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Freshwater bivalves are key faunal elements of aquatic ecosystems. Native species declines are paralleled by increasing distribution and abundances of non-native species. Appropriate management of both groups depends on knowledge of their interactions, which remains limited. Herein, we systematically review the current knowledge status of native and non-native bivalves in Europe, analyzing their functional interactions as well as niche and distribution overlaps between species. We also review existing management tools for non-native species in light of their applicability and sustainability. Strong and multiple interactions as well as niche overlaps between native and non-native bivalves already exist in Central Europe, especially with regard to Dreissena spp., Corbicula spp., and Sinanodonta woodiana. Direct competition is low with native species that have a high degree of specialization such as Margaritifera margaritifera, whereas the greatest niche overlap and competition occurs in generalist species such as Anadonta anatina, Unio pictorum, and S. woodiana. Early detection and preventive measures against undesired species are most successful in limiting their spread. Most methods for managing non-native species are unspecific and thus also include undesired side effects on endangered native species. The conservation and restoration of functionally intact bivalve habitats are the most sustainable and most resilient ways of management. [ABSTRACT FROM AUTHOR]

Behaviour is a fundamental parameter for understanding the animal fitness, serving as an indicator of exposure to stressors. In ecosystems, animals often face multiple stressors simultaneously. Their behavioural responses may vary when exposed to individual stressors, whilst synergistic, additive, or antagonistic effects can result from the interaction of multiple stressors. Therefore, it is imperative to conduct studies that take into account the common occurrence of multi-stress scenarios in aquatic ecosystems. We tested the effects of three sources of stress (acidity (A), toxicity with acetone (T) and conspecific chemical cues (S)) on the behaviour of the aquatic snail Potamopyrgus antipodarum (Tateidae, Mollusca). We evaluated the impact of each stressor, as well as in combinations of two or three stressors simultaneously. The highest time to initiate movement was shown by the animals of the low water pH (A) followed by those exposed to the combination of low water pH and acetone exposure (AT). The differences between the time to initiate movement of each treatment with control revealed a marked decrease in the differences for the snails from the conspecific chemical cues (S) and ST treatments, which mean a higher time to initiate movements. It is concluded that behaviour varied depending on the source and combination of stress. While an acid environment and conspecific signals had contrasting effects when applied separately, their simultaneous exposure resulted in no significant impact. This highlights the importance of considering the combined effects of multiple stressors when extrapolating laboratory results to real-world scenarios, where organisms are often exposed to more than one stressor at a time. [ABSTRACT FROM AUTHOR]

Background: As recent evidence shows the prevalence and transmission of Aeromonas species in Southwest Asia, and there is no updated information on the characteristics of Aeromonas in Iran, we conducted this review. We systematically searched biomedical databases (PubMed, Web of Sciences, Scopus, SID, ISC, and Google Scholar) to identify relevant studies investigating the prevalence, antibiotic resistance, and main reservoirs of Aeromonas in aquatic animals and human clinical specimens during 2000–2023 in Iran. Cochrane's Q test and I^2 statistical test was used to assess heterogeneity, and publication bias was assessed using funnel plots and random effects tests. Results: In Iran, among 8347 human clinical samples and 1802 animal and food samples, only 87 (1.04%) and 388 (21.53%) samples were positive for Aeromonas spp. respectively, and the most isolated species was A. hydrophila. The main reservoir for Aeromonas spp. were twenty-four genera of aquatic animals besides minced meat, pigeon stool and chicken meat. In Iran, Aeromonas spp. isolates showed maximum resistance to ampicillin, tetracycline, nalidixic acid and vancomycin. The heterogeneity test for prevalence of Aeromonas species on human samples and animals or food products was significant (88.1256, (5), P-value < 0.0001) and the heterogeneity rate was 97.34% with a confidence interval of 0.2–4.3 and (194.02, (10), P-value < 0.0001) and the heterogeneity rate was 94.85% with a confidence interval of 15,124 − 33,335 respectively. Conclusions: According to these results, it is essential for exclusive attention to the prevalence and antibiotic resistance of Aeromonas in different provinces of Iran. Furthermore, special planning should be done for prevention, outbreak control and proper treatment of infections in the aquaculture industry and human societies. [ABSTRACT FROM AUTHOR]

Predators have important functional roles in coastal ecosystems. In cases where such species are locally depleted or extirpated, a proactive restoration strategy may include conservation translocation. This study reports on such translocations of Atlantic wolffish (Anarhichas lupus) to fjord habitats in northern Norway where the species is currently severely depleted. A total of 20 pioneer individuals measuring 42–80 cm in length were captured in outer coastal habitats and subsequently tagged, released, and tracked within a fjord using acoustic telemetry. A first group of seven individuals were monitored for 14 months during 2017 and 2018, while a second group of 13 individuals were monitored for 4 months during 2019. Up to 40% of translocated wolffish remained inside their new fjord environment until the study was terminated, while the remaining 60% likely dispersed. Weekly home range size decreased substantially with time for larger fish, while this trend was weaker for smaller fish. Our study implies that there is reason for cautious optimism regarding the implementation of conservation translocation of wolffish in coastal ecosystems, while acknowledging the challenge of accounting for animal dispersal in aquatic systems. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are ubiquitous environmental contaminants, and amphibians are especially susceptible owing to their dual aquatic and terrestrial life cycle and permeable integument. This research examines the presence, composition, and potential origins of microplastics in tadpoles, adult frogs, and their environments in different regions of Türkiye, concentrating on three Anatolian water frog species: Pelophylax ridibundus, P. bedriagae, and P. caralitanus. Samples were obtained from 11 sites, encompassing water bodies, sediments, tadpoles, and the gastrointestinal tracts (GITs) of adult frogs. MPs were examined for polymer type, morphology, and dimensions via stereomicroscopy and Fourier transforms infrared spectroscopy. Results indicated that microplastics were absent in 64% of sediment and water samples; nevertheless, elevated quantities were identified in areas with considerable human activity, such as İstanbul. Tadpoles demonstrated negligible MP intake, with merely 2 MPs identified among 157 samples, resulting in an average of 0.01 MP per individual. Conversely, 44% of the 100 adult frogs exhibited microplastics in their gastrointestinal tracts, averaging 1.52 microplastics per individual. The MPs were primarily fibers (90.8%) and comprised polymers such as ethylene–vinyl acetate (EVA) (32.5%) and polycyclohexylenedimethylene terephthalate (PCT) (20.8%). The study emphasizes the potential dangers of microplastics to amphibian health and reinforces the necessity of addressing microplastic pollution in freshwater habitats through focused conservation initiatives. [ABSTRACT FROM AUTHOR]

