Search Results (39)

Pseudobagras ussuriensis is a valuable freshwater fish species with enormous breeding potential. To clarify the relationship between the main visceral indices and body weight in this species, 139 cultured individuals were randomly selected to measure body weight and six major organs (namely the intestine, liver, swim bladder, kidney, spleen, and gonadal), and then the causal network of internal organs and body weight of one-year-old P. ussuriensis was analyzed by path analysis, and sex-specific regression models were developed. The results showed that the correlations between body weight and the masses of the intestine, liver, swim bladder, kidney, and gonad were significant, while the spleen mass showed a significant positive correlation with body weight. Path analysis revealed that the direct path coefficients of the intestine, liver, swim bladder, kidney, and gonad on body weight were significant, and that of the spleen was significant. Through regression analysis, multiple linear regression equations were established. Importantly, the swim bladder had the greatest direct effect on body weight in males, whereas the intestine exhibited the strongest direct effect in females. These findings provide valuable insights for the selection and breeding of P. ussuriensis based on visceral indices. Full article

The potential hazards of triazole fungicides to non-target organisms necessitate environmental risk assessment. This study, therefore, focused on characterizing the differential toxicity of the enantiomers of Ipfentrifluconazole (IFZ), a new triazole fungicide, in zebrafish larvae using a multi-endpoint approach. Acute toxicity tests determined the LC₅₀ values of 1.709 mg/L for rac-IFZ, 1.531 mg/L for (+)-IFZ, and 1.809 mg/L for (−)-IFZ, indicating a higher toxicity of the (+)-enantiomer. To avoid overt mortality while revealing organ-level effects, we chose a concentration of approximately 20% of the LC50 of (+)-IFZ, which is 340 μg/L, as the exposure concentration. Exposure to IFZ induced developmental defects, including swim bladder malformation, cardiac blood pooling, and metabolic disturbances during the early developmental stage of zebrafish. Additionally, cardiac and hepatic development and function were disrupted in zebrafish larvae following IFZ exposure. Biochemical and transcriptomic analyses revealed distinct toxic mechanisms: (+)-IFZ primarily disrupted lipid metabolism through alterations in PPAR signaling pathway and fatty acid degradation, while (−)-IFZ significantly impaired cardiac function by affecting adrenergic signaling in cardiomyocytes and cardiac muscle contraction. Rac-IFZ mainly influenced drug metabolism, particularly cytochrome P450-related pathways. These findings demonstrated the toxic effects of IFZ, emphasizing the need for evaluating environmental and health risks of chiral pesticides. The study provides valuable insights into the molecular mechanisms underlying IFZ toxicity. Full article

Oxidative stress is a factor implicated in chronic diseases and aging, motivating the search for natural antioxidants. Over the past ten years, food-derived peptides have been recognized as potent antioxidants. Carp, a globally farmed fish, is a protein-rich raw material for producing antioxidant peptides and hydrolysates. This review summarizes the current knowledge on these antioxidant peptides and hydrolysates, including their production, bioactivity, and applications. We discuss how enzymatic hydrolysis of carp by-products (e.g., skin, scales, and swim bladders) represents a strategy for waste valorization. Cellular and in vivo findings demonstrate the effectiveness of carp peptides and hydrolysates in tackling oxidative stress by reducing reactive oxygen species and enhancing cellular antioxidant enzymes. In addition to their antioxidant properties, these peptides and hydrolysates also possess anti-inflammatory, anti-melanogenic, and wound-healing properties. Potential applications of carp peptides and hydrolysates include their use as natural food preservatives and as active ingredients for skincare, nutraceuticals, and sports nutrition. Future research should focus on validating the in vivo bioavailability and assessing the long-term safety of carp peptides and hydrolysates to support their potential application in health. Carp-derived peptides are a valuable resource for developing functional foods and health products, which can contribute to a more sustainable food industry. Full article

