.g., medicinal plants, probiotics, postbiotics, prebiotics, and synbiotics, as promising candidates to strengthen the immune response of fish and shellfish and to control disease outbreaks. With respect to probiotics, numerous studies are available revealing their health-promoting and beneficial impacts in aquaculture. However, most studies focus on Bacillus and Lactobacillus species. Keeping in view the positive effects of probiotic lactic acid bacteria in aquaculture, researchers are now looking for other probiotic bacteria that can be used in aquaculture. Recently, many non-lactic acid bacteria (non-LAB), which are mainly host-associated, have been reported to reveal beneficial effects in fish and shellfish aquaculture. The main non-LAB probiotic genera are Bifidobacterium, Clostridium, Microbacterium, Micrococcus, Paenibacillus, Acinetobacter, Alcaligenes, Enterobacter, Phaeobacter Pseudoalteromonas, Pseudomonas, Pseudomonas, and Vibrio. Despite the promising effects of non-LAB probiotics, comparably, there is limited available information in this context. This review focuses only on probiotic strains that are non-LAB, mostly isolated from the host digestive tract or rearing water, and discusses their beneficial effects in fish and shellfish aquaculture. This review will provide detailed information on the use of various non-LAB bacteria and provide a roadmap to future studies on new probiotics for sustainable aquaculture. [ABSTRACT FROM AUTHOR]

Simple Summary: Fishmeal is commonly used in aquafeed manufacturing. However, the global market price of fishmeal is highly fluctuating, and it is not the most sustainable solution. Therefore, the aquafeed industry is often exploring alternative protein sources such as insect meal to replace fishmeal. Our study involved testing diets where 10%, 30%, and 50% of the fishmeal was replaced with black soldier fly larvae to observe how this affects digestion and gut bacteria diversity in hybrid grouper. The dietary group with 10% substitution showed higher levels of enzymes that help break down food and absorb nutrients effectively. In contrast, the diets with 30% and 50% replacements showed signs of weakening in the intestinal walls, which could negatively affect nutrient absorption. Moreover, the variety of gut bacteria in the groups with 10% and 50% replacement was greater, with modifications observed in the biological functions associated with energy and nutrient processing. Our results suggest that replacing some fishmeal with black soldier fly larval meal could potentially improve gut health and promote the development of sustainable aquaculture diets. This study examined the diversity and responses of intestinal microbiota in hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂) fed diets with varying levels of fishmeal replaced by black soldier fly larvae (BSFL). The 10% BSFL substitution (BSFL10) group showed the highest levels of trypsin and amylase. Substituting fishmeal with 30% and 50% BSFL weakened the intestinal wall, resulting in vacuoles, sparse striatal boundaries, and fewer villi. Microbiota diversity, measured through Shannon's index, was higher in the BSFL10 and BSFL50 groups than in the control. 16S rRNA amplicon data revealed the dominance of Firmicutes, Proteobacteria, Bacteroidetes, Spirochaetota, and Verrucomicrobia phyla. The BSFL-replacement groups showed an increase in Proteobacteria, Bacteroidetes, and Spirochaetota compared to the control, but fewer Firmicutes. PICRUSt analysis indicated significant alterations in microbial function, particularly enhanced protein, carbohydrate, lipid, and energy metabolisms in the BSFL-fed group. Substituting 10% fishmeal with BSFL enhanced nutrient metabolism and gut microbiota in juvenile hybrid grouper. Further research is needed to explore factors affecting the efficacy of insect feed as a sustainable aquaculture diet. [ABSTRACT FROM AUTHOR]

Recirculating aquaculture systems (RASs) are a sustainable aquaculture model strongly advocated by Chinese government. Earthy-musty is an important factor affecting the economic benefit and food safety of RAS. Geosmin (GSM) and 2-methylisobornyl (2-MIB) are the main substances that produce earthy-musty, which have a low human sensory threshold. Their accumulation leads to the earthy-musty of aquatic products, which greatly reduces the taste and economic value of these products and also threatens the sustainable development of aquaculture in China. GSM and 2-MIB are predominantly produced by heterotrophic prokaryotes in RASs. The production of these odorants is closely related to environmental factors, water quality parameters, and microbial community composition and is regulated by functional enzymes. Since the water exchange rate of RASs is only 5%, the current earthy-musty substances (EMS) treatment technology is not suitable for this system, and a cost-effective EMS removal technology is urgently needed. We put specific emphasis on the removal of EMS in RAS farms. Finally, we predict the challenges faced by EMS purification in RASs under the "comprehensive development of aquaculture" guideline by the Chinese government. In this review, first, we discuss the current GSM and 2-MIB generation mechanism in RASs, and then, based on the characteristics of RASs, we describe the transformation rules and removal methods of EMS in water systems and aquatic products, respectively. Finally, a new idea for removing EMS in RASs is proposed; that is, lipid adsorbents cooperate with functional microflora to remove EMS. This review provides scientific basis for eliminating the off-flavor of aquatic products, providing technical support for the promotion of RASs. [ABSTRACT FROM AUTHOR]