Polyphenols are a diverse group of naturally occurring bioactive compounds in plants that have attracted considerable interest due to their potential antiviral properties. Polyphenols primarily exert their antiviral effect by specifically targeting the viral replication. This review examines the role of polyphenols as potential antiviral agents with a focus on their structure, mechanism of action, and bioavailability. Different polyphenols, their origin, and documented effects on viral pathogens that impact the health of finfish are also discussed. The focus has been on the experimental studies conducted on the antiviral activity of polyphenols against fish viruses. Various studies on polyphenols such as such as flavanols, flavonoids, and phenolic acids have revealed their potential antiviral properties in aquaculture, whereas some polyphenolic compounds also exhibit anti-cancer, neuroprotective, and anti-inflammatory properties. Studies on polyphenolic compounds like coumarin and its derivatives have shown potential antiviral effect against OIE-reported fish viruses like IHNV, VHSV, and SVCV. However, there still remains a critical gap in understanding and exploring the long-term impact of polyphenols on fish health and their effectiveness as potent antiviral agents. Targeted research on these compounds will allow for the development of effective antiviral strategies in aquaculture. Thus, continuous exploration of these natural antiviral agents holds a great potential for enhancing the health status of fishes in aquaculture. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of dietary protein source (DPS) and extrusion temperature (ET) on the physical qualities of extruded grass carp feed and the growth performance, tissue composition, and gut microbiota of these animals. We used a 2 × 2 factorial experimental design, with DPSs consisting of mostly plant or fishmeal proteins extruded at 120 °C (DP1 and DA1 diets) or 140 °C (DP2 and DA2 diets) for grass carp. The growth trial was performed for 9 weeks, and the gut microbiota trial lasted 4 weeks. Compared with the fishmeal-based diets, the plant protein-based diets produced higher expansion ratios (P < 0.001). A high ET also improved the expansion ratio (P < 0.001) and significantly decreased the feed pellet bulk density (P < 0.001). The DP2 diet had the highest hardness and water solubility index and the lowest water absorption index. The DP1 diet exhibited the lowest protein and phosphorus apparent digestibility coefficients (ADCs). The ET significantly affected the ADCs for the plant protein-based diets, but not for the fishmeal-based diets. Grass carp fed the DP1 diet presented the lowest weight gain and specific growth ratio. The interactions between DPS and ET affected the final body weight (P = 0.030), protein efficiency ratio (P = 0.011), and feed efficiency (P = 0.016), and these indices were significantly greater in grass carp fed the DP2 diet than in those fed the DP1 diet. However, DPS and ET did not affect the concentrations of crude protein or amino acids in the dorsal muscle. Compared with grass carp fed plant-based diets, those fed fishmeal-based diets presented greater fat contents in the muscle (P = 0.011) and liver P = 0.037), and a greater hepatosomatic index (P = 0.003). The interaction of DPS and ET influenced the viscerosomatic index (VSI, P = 0.001), with the highest VSI found after feeding the DA2 diet. DPS (P = 0.001) but not ET (P = 0.172) significantly affected the gut microbial communities, although the plant protein-based diets with increased ET resulted in more differential taxa and greater differences in the abundances of the core microbiota in grass carp compared to the fishmeal-based diets. These results indicate that improving the ET of plant protein-based diets can alter the physical qualities of the diets, further affecting the gut microbiota, and enhancing the growth performance of grass carp. These findings reveal that higher ETs are needed for plant protein-based diets than for fishmeal-based diets, which is a valuable guideline for feed production. [ABSTRACT FROM AUTHOR]

Nanoplastic (NP) pollution poses serious health hazards to aquatic ecosystems, impacting various physiological systems of aquatic organisms. This review examines the complex interplay between NPs and different physiological systems. In the digestive system, NPs downregulate the hsp70-like gene in Mytilus galloprovincialis, leading to decreased metabolic processes and impaired digestion. Neural system exposure to NPs induces abnormal expression of genes like neurogenin1, GFAP, FBJ murine osteosarcoma viral oncogene, GAP-43, synapsin IIa, apoptosis regulator a, Bcl2 and Caspase a, and apoptosis-related cysteine peptidase. These genes play a crucial role in neurodevelopment, synaptic function and apoptosis regulation, potentially impacting neurobiology and cancer biology. NPs also affect reproduction, including gametogenesis, spawning, fertilization, embryogenesis and larval survivability. In the respiratory system, treatment with these causes inflammation in the lungs and gills, resulting in respiratory dysfunction. Moreover, this review investigates the complex interaction between NPs and the immune systems of both invertebrates (e.g., molluscs, arthropods, echinoderms) and vertebrates (e.g., zebrafish). NPs-induced alterations in immune cell function heightened the susceptibility to pathogens and disrupted immune signalling pathways. Subcellular inflammatory responses have been characterized by the secretion of inflammation-promoting and chemotactic cytokines such as irg1l, interleukin 1, interferon, interleukin 6, C–C motif chemokine ligand 20a and tumour necrosis factor. The assessment of the combined effects of NPs and other xenobiotics highlighted their possible synergistic impacts on aquatic fauna and the environment. This comprehensive review emphasizes the urgent need for further research to understand the cumulative effects of NPs on organism health and fitness across multiple physiological systems. [ABSTRACT FROM AUTHOR]

Aeromonas sobria is an opportunistic pathogen that can infect humans, animals and aquatic species, which is widely distributed in different aquatic environments and products. In recent years, with the rapid expansion of intensive aquaculture, the disease caused by A. sobria has occurred. This study aims to understand the pathogenic characteristics of A. sobria and provide scientific basis for the prevention and control of the epidemic. The dominant strain As012 was isolated from the diseased rainbow trout during the outbreak. Through physiological and biochemical experiments, sequencing and phylogenetic tree analysis of 16S rRNA and gyrB genes, the strain As012 was identified as A. sobria. The clinical signs of the diseased rainbow trout in the experimental infection were consistent with those in the farm, and the LD50 was 1.0 × 106.6 CFU/mL. The histopathological lesions in the gills, heart, liver, spleen and intestines were mainly extensive hemorrhage. In addition, eight virulence genes were screened from strain As012, including Act, Aer, AexT4, Alt, ahyB, ascV, Nuc and Hly. The strain As012 can grow in the environment with pH 1–11, temperature 8–43°C and NaCl concentration 0–8%. The drug sensitivity results showed that it was resistant to 12 antibiotics including penicillin G, vancomycin, and clindamycin, and highly sensitive to 16 antibiotics including cefazolin, ciprofloxacin, and furadantin. The results showed that A. sobria , the dominant strain isolated from diseased rainbow trout, was the main pathogen causing the epidemic in the farm. The strain As012 has a very wide range of growth and strong pathogenicity, causing widespread hemorrhaging in various tissues of rainbow trout. It is multi-resistant, but highly sensitive to cephalosporins, quinolones, nitrofurans and sulfonamides. Among them, ciprofloxacin will be one of the effective antibiotics for preventing and controlling A. sobria infection in Chinese aquaculture. [ABSTRACT FROM AUTHOR]

Small RNAs (sRNAs) are a class of molecules capable of perceiving environmental changes and exerting posttranscriptional regulation over target gene expression, thereby influencing bacterial virulence and host immune responses. Pseudomonas plecoglossicida is a pathogenic bacterium that poses a significant threat to aquatic animal health. However, the regulatory mechanisms of sRNAs in P. plecoglossicida remain unclear. This study focused on sRNA113, previously identified as a potential regulator of the fliP gene, a key component of the lateral flagellar type III secretion system. To investigate the effects of sRNA113 on P. plecoglossicida virulence, as well as its role in regulating pathogenic processes and host immune responses, mutant strains lacking this sRNA were generated and analyzed. Deletion of sRNA113 resulted in the up-regulation of lateral flagellar type III secretion system-related genes in P. plecoglossicida, which enhanced bacterial swarming motility, biofilm formation, and chemotaxis ability in vitro. In vivo infection experiments with pearl gentian grouper revealed that sRNA113 deletion enhanced the pathogenicity of P. plecoglossicida. This heightened virulence was attributed to the up-regulation of genes associated with the lateral flagellar type III secretion system, resulting in higher bacterial loads within host tissues. This amplification of pathogenic activity intensified tissue damage, disrupted immune responses, and impaired the ability of the host to clear infection, ultimately leading to mortality. These findings underscore the critical role of sRNA113 in regulating the virulence of P. plecoglossicida and its interaction with host immune defenses. This study provides a foundation for further exploration of sRNAmediated mechanisms in bacterial pathogenesis and hostpathogen interactions, contributing to a deeper understanding of virulence regulation and immune evasion in aquatic pathogens. [ABSTRACT FROM AUTHOR]