The threadsail filefish, Stephanolepis cirrhifer, is an economically important marine species. However, wild catches have sharply decreased over the past 20 years, causing S. cirrhifer to be added to the IUCN Red List of Threatened Species. Accordingly, this study seeks to promote technological development for artificial breeding and early life-stage farming by defining the morphological characteristics of ontogenesis. The fertilized eggs, with a diameter of 0.62 ± 0.01 mm, were spherical and sticky and contained multiple oil globules of varying sizes. The embryonic development was observed and divided into eight phases, which were cleavage, blastocyst, gastrula, neurula, organogenesis, muscular contraction, heart pulsation, and hatching. At 3 days post-hatching (dph), the yolk sac was completely absorbed. The eye developed rapidly, and the mouth fissure and anus initially formed. Some larvae were fed on S-rotifers (Brachionus plicatilis). At 6–8 dph, the upper and lower jaws of larvae were gradually covered by leathery skin, and the head-to-body proportion increased. At 14–16 dph, the fin differentiation occurred in the dorsal, anal, and pectoral fins, with widespread distribution of yellow and melanin on the body surface. Swim bladder was clear. The swimming ability of larva was enhanced, resulting in an obvious clustering phenomenon. At 22–25 dph, the end of the notochord continued to tilt upwards, forming a tail fin. The trunk was evenly distributed with protruding circular punctate scales. The snout was covered with leathery epidermis, and the mouth began to round. At 40–45 dph, the juvenile completed metamorphosis, with horizontal dark stripes appearing on the trunk. Pigmented spots appeared on the tail fins. The counts of dorsal and anal fin spines were 34–36 and 32–34 dph, respectively. During the development of larvae and juveniles, the growth parameters, such as total length, standard length, body height, and body weight, were made as growth curves. The slopes of growth curves were calculated. We found two inflexion points occurring in the growth curves, which may be associated with metamorphosis and transitions in feeding habits. These results enrich the biological understanding of filefish species while providing guidance for artificial propagation and fry production in S. cirrhifer. Full article

Emerging contaminants refer to chemical substances that have not been widely regulated but possess the potential to cause adverse effects on both the environment and human health. Antibiotics, as emerging contaminants, pose significant threats to ecosystems and human health due to their widespread use and persistence in the environment. Levofloxacin, a broad-spectrum fluoroquinolone antibiotic, is commonly employed in the treatment of bacterial infections, and has been frequently detected in environmental matrices and freshwater systems. In this study, we assessed the effects of levofloxacin on hatchability, mortality rates, malformations, behavioral changes, and cardiac development in zebrafish embryos by exposing them to varying concentrations of levofloxacin (0, 0.5, 1, 2, 4, and 8 mM). Our results demonstrate that levofloxacin exposure significantly impaired the growth and development of zebrafish larvae, particularly at higher concentrations. Notable effects included reduced body length, abnormal yolk sac and swim bladder development, pericardial edema, prolonged distances between the sinus venosus and arteriolar bulb (SV-BA), and disruptions in heart rate. Quantitative PCR analysis further revealed that levofloxacin exposure significantly upregulated the expression of key cardiac development genes in zebrafish larvae, including nppa, myh6, cacna1ab, myl7, gata4, nkx2.5, tbx2b, and tbx5b. These findings indicate that levofloxacin exposure exerts significant toxic effects on both embryonic and larval growth as well as heart development and gene expression in zebrafish. This study provides critical insights into the potential ecological risks posed by levofloxacin along with other antibiotics while laying a foundation for further investigation into their toxicological mechanisms. Full article

As a highly sensitive vibrational technique, Raman spectroscopy (RS) can provide valuable chemical and molecular data useful to characterise animal cell types, tissues and organs. As a label-free, rapid detection method, RS has been considered a valuable asset in forensics, biology and medicine. The technique has been applied to zebrafish for various purposes, including physiological, biochemical or bioaccumulation analyses. The available data point out its potential for the early diagnosis of detrimental effects elicited by toxicant exposure. Nevertheless, no baseline spectra are available for zebrafish embryos and larvae that could allow for suitable planning of toxicological assessments, comparison with toxicant-elicited spectra or mechanistic understanding of biochemical and physiological responses to the exposures. With this in mind, this work carried out a baseline characterisation of Raman spectra of zebrafish embryos and larvae throughout early development. Raman spectra were recorded from the iris, forebrain, melanocytes, heart, muscle and swim bladder between 24 and 168 h post-fertilisation. A chemometrics approach, based on partial least-squares discriminant analysis (PLS-DA), was used to obtain a Raman characterisation of each tissue or organ. In total, 117 Raman bands were identified, of which 24 were well represented and, thus, retained in the data analysed. Only three bands were found to be common to all organs and tissues. The PLS-DA provided a tentative Raman spectral fingerprint typical of each tissue or organ, reflecting the ongoing developmental dynamics. The bands showed frequencies previously assigned to collagen, cholesterol, various essential amino acids, carbohydrates and nucleic acids. Full article