Biofloc technology (BFT) has been identified as an effective and sustainable aquaculture method, particularly beneficial for warm-water species in tropical areas. This technology is widely used in intensive aquaculture for several aquatic species due to its capacity to significantly reduce water exchange rates, benefiting both production systems and the environment. The efficacy of BFT in farming operations is directly related to a proper management of water quality parameters within the optimal range of the target species, as these parameters directly impact the yield of production units. Essentially, BFT functions as a water quality management system, converting harmful nitrogenous waste such as ammonia and nitrite into less harmful forms such as nitrates through microbial activity, ensuring the health of aquatic organisms. Key environmental factors such as temperature, dissolved oxygen (DO), pH, salinity, alkalinity, TAN, nitrite, nitrate, settleable solids (SS), and total suspended solids (TSS) can affect the growth of aquatic species and the functionality of the microbial community. This review brings (i) a comprehensive bibliometric analysis on biofloc and water quality, (ii) highlights optimal ranges, and (iii) key observations of several water parameters including temperature, salinity, nitrogenous compounds, SS, TSS, DO, phosphate, pH, and alkalinity in BFT rearing conditions for key aquatic species. Elements such as countries, thematic and keywords, and authors were explored, correlated, and discussed. In addition, this manuscript also (iv) discusses the presence of heavy metals and microplastics (MPs) in BFT culture water. A dedicated review on water quality in biofloc technology will contribute to future research and development (R&D) in this topic, support decision-making to improve farming operations, and can help further expansion of BFT-based aquaculture. [ABSTRACT FROM AUTHOR]

The aquaculture industry is suffering from significant financial setbacks due to an increasing frequency of disease outbreaks, posing a threat to the sector's sustainability. Various bacterial, viral, parasitic, and fungal pathogens have led to massive mortalities in farmed fish worldwide. Throughout the years, the management of fish diseases has predominantly centered around the utilization of conventional antibiotics and chemicals. Nevertheless, their indiscriminate use has given rise to serious implications, including an increase in resistant pathogens, disruptions in the metabolic processes of fish, degradation of the aquatic environment, the presence of drug residues in aquatic products, and a potential threat to human health. Various effective bio-based and immunoprophylaxis alternative therapies have been developed to overcome these impediments. Recent alternative therapeutic approaches to fish diseases encompass a range of strategies, including phytotherapeutics, nanotherapeutics, probiotics, prebiotics, synbiotics, phage therapy, vaccination, quorum quenching, antimicrobial peptides, biosurfactants, bacteriocins, stem cells, and diagnostic-based therapy. Advancements in biotechnology have significantly enhanced the efficacy of these therapies. However, additional research is essential to refine the utilization of these therapeutic approaches. Critical concerns, such as efficacy, cost, risks, availability, and adverse effects on fish and the ecosystem, need to be addressed to establish guidelines for their sustainable application in aquaculture. This review will increase aquaculturists' awareness of recent therapies used in fish farming, their mechanisms, challenges, and impacts while promoting the sustainability of commercial aquaculture. [ABSTRACT FROM AUTHOR]

The study examines the impact of integrated biofloc technology (BFT), different salinity levels, and their combined effects over 90 days on various physiological parameters. The investigation includes growth performance and feed utilization, water quality, the chemical composition of biofloc and fish, digestive enzymes, reproductive performance, stress and biochemical indicators, and antioxidant-immune responses in red tilapia (Oreochromis spp.) broodstock. The fish were initially weighed (males: n = 270; 104 ± 0.96 g; females: n = 270; 93.2 ± 0.66 g) and subsequently divided into 12 treatment groups (6 for males and 6 for females) spread across 36 separate tanks (3 tanks per treatment; 45 fish per treatment; 15 fish/tank). The treatments involved three salinity levels (18, 28, and 36 ppt) in both clear water (CW) and BFT systems. The outcomes demonstrated that fish in the 36 ppt salinity with BFT treatment demonstrated significant improvements (P < 0.05) in growth parameters (final body weight, weight gain, and specific growth rate, feed intake, and feed conversion ratio). The condition factor in BFT groups increased in all salinity situations. The survival rates of broodstock were consistently high in all experimental conditions The study found that BFT and salinity significantly impacted (P < 0.05) whole body contents (moisture, protein, lipid, and ash) in both males and females. Water quality parameters showed variations between BFT and CW, with notable impacts (P < 0.05) on dissolved oxygen and pH. The BFT and salinity influenced digestive enzyme activities (protease, amylase, and lipase) and reproductive performance (males) and the 36 ppt salinity with BFT recorded the highest values. The hemato-biochemical and antioxidant-immune responses were also impacted by BFT and salinity exposure. The study highlights the potential benefits of incorporating BFT into red tilapia aquaculture systems, particularly in optimizing growth, health, and reproductive performance under various salinity conditions, which can enhance sustainable intensification, disease control, and environmental stewardship. [ABSTRACT FROM AUTHOR]