Simple Summary: Aeromonas hydrophila and Aeromonas veronii are common pathogenic bacteria in grass carp aquaculture. Through comprehensive histopathological analysis and molecular characterization, we found that both pathogens caused severe cellular necrosis, cytoplasmic vacuolization, and hemorrhage in the liver of grass carp, similar to the manifestations of infection in other aquatic animals. The grass carp showed complex regulation of immune and metabolic responses during infection, especially activation of Toll-like receptors and TNF signaling pathways. Our findings provide new insights into host–pathogen interactions during Aeromonas co-infection in grass carp and provide a scientific basis for the development of prevention and control strategies. The grass carp (Ctenopharyngodon idella) is highly susceptible to infections caused by Aeromonas species, particularly A. hydrophila and A. veronii. However, the immunological mechanisms underlying co-infection by these pathogens remain largely uncharted. This study investigated the pathogenesis and host immune response in grass carp following concurrent infection with A. hydrophila and A. veronii. Mortality was observed as early as 24 h post-infection, with cumulative mortality reaching 68%. Quantitative analysis demonstrated significantly elevated bacterial loads in hepatic tissue at 3 days post-infection (dpi). Histopathological evaluation revealed severe hepatic lesions characterized by cellular necrosis, cytoplasmic vacuolization, and hemorrhagic manifestations. Comparative transcriptomic analysis of hepatic tissues between co-infected and control specimens identified 868 and 411 differentially expressed genes (DEGs) at 1 and 5 dpi, respectively. Gene ontology and KEGG pathway analyses revealed significant enrichment of immune-related genes primarily associated with Toll-like receptor signaling and TNF signaling cascades. Notably, metabolic pathways showed substantial suppression while immune responses were significantly activated after infected. These findings provide novel insights into the host–pathogen interactions during Aeromonas co-infection in grass carp, which may facilitate the development of effective prevention and control strategies. [ABSTRACT FROM AUTHOR]

The invention of plastics has brought great convenience to the daily life of humans. However, due to the lack of an efficient recycling mechanism, a large number of plastic products have entered the freshwater environment, resulting in the pollution of microplastics (MPs), which poses a serious threat to aquatic and terrestrial organisms. Therefore, this paper reviews the toxic effects of MPs on algae and aquatic animals in freshwater environments and human health. This study aims to summarize the influencing factors and mechanisms of the toxic effects of MPs on freshwater environments. This study is of great significance for the effective prevention and control of MPs pollution and to enhance the quality of freshwater environments. [ABSTRACT FROM AUTHOR]

ABSTRACT Potentially zoonotic Mycobacterium spp. are impacting freshwater ornamental fish in Trinidad and Tobago. Clinical cases presented at the Aquatic Animal Health Unit of The University of the West Indies, School of Veterinary Medicine, from September 2011 to September 2018 indicated the presence of piscine mycobacteriosis in freshwater ornamental fish from locations throughout Trinidad and Tobago. Subsequently, an investigation was conducted from June 2018 to December 2021 to identify the specific Mycobacterium spp. involved. Nested polymerase chain reaction (PCR) was used to amplify and later sequence the 723 bp of the rpoB. Analysis of region V of the rpoB offers similar discriminatory power as concatenation or whole genome analysis of Mycobacterium spp., and serves as an acceptable method for differentiating and discriminating between species in this genus. With respect to tank‐reared freshwater ornamental fish, this study identified M. fortuitum (98.8% identity), M. liflandii (100% identity), M. stomatepiae (97.2% identity), M. pseudoshottsii related (96.9% identity), two M. stomatepiae related (95.4% and 96.7% identity), M. immunogenum related (93.4% identity), and 17 M. insubricum related (91.4%–95.2% identity). Additionally, seven mycobacteria related to M. insubricum were identified in wild‐caught guppies. These findings suggest that both known, and potentially novel Mycobacterium spp. are circulating, and adversely impacting the local populations of freshwater ornamental fish in Trinidad and Tobago. [ABSTRACT FROM AUTHOR]

Arachidonic acid (AA) is an important long-chain polyunsaturated fatty acid in animals and a necessary nutrient for aquatic animals. AA is primarily concentrated in cell membranes and exerts its effects through three key metabolic pathways within living organisms. AA is involved in a variety of physiological processes in aquatic animals, including growth and survival, reproduction, tissue development, enhancement of sperm and egg vitality, improvement of seedling quality, modulation of immune responses, enhancement of stress resistance, and promotion of skeletal development, thereby improving the overall quality of aquatic animals. The article mainly introduces the synthesis and metabolic mechanisms of AA within living organisms, summarizes the effects of adding AA to feed on the growth, survival, tissue development, immunity, and stress resistance of fish, crustaceans, and other aquatic animals in recent years, and provides a reference for the further development and utilization of AA. [ABSTRACT FROM AUTHOR]

Researchers have been inspired to study the mechanics of aquatic animals to develop advanced underwater vehicles and robots, as they demonstrate swimming abilities that are far superior to those of human-made propulsion devices. Autonomous underwater vehicles (AUVs) designed for military, scientific, and environmental applications often require efficient propulsion near boundaries, motivating the study of boundary effect in swimming organisms. This research investigates the hydrodynamic characteristics of wall effects in undulating hydrofoils, exploring variations in undulation wavelength (λ), Strouhal number (St), wall clearance (h/c), and Reynolds number (Re). Our current work aims to elucidate how these parameters influence lift coefficient, drag coefficient, power consumption, and swimming efficiency compared to the free-stream conditions. We have explained how the kinematics of the undulating hydrofoils affect the direction of forces over their different locations and result in variations of lift and drag with the kinematic parameters. We have also explored the interaction of vortices shed from the trailing edge and their influences on the flow characteristics in swimmers near boundaries. Comparative analyses with rigid pitching hydrofoils highlight distinct hydrodynamic behaviors in undulatory motion, emphasizing the importance of flexibility and kinematic adjustments near boundaries. The wall effect increases viscous drag across the parameters explored in this study. Pressure thrust is appreciably enhanced at higher values of (St) and (λ). However, while the amplitude of lift increases monotonically with the wall clearance ratio for all λ, the time-averaged lift departs from a monotonic trend with clearance at lower λ ranges. Swimming power consumption increases near boundaries, but swimming efficiency decreases with lower wall clearance in moderate Reynolds number scenarios. [ABSTRACT FROM AUTHOR]

For many, there exists a cognitive inconsistency between the practice of eating non-human animals and the belief that animals are morally relevant. This juxtaposition has fittingly been described as the 'meat paradox'. However, what can be said about the decision to eat only the flesh of fish? The present research seeks to understand what attitudes lead pescetarians to remove terrestrial animals from their plate but still include aquatic animals such as fish. Semi-structured interviews were conducted with self-identifying pescetarians and analysed using reflexive thematic analysis. Three themes are presented which can be understood by reference to the construal-level theory of psychological distance. Fish were perceived as distant on multiple dimensions which resulted in speciesist (the idea that some species are more important and morally relevant than others) attitudes toward marine animals' capabilities and the justification of pescetarianism as a compromise between debates of feasibility and ethical desirability. [ABSTRACT FROM AUTHOR]