Iprodione (IDN) is a broad-spectrum fungicide used to treat various fungal infections in plants. Despite its extensive use, assessment of its toxicity in aquatic organisms remains incomplete. This study investigated the deleterious effects of IDN using zebrafish (ZF) as a model organism. ZF embryos, beginning at 2 h post-fertilization (hpf), were exposed to IDN (3.75–40 mg/L), and both mortality and deformities were assessed. The impact of IDN on mortality was concentration-dependent and significant from 14 mg/L. Importantly, IDN induced several deformities at sublethal concentrations, including abnormal somites, reduced retinal pigment accumulation, yolk sac edema, hatching failure, abnormal swim bladders, and spinal curvature. The EC₅₀ values for IDN-induced deformities were 3.44 ± 0.74 to 21.42 ± 6.00 mg/L. The calculated teratogenic index values for all deformities were above 1, indicating that IDN is teratogenic to ZF. IDN-exposed ZF also displayed abnormalities in touch-evoked escape responses. IDN significantly affected heart rate and blood flow, and induced pericardial edema and hyperemia in a concentration-dependent manner, suggesting its influence on cardiac development and the function of ZF. In conclusion, these results suggest that IDN exerts toxic effects on ZF embryos, affecting mortality, development, and behavior. Full article

Fish swim bladder (FSB) is a type of traditional nutraceutical, but the lack of high-quality drying methods limits its premium market development. In order to obtain optimal-quality dried FSBs from Chinese longsnout catfish, the effects of liquid nitrogen pre-freezing (LNF) and drying on the physical properties and flavor of FSB were evaluated. Four methods were used for FSB drying, including natural air-drying (ND), hot-air-drying (HD), LNF combined with freeze-drying (LN-FD), and LNF combined with HD (LN-HD). Color, collagen content, rehydration ratio, textural properties, and flavor characteristics (by GC-IMS, E-nose, and E-tongue) were measured to clarify the differences among four dried FSBs. The results showed that ND cannot effectively remove moisture from FSB as the final product showed a stronger sourness in taste. HD led to a decrease in the collagen content and the collapse of the fiber structure in FSB. Compared to HD, LN-HD showed a higher collagen content (0.56 g/g) and a different flavor fingerprint. FSB treated by LN-FD had better physical qualities in terms of an attractive color, a high collagen content (0.79 g/g), low shrinkage, a higher rehydration ratio (2.85), and a soft texture, while also possessing richer characteristic flavors. The application of LN-FD may help the optimization of the nutrition level, rehydration ability, mouthfeel, and flavor of dried FSB. Full article

The Chinese bahaba (Bahaba taipingensis), belonging to the Sciaenidae family, is one of the largest croakers with a limited geographical distribution. It is a critically endangered fish species according to the IUCN and a protected animal in China. In this study, the morphological characteristics of Chinese bahaba were observed and analyzed across different developmental stages, namely, the embryonic, larval, juvenile, and young fish stages. The results demonstrated that the mature eggs had a terminal yolk and a single oil globule. The eggs remained floating, and the mean diameters of the fertilized egg and oil globules were 1.14 ± 0.09 mm and 0.35 ± 0.07 mm, respectively. The findings revealed that the embryonic development of Chinese bahaba occurs broadly in seven stages, including the blastogenesis, cleavage, blastocyst, gastrula, neuro embryonic, organ differentiation, and membrane emergence stages, which lasted approximately 27 h and 10 min until hatching under 22.5 ± 0.5 °C. After 70 d, the larvae developed into young fish with a mean total length and body length of 97.75 ± 12.61 and 75.27 ± 13.27 mm, respectively. The digestive organs and the swim bladder began to differentiate, and the swim bladder, bladder duct, intestine, stomach, and mouth gradually formed at 2 d after hatching. Juvenile development occurred via six stages and there were certain differences in the morphological characteristics of Chinese bahaba across the different stages of growth and development. This study provides a theoretical reference for studying the growth, development, and artificial breeding of Chinese bahaba. Full article