Highlights: The anammox process has significant potential to treat nitrogen-rich marine RAS WW. The marine anammox species Ca. Scalindua demonstrated effective treatment of synthetic WW with high NO3− levels typically encountered in RAS, at a laboratory scale. Despite a relative decline in the population over time, Ca. Scalindua remained a key species within the anammox granules and sustained a high nitrogen removal rate over a period of 262 days of exposure to elevated NO3− levels. Recirculating aquaculture systems (RAS) hold significant potential for sustainable aquaculture by providing a stable, controlled environment that supports optimal fish growth and welfare. In RAS, ammonium (NH4+) is biologically converted into nitrate (NO3−) via nitrite (NO2−) by nitrifying bacteria. As a result, NO3− usually accumulates in RAS and must subsequently be removed through denitrification in full RAS, or by regular water exchanges in partial RAS. The marine anammox bacteria Candidatus Scalindua can directly convert toxic NH4+ and NO2− into harmless nitrogen gas (N2) and has previously been identified as a promising alternative to the complex denitrification process or unsustainable frequent water exchanges in marine RAS. In this study, we evaluated the impact of high NO3− levels typically encountered in RAS on the performance and abundance of Ca. Scalindua in a laboratory-scale bioreactor. The bacterial composition of the granules, including the relative abundance of key nitrogen-cycling taxa, was analyzed along with the functional profile (i.e., NH4+ and NO2− removal efficiencies). For this purpose, a bioreactor was inoculated and fed a synthetic feed, enriched in NH4+, NO2−, minerals and trace elements until stabilization (Phase 1, 52 days). NO3− concentrations were then gradually increased to 400 mg·L−1 NO3−-N (Phase 2, 52 days), after which the reactor was followed for another 262 days (Phase 3). The reactor maintained high removal efficiencies; 88.0 ± 8.6% for NH4+ and 97.4 ± 1.7% for NO2− in Phase 2, and 95.0 ± 6.5% for NH4+ and 98.6 ± 2.7% for NO2− in Phase 3. The relative abundance of Ca. Scalindua decreased from 22.7% to 10.2% by the end of Phase 3. This was likely due to slower growth of Ca. Scalindua compared to heterotrophic bacteria present in the granule, which could use NO3− as a nitrogen source. Fluorescence in situ hybridization confirmed the presence of a stable population of Ca. Scalindua, which maintained high and stable NH4+ and NO2− removal efficiencies. These findings support the potential of Ca. Scalindua as an alternative filtering technology in marine RAS. Future studies should investigate pilot-scale applications under real-world conditions. [ABSTRACT FROM AUTHOR]

The striped snakehead, Channa striata, is commercially and nutritionally important due to its medicinal properties, such as wound healing and antimicrobial abilities. This study investigated the reproductive biology of C. striata in relation to hydro-climatic changes using a fuzzy logic approach for long-term management in the wetland ecosystem (Gajner beel), Bangladesh. A total of 1200 C. striata individuals were collected monthly during January to December 2019 using various fishing methods. Measurements of total length (TL), body weight (BW), and gonad weight (GW) were taken with a precision of 0.01 cm and 0.01 g, respectively. The GSI (gonadosomatic index in %), MGSI (modified gonadosomatic index in %), and DI (Dobriyal index) were used to determine size at sexual maturity (Lm) and the spawning season. Results revealed a wide range of TL, ranging from 12.7 to 46 cm. The Lm was estimated between 21.7 and 25.33 cm based on various model as TL vs. GSI, MGSI, and DI; TL-fork length (FL) regressions; and maximum length (Lmax) for this species. The spawning period was observed from April to July, peaking in May, indicated by higher GSI, MGSI, and DI values. Eco-climatic factors showed a significant relationship with GSI, except for total dissolved solids (TDS). Rising temperatures and declining rainfall could delay spawning of C. striata. A fuzzy logic approach was employed to predict future GSI changes over extended periods (e.g., 50 or 60 years), enabling anticipation of shifts in the timing and duration of the spawning season. Finally, the findings of our research might be effective to carry out specific conservation efforts of C. striata in response to climate variability in sub-tropical water. [ABSTRACT FROM AUTHOR]