The invasion and spread of aquatic animal diseases from abroad reduces fisheries and aquaculture production and causes food security issues. If infection spreads to natural populations, it can also cause environmental issues. One measure to reduce such risks is the use of domestic seeds for aquaculture. This study aims to identify consumer preferences for domestic aquaculture seeds (juvenile shrimp) and how these preferences vary depending on what information is provided and on consumer sociodemographic characteristics. A discrete choice experiment was used in this study, and the results showed the following: (1) on average, environmental and food security information had no effect; (2) consumers responded more to the information the older they were, but this tended to weaken when they received both environmental and food security information; and (3) men and women responded contrastingly to food security information. Therefore, when providing consumers with information on aquatic animal diseases, it is necessary to consider the content and volume of the information depending on the gender and age of the target consumer group. [ABSTRACT FROM AUTHOR]

High levels of heavy metals in the environment pose a significant risk to the aquatic ecosystem and its organisms. The non-biodegradable nature and lengthy persistence of heavy metals in the environment lead to toxicity in shrimp. Using aquatic animals as bio-indicators of metal contamination provides valuable data on acute and chronic toxicity in aquatic species and environmental quality. This review aims to provide insights into the sources, impacts, diseases and mitigation strategies related to heavy metal pollution in shrimp farming and the dangers to humans. Shrimp growth and development at each stage exhibit distinct responses to toxicity, which can vary depending on the species, types of metals, their mechanisms of action, as well as the concentration of heavy metals and duration of exposure. While several heavy metals are considered essential nutrient elements that enhance shrimp growth and feed efficiency, exceeding the maximum tolerable limit threatens shrimp health, human consumers, and ecological systems' stability. Shrimp species subjected to lethal toxic metal concentrations experience significant effects on accumulation in histopathology. Heavy metal toxicity has been linked to high mortality rates, malformation rates, oxidative stress, moulting issues, and decreased reproduction with increasing concentrations in shrimp. Various methods have been reported for removing heavy metal ions from aquatic environments, including filtration, adsorbents, removal efficacy, operating conditions, and the pros and cons of each technique. Therefore, this review provides an overview of how heavy metals can affect shrimp physiology and dangers to consumers. It aims to increase awareness about the importance of preventing and regulating their contamination in aquatic environments. [ABSTRACT FROM AUTHOR]

The responses of assemblages and ecosystems to river intermittency are often considered on large spatial scales, such as those associated with the Köppen climate classification. However, river intermittency may naturally occur even in humid regions, and the effects may differ from those where intermittency occurs throughout the area. This study aimed to examine the differences in taxonomic and trait composition of aquatic insects between intermittent rivers in the Seto Inland Sea watersheds and neighboring humid-temperate rivers in Japan using national census data. While the climate in the most part of the Japanese Archipelago is categorized as humid-temperate, and rivers are usually perennial, local climate in the Seto Inland Sea watersheds has low summer precipitation compared with that in neighboring regions, thereby resulting in river intermittency. Consistent with the previous studies in the regions where rivers are intermittent on a large spatial scale, we observed that aquatic insects with multivoltinism and/or aerial respiration notably tolerated river intermittency. In contrast, the aquatic insect fauna in Japanese intermittent rivers represented subsets of those in the humid-temperate rivers, although previous studies such in Mediterranean regions have reported high endemism and species diversity in intermittent rivers. These results highlight the importance of exploring the role of river intermittency on small to medium spatial scales, as well as on large scales, to project effects of ongoing and future climate changes on species diversity. [ABSTRACT FROM AUTHOR]

Phytosterols are a class of natural alcohol compounds with cyclopentane-perhydrophenanthrene as the skeleton. Its structure is similar to cholesterol/sterol, and it usually exists on plant cell membranes in the form of free state, esterified state and glycoside. Because of its cholesterol-lowering, anti-oxidation, prevention of cardiovascular disease and other physiological functions, it has been widely concerned in medicine and, livestock and poultry animals research in recent years. phytosterols have been widely used in the feed and medicine of livestock and poultry animals, and have shown good application effects in promoting growth, improving physiological metabolism, and regulating immunity. There are obvious differences in physiological metabolism between aquatic animals and livestock and poultry animals. At present, the research reports of phytosterols in aquatic animals are very scarce. In this review, the structure and function of phytosterols, the level of phytosterols in some feed raw materials and the detection methods of phytosterols were reviewed, and the application of phytosterols in aquatic animal feeds such as fish and aquatic crustaceans were summarized. Under the current policy background of green and healthy aquaculture proposed by the state, the development of phytosterols into green and safe aquatic feed additives has far-reaching significance for the healthy development of aquaculture. It is of far-reaching significance to develop phytosterols into green and safe aquatic feed additive products to realize the green development of aquaculture industry. [ABSTRACT FROM AUTHOR]

Simple Summary: Viperin, as an important ISG, has important roles in antiviral immunity. In this paper, the common carp viperin (cc-viperin) gene is characterized and analyzed. The cc-viperin gene's nucleotide and amino acid sequence alignment reveals that cc-viperin displays relatively high sequence identity compared with other species. It is located in cytoplasm. It is expressed in most tissues. It could inhibit spring viremia of carp virus (SVCV) replication in EPC cells, showing an antiviral effect of viprein. This research is not only an extension of viperin gene research but also contributes to basic research on viral diseases in aquatic animals. Viperin is an interferon-stimulated gene (ISG) that plays an important role in the congenital antiviral immunity of vertebrates. In this study, the common carp viperin (cc-viperin) gene is characterized, and we determine whether it has the ability to inhibit spring viremia of carp virus (SVCV) replication in EPC cells. The results showed that the full-length cDNA of the cc-viperin gene was 1044 bp and it encoded 348 amino acids. The cc-viperin sequence contained a leucine zipper in the N-terminal, a CxxxCxxC motif in the SAM domain, and a conservative C-terminus. The cc-viperin gene's nucleotide and amino acid sequence alignment revealed that cc-viperin displayed relatively high sequence identity compared with other species. Phylogenetic analysis displayed the close relation of cc-viperin with Carassius auratus and Mylopharyngodon piceus. Subcellular localization analysis indicated that the cc-viperin protein was located in the cytoplasm. The gene expression results showed that cc-viperin was expressed in all of the tissues tested. Its expression level significantly increased in EPC cells after 24 h to 72 h compared to the control during SVCV infection. Moreover, cc-viperin significantly inhibited SVCV replication when it was overexpressed, whereas it increased SVCV replication when it had reduced expression in EPC cells, respectively. To summarize, the results obtained in this work show that cc-viperin shares similar sequence characteristics with other vertebrates, and it could inhibit SVCV replication in EPC cells, displaying an antiviral effect in common carp. [ABSTRACT FROM AUTHOR]