The purpose of this study was to measure organ blood flow (OBF) in yellow catfish (YC, Pelteobagrus fulvidraco), largemouth bass (LB, Micropterus salmoides), and grass carp (GC, Ctenopharyngodon idella) using the method of fluorescent microspheres. Yellow–green microspheres were injected into the fish via cardiac catheterization using a syringe pump at a rate of 0.8 mL/min. Reference blood samples were collected from the dorsal aorta, and fish tissues were harvested after 5 min and processed for fluorescence spectrophotometric analysis. The results showed that the OBF of the heart increased significantly with the increase in temperature from 20 to 30 °C, while there was no significant difference in the OBF of other organs/tissues in YC. The OBFs of different species of LB and GC were also determined at 25 °C. In GC, the blood flow rates of the heart, spleen, kidney, liver, others, gills, swim bladder, intestines, muscles, and skin were 9.55, 1.00, 10.3, 6.92, 6.70, 6.04, 2.06, 2.81, 1.78, and 3.72 (mL/min/g), respectively. In LB, the blood flow rates of the same organs were 8.80, 2.33, 1.01, 0.71, 4.11, 2.72, 1.22, 0.54, 9.47, and 0.40 (mL/min/g), respectively. Compared to the OBFs of YC at 25 °C, the OBFs in GC were the highest, followed by LB. These results reflect that OBF in fish has significant species differences. These studies provide fundamental physiological data on OBFs in YC, GC, and LB, which has practical implications for improving the development of disciplines associated with fish physiology. Full article

The attachment of sugar to proteins and lipids is a basic modification needed for organismal survival, and perturbations in glycosylation cause severe developmental and neurological difficulties. Here, we investigated the neurological consequences of N-glycan populations in the spinal cord of Wt AB and mgat1b mutant zebrafish. Mutant fish have reduced N-acetylglucosaminyltransferase-I (GnT-I) activity as mgat1a remains intact. GnT-I converts oligomannose N-glycans to hybrid N-glycans, which is needed for complex N-glycan production. MALDI-TOF MS profiles identified N-glycans in the spinal cord for the first time and revealed reduced amounts of complex N-glycans in mutant fish, supporting a lesion in mgat1b. Further lectin blotting showed that oligomannose N-glycans were more prevalent in the spinal cord, skeletal muscle, heart, swim bladder, skin, and testis in mutant fish relative to WT AB, supporting lowered GnT- I activity in a global manner. Developmental delays were noted in hatching and in the swim bladder. Microscopic images of caudal primary (CaP) motor neurons of the spinal cord transiently expressing EGFP in mutant fish were abnormal with significant reductions in collateral branches. Further motor coordination skills were impaired in mutant fish. We conclude that identifying the neurological consequences of aberrant N-glycan processing will enhance our understanding of the role of complex N-glycans in development and nervous system health. Full article

Background: Urothelial bladder carcinoma (UBC) is the most frequent histologic form of bladder cancer, constituting 90% of the cases. It is important to know the risk factors of UBC to avoid them and to decrease its recurrence after treatment. The aim of this review was to provide an overview of the risk factors associated with UBC incidence. Methods: A comprehensive literature search from 2012 to 2024 was carried out in databases such as PubMed, Google Scholar, and Medline with potential keywords such as “bladder cancer”, “urothelial bladder cancer”, “incidence of urothelial bladder cancer worldwide”, “mortality rate of bladder cancer”, “incidence according to gender”, “treatment for bladder cancer”, and “risk factors of bladder cancer”. Smoking tobacco was comprehended to be the major risk factor for UBC. Smoke from tobacco products contains polycyclic aromatic hydrocarbons (PAHs) and aromatic amines such as 4-aminobiphenyl, which are known to cause UBC. Smoking-related bladder cancer mortality ranks just second to smoking-related lung cancer mortality. For non-smokers, pollution became a major risk factor associated with UBC. Polycyclic aromatic hydrocarbons (PAHs) are linked to many cancers, especially to UBC. Indoor and outdoor pollution generates VOCs (volatile organic compounds) and PAHs. Small-particle matter < 2.5 is linked to UBC and lung cancers. Drinking chlorinated water is linked to UBC. Also, swimming in chlorinated pools that produce trihalomethanes increases the risk of many cancers, and especially of bladder cancer. Occupational exposure to carcinogens, specifically aromatic amines, is a significant UBC risk factor. It has been estimated that approximately 20% of all UBCs may be linked to this type of exposure, primarily in industrial settings that treat dye, paint, petroleum chemicals, and metal. The other risk factors included genetics, diet, and medical conditions. Alcohol, consumption of processed meat and whole milk, and higher intakes of selenium and vitamins A and E also contribute to the development of UBC. Further, chemotherapeutic agents, oral hypoglycemic drugs, and radiation therapy are positively associated with UBC. Conclusions: The significance of the initial prevention of UBC must be emphasized, and especially programs for quitting cigarettes should be encouraged and supported. However, smoking is not the only risk factor for UBC. For non-smokers, other risk factors should be investigated. Air and water pollution are linked to UBC. Indoor and outdoor pollution should be more controlled. Patients and people should be informed of the risk of drinking chlorinated water and swimming in chlorinated pools. Full article