Biofloc technology (BFT) is a relatively new microbial‐based cultivation system that can be adopted to accomplish more sustainable aquaculture and circularity goals. This review explores aspects of BFT integrating the utilization of probiotics and phytobiotics as dietary and water supplements. This scientific‐based snapshot unpacks some physiological pathways and brings a literature review on how these supplements can boost water quality, as well as aquatic species' growth, health, and survival. Probiotics, live microorganisms that confer health benefits on the host when administered in adequate dosage, are noted for their ability to bolster animal defenses and sustain water quality in farming conditions. Recent studies showcased that selected bacteria, yeast, and fungi, once added into biofloc‐based systems can enhance animal performance, act as a tool for water quality management and protect fish and crustaceans against diseases. On the other hand, phytobiotics are additives sourced from plants that normally are added into compounded feeds and are known for their health and growth benefits in aquatic animals. These additives contain plant‐based substances/extracts that play a key role to suppress inflammation, pathogens, and can also act as antioxidants. These selected ingredients can promote healthy gut microbiota, improve feed efficiency, and turn on genes responsible for immunity improving disease resistance of fish/shrimp. According to this review, the adoption of probiotics and phytobiotics in BFT can greatly increase farm outputs by producing healthier animals, as well as promoting growth and consistent yields. Lastly, this review showcases the importance of proper section of probiotics and phytobiotics in order to achieve a functioning BFT. Despite its numerous advantages, BFT faces several challenges, especially related to microbial management. Probiotics and phytobiotics are practical tools that can play a crucial role to obtain a more stable environment with a desirable microbial population in water and gut. Future directions in the field should focus on optimizing the utilization of these supplements for a more resilient and sustainable BFT aquaculture. [ABSTRACT FROM AUTHOR]

The latest strain of Oreochromis niloticus is an altered ecological adaptation for sustainable aquaculture and is necessary to sustain stocking density and reduce physiological stress of the new strain. The present study aimed to determine the optimum stocking density, biological performance, and economic efficiency of the Nile tilapia. The 14,000 healthy seeds and uniform weight (40 ± 2.4 g) sex‐reversed Oreochromis niloticus were stocked in four cages, which are cage (1) 20 fish/m3, cage (2) 30 fish/m3, cage (3) 40 fish/m3, and cage (4) 50 fish/m3. The fish were fed 30% dietary protein and feeding frequency three times per day and the feeding rate adjusted according to the fish body weight. Results showed a significantly higher growth, weight gain, and specific growth rate in Nile tilapia stocking density on cage (1), 20 fish/m3 and cage (2), 30 fish/m3 compared to cage (3), 40 fish/m3 and cage (4), 50 fish/m3 (p < .05). The survival and growth rate showed an inverse relationship with stocking density. The feed conversion ratio (FCR) is the lowest in cage (1) and cage (2), which is significantly different from those of other cages (p < .05). The profit index (%) was significantly higher at low density. There was no significant variation in the HSI, VSI and CF. The digestive enzymes such as lipase and amylase were secreted highly in the cages (3) and (4) but high protease was secreted in cage (1). The lipid, ash, and protein of the whole fish were reduced to a lower density, but the moisture levels in the fish bodies raised significantly (p < .05) with increasing stocking density. The phenomenal regression indicates that 25–35 fish/m3 are optimum stocking density for Nile tilapia in the cage culture system. The current study has made significant step toward optimizing the stocking density of a new strain and developing cage culture in Pakistan. [ABSTRACT FROM AUTHOR]

Spinibarbus sinensis and Spinibarbus caldwelli are important economic freshwater fish in China. They are popular among consumers and farmers due to their delicious meat, high nutritional value, strong disease resistance and ease of cultivation. As two important species in China, the number of Spinibarbus sinensis and Spinibarbus caldwelli has been increasing in recent years. There are relatively few studies on the nutritional feeds of Spinibarbus sinensis and Spinibarbus caldwelli, especially on their lipid and carbohydrate requirements, which are crucial for the development of artificial feeds and the sustainable development of the industry. In this paper, the nutrient requirements of protein, amino acids, lipid and fish meal substitution in compound feeds as well as feed additives of Spinibarbus sinensis and Spinibarbus caldwelli are summarized, It aims to provide data reference for the research and development of their compound feeds and promote the sustainable development of their aquaculture industry. [ABSTRACT FROM AUTHOR]