Objective: This study evaluated the influence of melatonin supplementation on tissue's response of endodontic sealers in Wistar rats. Methodology: Forty-eight rats received subcutaneous implants of four polyethylene tubes: one empty (control) and three filled with endodontic sealers (AH Plus, Endofill and Sealapex). Half of the animals were supplemented with melatonin (ME) and the remaining treated with water (WA) for 15 days before the implantation until euthanasia, forming the groups: control-WA, AH Plus-WA, Endofill-WA, Sealapex-WA, Control-ME, AH Plus-ME, Endofill-ME and Sealapex-ME. After 5, 15 and 30 days, (n = 8) tubes were removed and evaluated in H&E., immunohistochemistry, PSR, VK and POL. The results were statistically analyzed (p < 0.05). Results: In animals treated with water, Endofill-WA evoked more intense inflammatory infiltrate compared to AH Plus-WA and Control-WA in a 30-day period (p < 0.05). In animals supplemented with melatonin, there was any difference among endodontic sealers' response in any period of analysis (p > 0.05). Comparing the individual response of each sealer, over a 30-day period, Endofill-ME and Sealapex-ME showed less inflammatory infiltrate compared to Endofill-WA and Sealapex-WA, respectively (p < 0.05). Immunostaining for IL-6 and TNF-α was less intense for all groups in animals supplemented with melatonin, in most periods, except for the Endofill sealer (p < 0.05). Furthermore, Endofill-ME at 5 days and AH-Plus-ME at 30 days showed a higher percentage of mature collagen fibers compared to the Endofill-WA and AH Plus-WA, respectively (p < 0.05). Positive structures for von Kossa staining and birefringent to polarized light were observed only for Sealapex-WA and Sealapex-ME in all periods. Conclusions: It can be concluded that melatonin influences the tissue response to endodontic sealers, modulating the inflammatory and reparative process. [ABSTRACT FROM AUTHOR]

Yessotoxin (YTX) is a disulfated toxin produced by harmful dinoflagellates and causes risks to aquatic animals. Polystyrene (PS) microplastics could absorb toxins in seawaters but pose threats to organism growth. In this study, the combined toxic effects of YTX (0, 20, 50, and 100 µg L−1) and PS (0, 5, and 10 µg mL−1) on the survival, reproduction, and population growth of marine rotifer Brachionus plicatilis at 20 °C, 25 °C, and 30 °C were evaluated. Results indicated that the survival time (S), time to first batch of eggs (Ft), total offspring per rotifer (Ot), generational time (T0), net reproduction rate (R0), intrinsic growth rate (rm), and population growth rate (r) of rotifers were inhibited by YTX and PS at 25 °C and 30 °C. Low temperature (20 °C) improved the life-table parameters T0, R0, and rm at YTX concentrations less than 100 µg L−1. Temperature, YTX, and PS had interactive effects on rotifers' S, Ft, Ot, T0, R0, rm, and r. The combined negative effects of YTX and PS on rotifers' survival, reproduction, and population growth were significantly enhanced at 30 °C. These findings emphasized the importance of environmental temperature in studying the interactive effects of microplastics and toxins on the population growth of zooplankton in eutrophic seawaters. [ABSTRACT FROM AUTHOR]

Hypochlorous acid has been attempted as an additive to animal drinking water in practical animal farming processes for water microbial quality control. Despite its potential, there is still a knowledge gap concerning the effects of hypochlorous acid on both poultry growth performance and gut microbial load. To address this gap, an animal study was conducted using flow cytometry to quantify the age-related microbial load in broiler manure and gut contents. We observed that the effect on growth performance was sustained only during the starter phase, with no significant impact throughout the entire production cycle. The treatment could reduce the microbial load of both fresh broiler manure and cecal contents. Despite this convergence in the duodenum, significant differences in microbial loads between the control and treatment groups persisted in the manure and cecal contents throughout the later stages. Our findings demonstrate that consuming low-concentration hypochlorous acid water over the long term can lower the microbial load in the broiler gut throughout the entire growth cycle without impacting overall growth performance. Future research on drinking or feed additives should incorporate microbial absolute quantification methods to achieve a more precise assessment of microbiota. [ABSTRACT FROM AUTHOR]

Aquaculture, a cornerstone of global food production, confronts myriad challenges including disease outbreaks and environmental degradation. Achieving nutritionally balanced aquafeed is critical for sustainable production, prompting exploration into innovative solutions like selenium nanoparticles (SeNPs). SeNPs offer potent antimicrobial, antioxidant, and growth-promoting properties, bolstering gut immunity and digestive capacity in aquatic animals. Their high bioavailability and ability to traverse gut barriers make them promising candidates for aquafeed supplementation. This study investigates SeNPs as a cutting-edge solution to enhance nutrient supply in aquaculture, addressing key challenges while promoting environmental stewardship and food security. By synthesizing current research and highlighting future directions, this review provides valuable insights into sustainable aquaculture practices. SeNPs hold promise for revolutionizing aquaculture feed formulations, offering a pathway to improved production outcomes and environmental sustainability. [ABSTRACT FROM AUTHOR]

Abstract Microplastics (MPs) are ubiquitous environmental contaminants, and amphibians are especially susceptible owing to their dual aquatic and terrestrial life cycle and permeable integument. This research examines the presence, composition, and potential origins of microplastics in tadpoles, adult frogs, and their environments in different regions of Türkiye, concentrating on three Anatolian water frog species: Pelophylax ridibundus, P. bedriagae, and P. caralitanus. Samples were obtained from 11 sites, encompassing water bodies, sediments, tadpoles, and the gastrointestinal tracts (GITs) of adult frogs. MPs were examined for polymer type, morphology, and dimensions via stereomicroscopy and Fourier transforms infrared spectroscopy. Results indicated that microplastics were absent in 64% of sediment and water samples; nevertheless, elevated quantities were identified in areas with considerable human activity, such as İstanbul. Tadpoles demonstrated negligible MP intake, with merely 2 MPs identified among 157 samples, resulting in an average of 0.01 MP per individual. Conversely, 44% of the 100 adult frogs exhibited microplastics in their gastrointestinal tracts, averaging 1.52 microplastics per individual. The MPs were primarily fibers (90.8%) and comprised polymers such as ethylene–vinyl acetate (EVA) (32.5%) and polycyclohexylenedimethylene terephthalate (PCT) (20.8%). The study emphasizes the potential dangers of microplastics to amphibian health and reinforces the necessity of addressing microplastic pollution in freshwater habitats through focused conservation initiatives.

With the development of China's economic level and improving people's living standards, the state's supervision of food health and safety has increased. Consumer demand for many people has gradually changed from being satiated to eating well, and high-quality, environmentally friendly, and healthy aquatic products have become increasingly popular with consumers. However, intensive and high-density aquaculture causes the deterioration of water environmental conditions, the increase of anti-nutrient factors and nutritional imbalance caused by the replacement of animal protein with plant protein in feed, and changes in the growth, immunity, and digestive ability of aquatic animals caused by changes in feed nutrients, traditional processing methods, and transportation stress. The above situations encountered in aquaculture have a common impact on aquatic animals and inevitably cause a reduction in the muscle quality of aquatic animals. Therefore, improving the muscle quality of aquatic animals and the quality of aquatic products is an urgent problem with significant research value and potential.To improve aquatic quality, first, it is necessary to first identify the indicators of muscle quality in aquatic animals to improve aquatic quality. However, there is still a lack of a systematic muscle quality evaluation index system in the current aquaculture research. Therefore, this study reviewed the evaluation indices of muscle quality, including meat content, muscle nutrient composition, muscle fiber structure, muscle texture characteristics, and muscle physicochemical indices, to provide a reference for establishing scientific muscle quality evaluation indices. In addition, factors affecting muscle quality must be considered in studies aimed at improving the muscle quality of aquatic animals. Only by understanding the factors affecting muscle quality in aquatic animals can the key factors regulating muscle quality and their mechanisms be studied more comprehensively and scientifically. This study reviewed the factors affecting the muscle quality of aquatic animals, including feed nutrients, feed additives, and the culturing environment, and found that nutrients are key factors in improving the muscle quality of aquatic animals.Protein is an important nutrient, the main component of muscle, and an important indicator of muscle quality. Amino acids are the basic units of proteins and have a vital impact on muscle quality and flavor. Therefore, it is important to study the effects and mechanisms of action of amino acids on muscle quality in aquatic animals. Therefore, the effects of dietary amino acids on the muscle quality of aquatic animals were reviewed in this study, including the effects of amino acids on muscle nutrients, flavor, texture indices, and physical and chemical properties of aquatic animals. Furthermore, the effects of amino acids on muscle quality, including the promotion of protein synthesis, regulation of fat deposition, enhancement of antioxidant activity, and maintenance of intestinal health, were reviewed.In summary, this study summarized the influence of amino acids on the muscle quality of aquatic animals and its mechanism from the aspects of muscle quality evaluation indices, factors affecting meat quality, and the influence of amino acids on muscle quality, providing a reference for further research on the regulation of muscle quality by amino acids and the improvement of feed nutrients on the meat quality of aquatic animals.

Background: Myogenic factor 6 (Myf6) plays an important role in muscle growth and differentiation. In aquatic animals and livestock, Myf6 contributes to improving meat quality and strengthening the accumulation of muscle flavor substances. However, studies on Myf6 gene polymorphisms in crustaceans have not been reported. Results: In the current study, we characterized the Myf6 gene for Portunus trituberculatus to better understand its biological function. The full-length cDNA of Myf6 was 4,101 bp, with a 915 bp open reading frame encoding 304 amino acids. In addition, Myf6 included a conservative bHLH domain. Homology analysis showed that Myf6 shared the highest identity with Penaeus vannamei. Expression pattern analysis of Myf6 in fast- and slow-growing groups revealed that the expression level of the latter was significantly higher than that of the former (P < 0.05). qPCR studies revealed that Myf6 was expressed in various tissues with the highest level in muscle. Nineteen single nucleotide polymorphisms (SNPs) of Myf6 were identified and five of them were significantly associated with growth-related traits of P. trituberculatus (P < 0.05), including full carapace width, carapace length, body height, and body weight. The AG and GG genotypes of g.1,187,834 A > G exhibited superior growth-related traits than the AA genotype. In the combined genotypes of g.1,187,324 C > T and g.1,187,834 A > G, the average body weight of diplotype D5 (CT-GG) was higher than that of diplotype D1 (CC-AA), D2 (CC-AG), and D3 (CC-GG) in a cultivated population. A haploblock was generated by three significant SNPs (g.1187834 A > G, g.1188616 A > G, and g.1189024 C > A), containing four haplotypes (AAA, AAC, AGC, and GGC), among which GGC haplotype exhibited superior growth traits (full carapace width and body weight) than the AAA haplotype. Conclusions: To our knowledge, this is the first report on Myf6 in crustaceans. The results of this study would contribute to elucidating multiple functions of the Myf6 gene in crustaceans and exploring the potential as a candidate gene in selective breeding programs of P. trituberculatus. [ABSTRACT FROM AUTHOR]

The antioxidant and anti‐inflammatory functions of genistein (GEN) and the regulatory mechanisms have been intensively investigated in mammals; however, there was a paucity of studies in aquatic animals. The purpose of this study was to evaluate the effects of GEN on lipopolysaccharide (LPS)‐induced hepatic oxidative stress and inflammatory responses in turbot (Scophthalmus maximus L.) juveniles. Turbots (20 g body weight) were intraperitoneally injected with PBS (the Control group), LPS (50 μg/g), and LPS (50 μg/g) + GEN (0.05, 0.5 and 5 μg/g), respectively. Results showed that the content of the total bilirubin, the activities of the alanine aminotransferase, aspartate aminotransferase, γ‐glutamyl transpeptidase, and alkaline phosphatase were significantly decreased with increasing levels of GEN injection (p < 0.05). Results exhibited that hepatic proinflammatory factors, oxidative stress‐related factors, and apoptotic factors mRNA expression were significantly upregulated after intraperitoneal injection of LPS in turbot, compared with the Control group (p < 0.05). Meanwhile, the mRNA expressions of these apoptosis‐ and inflammation‐related factors showed significant linear or quadratic terms of downregulation with increasing levels of GEN injection (p < 0.05) and almost reached the lowest values at 0.5 μg/g or 5 μg/g of GEN injection levels. The symptoms of LPS‐induced disorganization of hepatocyte arrangement, vacuolization of hepatocytes, and inner mitochondrial cristae damage in turbot were significantly improved after GEN injection. Furthermore, the main signaling pathways associated with inflammation included Herpes simplex virus 1 infection, RIG‐I‐like receptor, NOD‐like receptor, C‐type lectin receptor, and p53 signaling pathways. Moreover, results of weighted correlation network analysis indicated that vascular endothelial growth factor A–A (vegfaa) and signal transducer and activator of transcription 3 (stat3) were likely to be hub genes. Meanwhile, mRNA expressions of vegfaa, vegfab, stat1, stat2, stat3, stat4, stat5a, and stat5b exhibited significantly linear or quadratic downregulation with increasing levels of GEN injection (p < 0.05). The above results confirmed that intraperitoneal injection of GEN significantly alleviated LPS‐induced hepatic oxidative stress and inflammatory injury in turbot, and vegfaa and stat3 possibly play a key role in this process. [ABSTRACT FROM AUTHOR]

Phylosymbiosis is defined as the relationship in which the microbiome recapitulates the phylogeny of the host and has been demonstrated in a variety of terrestrial organisms, although it has been understudied in fish, the most phylogenetically diverse vertebrate. Given that the species-specificity of fish microbiomes was detected in multiple body parts and differed by body parts, we assumed that the phylogenetic reflection of the microbiome would differ across body parts. Thus, we analyze the difference of phylosymbiotic relationships in the microbial communities found in three body parts (skin, gills, and intestine) of seven wild fish species from four families (Labridae, Sebastidae, Sparidae, and Rajidae) via 16S rRNA gene amplicon sequencing. Fishes were purchased at Docheon port market in Tongyeong City, Korea and were transported to nearby research institutes for aliveness. Mantel tests using dissimilarity values of microbiomes and hosts' divergence times showed that the differences in microbial communities in all three body parts were related to the hosts' divergence time. This pattern was the most pronounced in the skin. Furthermore, fishes from the same family showed similar bacterial compositions on their skins and gills, with clear differences depending on the family, with the exception of Labridae. These results suggest that the skin microbiome is particularly vulnerable to evolutionary pressures. We hypothesized that the evolution of the fish immune system and the difference in feeding habits induced the stronger phylosymbiotic signal in the skin. Collectively, this dataset will be useful for understanding the fish microbiome and give insights into phylosymbiosis of aquatic animals across body parts. [ABSTRACT FROM AUTHOR]

The article explores the connection between Marlowe's "Faustus," the Horse-Courser, and werewolves, delving into the folkloric origins of the story and its possible interpretations. It discusses how Faustus tricks a horse-courser into buying a horse that turns into straw when it crosses water, drawing parallels to werewolf transformation tales. The text also examines the broader legend of transformation and shape-shifting, linking it to ancient beliefs and anxieties about alchemy and magic. The article suggests that Faustus's failure to transform himself into a Renaissance man reflects the play's themes of conflicting religious and secular views on transformation and knowledge. [Extracted from the article]