The increase in the global population has been accompanied by an increase in demand for animal protein, consequently driving the growth of the aquaculture sector as a sustainable solution to satisfy this demand. Observing the growth of animals in farm environments is vital to assess the efficiency of feeding methods, identify health problems or environmental stressors, and help implement sustainable practices. The application of cameras enables remote monitoring of various environments and activities in real time, providing quick insights, improving security measures, and facilitating decision-making based on the collected data. This paper proposes a low-cost camera system and an image processing-based strategy to monitor and measure the size of Pacific oysters inside a tank. The fast segment anything model algorithm is implemented in the Python programming language to perform image segmentation and generate object masks for subsequent processing. The size of oysters is obtained by measuring the distance between the parallel lines of the bounding box that is generated surrounding them. The largest absolute errors and relative errors for the estimates were 3 mm and 5.13%, respectively, when compared to measurements made manually. Furthermore, the width and height have standard deviations of 0.6 and 0.3 mm, respectively, indicating low data dispersion and good repeatability of the algorithm. Since the accuracy of the human eye in estimating a dimension without the aid of a distance measuring instrument tends to be lower than that obtained by the proposed tool, it is believed that the approach can significantly contribute to the management of oyster farm production, providing strategic insights based on animal growth for producers. [ABSTRACT FROM AUTHOR]

The structural hydrodynamic response of longline aquaculture facilities under the influence of waves and currents is complex. Studying the hydrodynamic characteristics of this aquaculture structure in complex sea environments can contribute to sustainable offshore aquaculture solutions. Thus, we established a numerical model using AquaSim2.18, a proven and effective finite element hydrodynamic software for analyzing the maximum tension in mooring lines and main lines, the displacement of the main lines, and the forces on the lantern nets under waves and currents. The results showed that positioning the system in the direction of incidence of waves and currents minimizes tension in both mooring and main lines, making a downstream arrangement optimal; compared with a single row, the maximum reduction in the tension of the mooring lines is 3.3% and 1.8% for five-row and row-row lines, respectively, and the shadow effects reduced the downstream mooring force. Additionally, line tension increased with wave height and current velocity, whereas wave periods had variable effects due to the period range; the lantern net forces increased with wave height and decreased with wave period. Wave height was also shown to influence the horizontal displacement of main lines. The findings can provide a reference for the hydrodynamic characteristics of different components of the structure. [ABSTRACT FROM AUTHOR]

The growing global population and limitations in fish catch production have led to a surge in the demand for aquaculture. Contaminants of emerging concern (CEC) are frequently being detected at low levels in surface water. These CECs, which include previously unidentified or unregulated pollutants, pose potential risks to health and the environment, though their impacts are not yet fully understood. Extensive research studies have been proposed and undertaken to address the issue of aquaculture wastewater, aiming to minimize its impact and implement effective treatment methods. This review provides an analysis of various technologies used for treating aquaculture wastewater using advanced oxidation processes (AOPs) focusing on photocatalysis and ozonation. It examines their advantages and disadvantages, as well as their respective treatment efficacies, and discusses their potential applications in sustainable aquaculture practices complying with the Sustainable Development Goals of 1, 2, and 6 as well as being in line with the Environmental Social and Governance (ESG) framework. [ABSTRACT FROM AUTHOR]

Simple Summary: This review article depicts the fish immune system and vaccination, focusing on mucosal vaccines. It underscores the distinctive features of the fish immune system, including mucosal and systemic immune responses that serve as defenses against various types of pathogens. The article further explores the different types of available fish vaccines. Mucosal vaccines are highlighted for their capacity to elicit robust local and systemic immune responses, enhancing disease resistance and promoting overall fish health in addition to significantly contributing to the overall health and well-being of fish populations, making them a crucial element in aquaculture and fisheries management. The growing role of aquaculture in global food security has underscored the need for advanced immunological insights to protect fish health and boost productivity. As aquaculture's importance rises, understanding fish immunity is crucial for developing effective vaccination strategies. Fish possess a specialized immune system with unique mucosal structures that enable resilience in aquatic environments. This review examines critical advances in fish mucosal immunity, particularly focusing on mucosal vaccines that target infection at primary entry points, such as the gills, skin, and gastrointestinal tract. Mucosal vaccination has demonstrated a compelling capacity to stimulate localized and systemic immune responses, offering enhanced protection against waterborne pathogens. Additionally, this review addresses knowledge gaps from previous research on the global aquaculture vaccines market by offering a regional perspective on industry developments, recent trends, and innovative vaccine formulations. In doing so, it highlights the role of mucosal vaccines in overcoming the specific challenges of fish farming and supporting sustainable aquaculture. This synthesis of current methodologies, industry practices, and future directions contributes to a deeper understanding of fish immunology, ultimately informing strategies to achieve optimal disease management and bolster global aquaculture resilience. [ABSTRACT FROM AUTHOR]