Vitamin E (VE) is an essential vitamin liposoluble antioxidant in aquatic animals that is usually lost during feed processing and digestion, whereas nano-chitosan, a polysaccharide, could protect VE. In this study, Nile tilapia (70.85 ± 0.2 g) was fed VE (100 mg/kg dry diet) and a chitosan protected-VE nanoparticle (NPs) with gradual percentages of recommended dose 25%, 50%, 75%, and 100% for 4, 6, and 8 weeks. Growth parameters total weight gain (TG), daily weight gain (DWG), and relative growth rate (RGR) were significantly and positively correlated with VENPs additions. Regardless of the addition level, the feed conversion ratio (FCR) was significantly lower in the VENP groups. Lysozyme, serum antibacterial activity, and oxidative burst activity indicated the superiority of VENPs (VENPs75 and VENPs100) in enhancing the fish's innate immunity compared to bulk VE and the control groups. Fish were experimentally challenged with pathogenic Aeromonas hydrophila; those received dietary showed a low mortality rate (MR%), about 40% compared with 70% in the control with lower re-isolation compared to the control and VE groups. VENPs could provide ascending relative protection level during the period of 4 to 8 weeks; RPL ranged from 33.3 to 42.86% (VENPs100), 16.67–42.86% (VENPs75), 0 to 28.57% (VENPs50), and 0 to 14.29% (VENPs25 and VE), respectively. Finally, this study recommended incorporating VENPs into the Nile tilapia diet at 50, 75, and 100 mg/ kg fish feed. Fish in the VENPs75 and VENPs100 groups were immune boosted, becoming less vulnerable to A. hydrophila infection. [ABSTRACT FROM AUTHOR]

Due to the increased demand for food supplies, the agricultural sector has been enormously expanded and food production has been enhanced using various agrochemicals. Agrochemicals are known to have adverse effects on human health. Additionally, their extensive use has led to bioaccumulation affecting water quality and aquatic fauna. Taking the problem of bioaccumulation, the present study reports the use of CdS/MAX-phase for the photo mineralization of chlorpyrifos in an aqueous solution. CdS/MAX-phase nanocomposites with different loadings of CdS have been prepared via a simple one-pot thermal decomposition approach at 180 °C for 1 hour. The synthesized CdS/MAX-phase nanocomposites were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), diffuse reflectance spectroscopy (DRS), Raman spectroscopy, and field emission scanning electron microscopy (FE-SEM) techniques. A maximum of 93% degradation of chlorpyrifos under visible light exposure using the nanocomposites was observed in 90 minutes with 3 major intermediates, chlorpyrifos-oxon, 3,5,6-trichloro 2-pyridinol, and pyridine. Studies on the effect of the parameters suggested that the best photocatalytic performance was achieved at pH 7.8 and a dosage of 1 mg mL−1. A detailed investigation of the degradation pathways, mineralization studies, and a comprehensive mechanism supported by LC–MS and scavenger studies have been reported in the present study. [ABSTRACT FROM AUTHOR]

The study of aquatic animal movements is a rapidly growing field of research, with tracking methodology ever developing and refining. Acoustic telemetry is arguably the most popular method used to study the movements of fish. Despite this method being able to elucidate many aspects of movement behavior, including residency, home range, and migration, among others, one aspect that remains challenging is the study and definition of connectivity, particularly within marine seascapes. As such, this review assesses published literature on acoustic telemetry studies, which have specifically assessed some aspect of fish connectivity, and discusses these in terms of study distribution and overall trends, the diversity of taxa and life stage assessed, the role that large‐scale acoustic telemetry networks plays in assessing connectivity of marine fishes, how connectivity studies have been used in an applied context, and proposes definitions linked to specific types of connectivity, which will assist future researchers when conceptualizing studies. Further, methods that can be used in conjunction with acoustic telemetry to complement the data are discussed. Given that marine resources and habitats are intricately connected, this review highlights the critical role that acoustic telemetry can play in assessing this link. It is envisaged that our developed framework of connectivity definitions will assist future studies and stakeholders in assessing ecosystem functioning and ultimately contribute to improved conservation and management of marine fish populations and ecosystems. [ABSTRACT FROM AUTHOR]

Microcystin-leucine arginine (MC-LR) poses a serious threat to aquatic animals during cyanobacterial blooms. Recently, biochar (BC), derived from rice straw, has emerged as a potent adsorbent for eliminating hazardous contaminants from water. To assess the joint hepatotoxic effects of environmentally relevant concentrations of MC-LR and BC on fish, male adult zebrafish (Danio rerio) were sub-chronically co-exposed to varying concentrations of MC-LR (0, 1, 5, and 25 μg/L) and BC (0 and 100 μg/L) in a fully factorial experiment. After 30 days exposure, our findings suggested that the existence of BC significantly decreased MC-LR bioavailability in liver. Furthermore, histopathological analysis revealed that BC mitigated MC-LR-induced hepatic lesions, which were characterized by mild damage, such as vacuolization, pyknotic nuclei, and swollen mitochondria. Compared to the groups exposed solely to MC-LR, decreased malondialdehyde (MDA) and increased catalase (CAT) and superoxide dismutase (SOD) were noticed in the mixture groups. Concurrently, significant changes in the mRNA expression levels of Nrf2 pathway genes (cat, sod1, gstr, keap1a, nrf2a, and gclc) further proved that BC reduces the oxidative damage induced by MC-LR. These findings demonstrate that BC decreases MC-LR bioavailability in the liver, thereby alleviating MC-LR-induced hepatotoxicity through the Nrf2 signaling pathway in zebrafish. Our results also imply that BC could serve as a potentially environmentally friendly material for mitigating the detrimental effects of MC-LR on fish. [ABSTRACT FROM AUTHOR]

Aluminum (Al) can cause endocrine disruption in aquatic animals, but assessments of animal social behavior in neotropical teleost fish species with importance for Brazilian aquaculture have still not been addressed so far, which can further complete this ecotoxicological knowledge. In order to evaluate the social behavior and plasma cortisol concentration of fish exposed to Al, we performed a 1 h acute exposure with Astyanax lacustris couples in three different experimental groups: control in neutral pH (CTL/n group), acid pH (pH/ac group), and aluminum in acid pH (Al/ac group; 2.0 mg L−1). An ethogram of social interactions between males and females and swimming activities were performed. Furthermore, the cortisol plasma concentration was measured by enzyme-linked immunosorbent, and the gonadal maturation stage of the animals was evaluated by histology. Adult and mature females in the CTL/n and pH/ac groups were more aggressive and active than mature males, including several attacks on the male. Moreover, males did not present attack behavior in these groups at any time, but did show submission behavior and constant avoidance of female attacks. In the Al/ac, females did not attack males, couple decreased swimming activity, a repetitive movement toward the aquarium surface, and high mucus production were observed, making the water cloudy. Regarding cortisol plasma concentration, males had higher cortisol plasma concentrations than females in the CTL/n and pH/ac groups, which was not observed in the Al/ac group. Therefore, Al in addition to being described in the literature as an endocrine disruptor, it can be considered as behavioral disrupter in A. lacustris in this important freshwater species cultivated in South America. [ABSTRACT FROM AUTHOR]

Genome editing has the potential to improve growth and traits of aquatic animals. Assessment of the feeding habits of the genetically modified farmed fish is necessary, as this is closely related to the assessment of their growth performance, which is one of the most important economic traits. Previously, we developed a novel strategy to produce all-female (AF) common carp (cyp17a1+/−;XX genotype) with genome editing, which exhibited a growth advantage compared to the control carp (including control male and female carp). However, the feeding behavior related to the growth performance of wild-type control and AF common carp remains elusive. The results of feeding and swimming behaviors showed that AF common carp exhibited a faster feeding activities and more active swimming activities, which probably enhanced its growth performance. Brain gene expression analysis revealed AF common carp had a significant upregulation of the orexigenic factors gene expression levels in the fed state, which would further promote the growth of AF carp. Here, AF carp exhibited higher growth performance with higher growth hormone (gh) gene expression. This study provided insight into the growth performance, feeding behaviors and appetite regulation of the genetically modified AF carp and the assessment of feeding behaviors in other genetically modified farmed fish. [ABSTRACT FROM AUTHOR]

Isomalto-oligosaccharides (IMO) are indigestible oligosaccharides that possess low caloric content, acid and alkali resistance, corrosion resistance, easy processing, strong safety, and strong stability among other physicochemical properties. Recent research has found that IMO can act as a signaling molecule to regulate functions such as blood sugar, immunity, and digestion in the body. Its biological functions include regulating the structure of intestinal microflora and promoting growth, regulating the body's immunity, promoting intestinal motility to improve constipation, regulating the body's sugar and lipid metabolism, and adsorbing pathogenic bacteria, among others. At present, IMO is widely used in food, beverages, dairy products, and health supplements, but it is rarely seen in health products and feed for aquatic animals. The article provides reference for the promotion and application and development of IMO in aquatic animals by elaborating on the effects of IMO on the growth, immunity, and antioxidant capabilities of fish, shrimp, and Chinese softshelled turtles. [ABSTRACT FROM AUTHOR]

The ability to impact the immune response of the host has been recognized as essential for the success of a virus during infection. A few groups of viruses can combine these immunomodulatory mechanisms with specific patterns of their own transcriptional and replication regulation to achieve persistence within the host long term. The Herpesvirales order is one of those groups and the resultant state is known as latency. Throughout the years, latency has been studied in many host‐herpesvirus models to attempt to understand the complex and profound effects of this state on the host's systems, and in the hopes of deciphering a way to eliminate the latent state from survivors of the primary infection. Most studies of herpesvirus latency have been conducted on mammalian host species, but this review summarizes the data available regarding herpesviruses in fish species and their latent state. As the field of aquatic animal health research continues to advance, the elucidation of these complex mechanisms will be crucial for disease control, prevention, and treatment. [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]

The aquaculture of decapod crustaceans such as shrimp, crab and crayfish has emerged as a significant contributor to the income of tropical countries. This cultivation is being driven by the growing human population, demand for aquatic animal nutrition, and the diversification of fisheries products. However, the emergence of diseases in decapod aquaculture presents a significant challenge, especially those caused by bacteria and viruses. Decapod crustaceans lack an adaptive immune system and rely on an innate immune system that responds to the recognition of molecular patterns in pathogens. Activation of this response triggers cellular or humoral defense mechanisms to combat pathogens. Hemocytes act as mediators of cellular immune components, while hemolymph contains free-cellular components that contribute to humoral responses. This review discussed an understanding of the characteristics and roles of the hemolymph and hemocytes to decapod health. We also describe the innate immunity systems (i.e., cellular and humoral) in decapod crustaceans and the factors affecting their immunity systems. Common tests used to quickly access decapod health were also highlighted to benefit aquaculturists and seafood processors in accessing their stock health status. All these topics are necessary to know before an outbreak happens, as some communities rely on various decapod species, especially shrimp, for their economic well-being. [ABSTRACT FROM AUTHOR]

The Aphanomyces species pose an important global threat and cause damage to aquaculture and agriculture by infecting aquatic animals and plants. Several subpopulations of the seasonal cyprinodont fish genus Nothobranchius with lesions suggestive of infection with Aphanomyces invadans, were observed in ephemeral wetland habitats of the upper Congo drainage in the south-eastern Democratic Republic of Congo. Molecular analyses on samples collected in 2023 revealed evidence of fish-pathogenic oomycetes Aphanomyces invadans and A. laevis, for the first time in the host of fish genus Nothobranchius spp. All Nothobranchius fishes in the upper Congo drainage are subject to a high level of threat and belong to one of the threatened Red List categories, due to habitat degradation of seasonal wetlands. These fishes complete their seasonal life cycle in ephemeral natural habitats. The latter makes them highly vulnerable, as such wetland habitats are often degraded by the cumulative effect of multiple human stressors which include: the cultivation of wetlands for agriculture, the abstraction of water, the expansion of urban areas and the pollution load. Evidence of infection by oomycete pathogens documented in this study, represents a critical additional threat to the unique seasonal aquatic biodiversity of the region. [ABSTRACT FROM AUTHOR]

Background: In recent years, titanium dioxide (TiO2) nanoparticles (NPs) have been widely used in various industries due to their favorable chemical properties, and their contamination of the environment has attracted much attention, especially to aquatic animals. Methods: Therefore, we assessed the impact of TiO2 NPs (5 mg/L) on the marine bivalve, pearl oyster (Pinctada fucata martensii), especially gill metabolism. Pearl oysters were exposed to seawater containing 5 mg/L TiO2 NPs for 14 days, followed by 7 days of recovery in untreated seawater. Gill tissues and hepatopancreatic tissues were sampled on days 0, 14, and 21 of the experiment named C0, E14, and R7, respectively. Results: Metabolomic analysis identified 102 significantly different metabolites (SDMs) on gills tissue in pearl oysters following exposure to TiO2 NPs (C0 vs. E14). Compared with group C0, group E14 had 76 SDMs (such as acetylcholine, itaconic acid, citric acid, and taurine) with higher concentrations and 26 (including L-arginine and isobutyryl-L-carnitine) with lower concentrations. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis showed that these SDMs enriched 28 pathways, including glycine, serine, and threonine metabolism, neuroactive ligand–receptor interaction, and taurine and hypotaurine metabolism. In addition, 116 SDMs were identified in E14 and R7 pearl oysters. Compared with group E14, group R7 had 74 metabolites (such as acetylcholine, 6-phosphogluconic acid, isocitric acid, and itaconic acid) with higher concentrations and 42 (including uracil, glycerophosphocholine, N-Acetyl-D-glucosamine) with lower concentrations. The SDMs identified between E14 and R7 enriched 25 pathways, including the pentose phosphate pathway, glutathione metabolism, and citrate cycle (TCA cycle). In addition, analysis of the energy metabolism-associated enzymes revealed that exposure to TiO2 NPs reduced Ca2+/Mg2+-ATPase, Na+/K+-ATPase, and Total-ATPase activities. Conclusions: These findings suggested that TiO2 NPs may inhibit the energy metabolism function of gill and hepatopancreas of pearl oysters. Meanwhile, TiO2 NPs may affect the normal functioning of immune and osmoregulatory functions of pearl oysters gill and even may lead to oxidative stress and neurotoxicity. Therefore, this study may provide a reference for analyzing the bioadaptation of marine bivalves to TiO2 NPs and the potential negative effects of TiO2 NPs on bivalves. [ABSTRACT FROM AUTHOR]