The sustainable management of aquaculture by-products is crucial for advancing circular economy practices. Mediterranean mussel shell waste, rich in calcium carbonate, presents a sustainable alternative to conventional liming materials, especially for mitigating soil acidification, a very important and common issue that limits crop productivity. This study evaluated the effectiveness of processed mussel shell waste in enhancing soil pH, organic matter, and nutrient availability. A 180-day pot experiment using highly acidic soil (pH < 4.5) collected from a local field was conducted in a Completely Randomized Design. Treatments involved two grain sizes of mussel shell powder (Fine: <1 mm; Coarse: 1–2 mm) at rates between 0.1 and 6%. Treated soil pH was measured monthly, whereas organic matter, available phosphorus (P), and exchangeable potassium (K) were measured at the beginning and the end of the experiment. The results revealed significant improvements in pH, organic matter, available phosphorus (P), and exchangeable potassium (K), particularly in the Fine Powder treatments. However, total nitrogen (N) remained unaffected. These findings highlight the potential of mussel shells as an eco-friendly and cost-effective amendment, advancing sustainable agriculture and waste recycling, thus contributing to broader conservation efforts by reducing the environmental footprint of aquaculture waste and supporting biodiversity and ecosystem resilience through sustainable resource management. [ABSTRACT FROM AUTHOR]

This review evaluates regenerative aquaculture (RA) technologies and practices as viable pathways to foster resilient, ecologically restorative aquaculture systems. The key RA technologies examined include modern periphyton technology (PPT), biofloc technology (BFT), integrated multitrophic aquaculture (IMTA), and alternative feed sources like microalgae and insect-based diets. PPT and BFT leverage microbial pathways to enhance water quality, nutrient cycling, and fish growth while reducing environmental pollutants and reliance on conventional feed. IMTA integrates species from various trophic levels, such as seaweeds and bivalves, to recycle waste and improve ecosystem health, contributing to nutrient balance and reducing environmental impact. Microalgae and insect-based feeds present sustainable alternatives to fishmeal, promoting circular resource use and alleviating pressure on wild fish stocks. Beyond these technologies, RA emphasizes sustainable practices to maintain fish health without antibiotics or hormones. Improved disease monitoring programs, avoidance of unprocessed animal by-products, and the use of generally recognized as safe (GRAS) substances, such as essential oils, are highlighted for their role in disease prevention and immune support. Probiotics are also discussed as beneficial microbial supplements that enhance fish health by promoting gut microbiota balance and inhibiting harmful pathogens. This review, therefore, marks an important and essential step in examining the interconnectedness between technology, agroecology, and sustainable aquaculture. This review was based on an extensive search of scientific databases to retrieve relevant literature. [ABSTRACT FROM AUTHOR]

Increasing antibiotic resistance poses an urgent global public health threat and a serious concern worldwide. Bacteriophage (phage) therapy has been identified as a promising alternative to antibiotics for treating bacterial diseases in both humans and animals. The excessive use of antibiotics in aquaculture is a major threat to sustainable aquaculture, promoting the spread of antibiotic resistance in the aquaculture environment and the contamination of aquaculture products with antibiotic residues. Consequently, interest in alternative approaches that reduce reliance on antibiotics has grown within the aquaculture sector. As a promising alternative, extensive phage research targeted at aquaculture has demonstrated the protective efficacy of phages against diseases in aquatic animals. Although numerous studies have employed in vitro models, research supported by in vivo experiments remains scarce. Without in vivo evidence, phage therapy cannot fulfill the requirements of aquaculturists. The first part of this review outlines the bacterial diseases severely affecting the health and survival of aquatic animals. The second part provides updates on phage applications for the therapy and prophylaxis of pathogenic bacterial infection in aquatic animals, including administration routes and key accomplishments. Therefore, this review provides insights into effective real-world phage biocontrol strategies that enable sustainable aquaculture. [ABSTRACT FROM AUTHOR]

Globally, aquaculture is evolving in new directions achieving the critical goal of sustainable global aquaculture. A good larval-rearing diet is essential for the cultivation of aquaculture species, especially in larvae growth, survival and disease resistance. However, the success of larval rearing has been limited by the early use of artificial meals. Zooplankton are used as feed to fish/shrimp larvae in aquaculture due to their high nutrient content and easy digestibility. Enrichment methods are practised because they can manipulate the nutritional composition of zooplankton to meet the nutritional requirements of the fish/shrimp larvae. It is necessary for the improvement, growth and development during the first feeding phase of the larvae because fish require balanced and high-protein diets. Examining the most recent advancements in this field, this review focuses on the techniques for enriching zooplankton with vital nutrients and probiotics. It emphasizes how these improvements affect the nutritional value of zooplankton and the well-being of organisms cultivated. We also address the challenges and constraints of the enrichment method. This review attempts to offer insights into the future directions and potential advantages of zooplankton enrichment in boosting aquaculture productivity and sustainability through a thorough analysis of previous studies and breakthroughs. [ABSTRACT FROM AUTHOR]

Pectinidae species are prominent shellfi sh in the Adriatic Sea, valued for their commercial and ecological importance. Among them, the queen scallop, Aequipecten opercularis, has not yet demonstrated long-term viability in captivity, posing challenges for aquaculture. However, successful aquaculture of A. opercularis could reduce the adverse effects of fishing gear on sea bottoms. The objective of this study is to offer perspectives on how queen scallops adapt to captive conditions, examining their morphometric response and shell growth over three months under different seawater parameters. We assessed the growth rate and hemocyte count in the scallops’ hemolymph, observing growth rate lengths of 0.058±0.174 mm/day in October, 0.003±0.024 mm/day in November, and 0.022±0.026 mm/day in December. Correspondingly, the growth rate weights slightly decreased from 0.022±0.107 g/day in October to 0.003±0.043 g/day in November and 0.008±0.037 g/day in December. Additionally, the total hemocyte count increased significantly over time, peaking in December at 25.846±7.251×10*6 cells/mL. These findings suggest that optimizing environmental conditions, particularly maintaining a temperature around 15°C and ensuring high food quality, can enhance the shell growth and survival rates of queen scallops in captivity. This research identifies key opportunities to improve the culture practices for A. opercularis, contributing to more sustainable aquaculture methods. [ABSTRACT FROM AUTHOR]

This study aims to develop an alternative aquafeed derived from insect meal for Lates calcarifer juveniles, with the objectives of exploring the physiological performance, biological parameters, and economic analysis of substituting fishmeal (FM) with defatted black soldier fly (Hermetia illucens) larvae (BSFL) as part of the diet of L. calcarifer juveniles. Five practical diets were formulated to include 0% (BSFL0, serves as control group), 5% (BSFL5), 10% (BSFL10), 15% (BSFL15), and 20% (BSFL20) of BSFL meal, partially or fully replacing FM, respectively. Each diet was randomly assigned to triplicate groups of 30 fish (10.70 ± 0.07 g) per tank (300 L). The fish were fed twice daily to apparent satiation. A 56‐day feeding trial was conducted to evaluate the impacts of defatted BSFL meal replacing FM on the growth performance, feed efficiency, composition analysis of fish muscle, cumulative mortality rate challenged with Vibrio parahaemolyticus, and economic returns of L. calcarifer. These results show that differences in weight gain and specific growth rate among the different treatments were statistically significant (p < 0.05), except for the absence of significant variation (p < 0.05) between BSFL0 and BSFL5, and followed by BSFL10 > BSFL0 > BSFL5 > BSFL15 > BSFL20. However, the feed conversion ratio and protein efficiency ratio showed the opposite trend as above. Although the diets experienced a decline in crude protein content and an increase in crude fat content with the increasing proportion of BSFL substituting FM, the crude protein and fat content of fish muscle were only slightly influenced. It is worth mentioning that levels of nonessential amino acids, delicious amino acids, saturated fatty acids, omega‐6, omega‐9 in BSFL10 group all showed an increase compared with the control group. After a 7‐day challenge test with V. parahaemolyticus, the cumulative mortality rates of the BSFL5 and BSFL10 groups, respectively, dropped to 5.20%, 5.28% compared to the control group's 16.88%; however, the mortality rates of BSFL15 (34.67%) and BSFL20 (41.77%) groups were found to be significantly (p < 0.05) increased. From an economic perspective, the incidence cost for each experimental group showed a trend as BSFL10 < BSFL0 < BSFL5 < BSFL15 < BSFL20, whereas the profit index in each treatment exhibited the opposite trend as above. It was concluded that low (5%) or moderate (10%) levels of BSFL substituting FM in aquaculture feed could improve the physiological performances, disease resistance, and economic returns of L. calcarifer. However, excessive substitution (>15%) leads to a negative effect. From an economic point of view, 10% inclusion of BSFL in practical diets is recommended for L. calcarifer juveniles. [ABSTRACT FROM AUTHOR]

Herbal plants have gained enormous interest due to their immune, antioxidant, and antibacterial activities. The present study proposed that white poplar (Populus alba) leave extract (WPE) might provide a promising alternative to traditional antibiotics to treat Aeromonas veronii infection in Nile tilapia (Oreochromis niloticus). WPE showed an in vitro antibacterial activity [22 ± 0.45 mm inhibition zone, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 60 µg/mL] against A. veronii. For the in-vivo study, a factorial (2 × 2) design was used to investigate the therapeutic effects of WPE on the antioxidant/immune status and blood biochemical parameters of Nile tilapia challenged with A. veronii. One-hundred sixty fish (33 ± 1.5 g) were assigned into four experimental groups, each with four replicates (4 glass tanks/group, 40 fish/group, 10 fish/tank) for 10 days. In the first (1st) and 2nd groups, 0 and 1.5 mg/L WPE were applied in tank water, respectively, without fish being challenged. In the 3rd and 4th groups, 0 and 1.5 mg/L WPE were applied in tank water, respectively, with fish intraperitoneal inoculated with 0.2 mL of A. veronii (0.5 × 107 CFU). Aeromonas veronii infection significantly diminished the survivability, hepatic catalase, lysozyme activity, nitric oxide, immunoglobulin M, phagocytic %, total protein, albumin, and globulin. Moreover, a significant rise in the hepatic malondialdehyde, serum hepatorenal function indicators, cortisol, and glucose levels were consequences of A. veronii challenge. Interestingly, the interaction between bacterial challenge and WPE application increased the survivability, antioxidant activity, and immune responses and reduced ALT levels of fish treated with WPE during the bacterial challenge. The serum creatinine, cortisol, and glucose levels were decreased in fish treated with WPE during the infection but still higher than in the non-infected fish either treated or not treated with WPE. In conclusion, WPE (1.5 mg/L) can be used as an antibacterial substance in fish farming to alleviate the detrimental impacts of A. veronii infection by enhancing the antioxidant/immune status of the infected fish. These outcomes could help reduce antibiotic usage in fish farms, which is conducive to the sustainable development of aquaculture. HIGHLIGHTS: White poplar extract (WPE) had an in vitro antibacterial activity against Aeromonas veronii. Aeromonas veronii infection inhibited the antioxidant/immune functions of Nile tilapia. Aeromonas veronii infection altered the hepatorenal functions and biochemical parameters of Nile tilapia. WPE at a level of 1.5 mg/L displayed a therapeutic effect in Nile tilapia against A. veronii. [ABSTRACT FROM AUTHOR]

Simple Summary: The slipper lobster is being studied because it is valuable commercially and is a good candidate for intensive aquaculture. Recently, researchers successfully raised these lobsters in captivity using only formulated feeds. This study aimed to understand the protein needs of juvenile slipper lobsters to develop feeds that are both nutritious and cost-effective, ensuring sustainable and profitable aquaculture practices. The study found that higher protein levels in the feed increase the lobsters' growth performance and affect their body composition. It provides the first insights into the protein requirements of slipper lobsters and highlights that the most expensive high-protein feeds may not always be the best choice if the protein is not efficiently used for growth. Therefore, further research is needed to refine these feed formulations for optimal growth and nutrient utilization. The effect of different dietary protein levels on apparent feed intake, apparent digestibility, body composition, nutrient retention, and growth efficiency of juvenile slipper lobster (Thenus australiensis) were evaluated for 74 days. Three isoenergetic and isolipidic feeds were formulated with crude protein levels of 445, 490, and 551 g kg−1 DM, designated as P45, P50, and P55, respectively. Lobsters were fed one of these feeds in quadruplicate tanks, with eight lobsters (mean initial wet weight 6.1 ± 0.3 g) per tank in a recirculating seawater system at 27 °C. Increasing dietary protein levels significantly increased apparent feed intake, final dry weight, and daily weight gain. Dietary protein affected whole-body protein, lipid, and energy content. Lobsters fed P55 had significantly higher lipid and energy content than those fed P50 and P45. Protein content was significantly higher in lobsters fed P55 than P50, while P45 was not significantly different from either P50 or P55. Slipper lobsters grew best on a feed containing 550 g kg−1 crude protein (equivalent to 518 g kg−1 digestible protein), providing initial insights into their protein dietary requirement. This study established a foundation for developing standardized feeds, with further research needed to optimize growth performance and nutrient utilization. [ABSTRACT FROM AUTHOR]