Salt is frequently introduced in ecosystems, where it acts as a pollutant. This study examined how changes in salinity affect the survival and development of zebrafish from the two-cell to the blastocyst stage and from the blastocyst to the larval stage. Control zebrafish embryos were cultured in E3 medium containing 5 mM Sodium Chloride (NaCl), 0.17 mM Potassium Chloride (KCL), 0.33 mM Calcium Chloride (CaCl₂), and 0.33 mM Magnesium Sulfade (MgSO₄). Experiments were conducted using increasing concentrations of each individual salt at 5×, 10×, 50×, and 100× the concentration found in E3 medium. KCL, CaCl₂, and MgSO₄ did not result in lethal abnormalities and did not affect early embryo growth at any of the concentrations tested. Concentrations of 50× and 100× NaCl caused embryonic death in both stages of development. Concentrations of 5× and 10× NaCl resulted in uninflated swim bladders in 12% and 65% of larvae, compared to 4.2% of controls, and caused 1654 and 2628 genes to be differentially expressed in blastocysts, respectively. The ATM signaling pathway was affected, and the Sonic Hedgehog pathway genes Shh and Ptc1 implicated in swim bladder development were downregulated. Our findings suggest that increased NaCl concentrations may alter gene expression and cause developmental abnormalities in animals found in affected ecosystems. Full article

Triclopyr, an auxin-like herbicide that is widely employed for managing weeds in food crops and pastures, has been identified in various environmental settings, particularly aquatic ecosystems. Limited understanding of the environmental fate of this herbicide, its potential repercussions for both the environment and human health, and its insufficient monitoring in diverse environmental compartments has caused it to be recognized as an emerging contaminant of concern. In this study, we have investigated how triclopyr affects zebrafish, considering a new alternative methodology. We focused on the endpoints of developmental toxicity, neurotoxicity, and behavior of zebrafish embryos and larvae. We determined that triclopyr has a 96 h median lethal concentration of 87.46 mg/L (341.01 µM). When we exposed zebrafish embryos to sublethal triclopyr concentrations (0.5, 1, 5, 10, and 50 μM) for up to 144 h, we found that 50 µM triclopyr delayed zebrafish egg hatchability. Yolk sac malabsorption was significant at 0.5, 1, 5, and 10 µM triclopyr. In zebrafish larvae, uninflated swim bladder was significant only at 50 µM triclopyr. Furthermore, zebrafish larvae had altered swimming activity after exposure to 10 µM triclopyr for 144 h. In summary, these comprehensive results indicate that even low triclopyr concentrations can elicit adverse effects during early zebrafish development. Full article

Essential oils have gained significant popularity in various industries due to their biological properties, but their potential toxic effects on living organisms have been poorly investigated. This study aimed to evaluate the effects of lemongrass, thyme, and oregano essential oils on zebrafish embryos and larvae as animal models. Embryos were exposed to different concentrations of essential oils, and various endpoints were assessed, including epiboly, mortality (LC50), morphometry, and behavioral changes. All three essential oils reduced epiboly, affecting embryonic development. LC50 values were calculated for lemongrass (3.7 µg/mL), thyme (14.4 µg/mL), and oregano (5.3 µg/mL) oils. Larvae exposed to these oils displayed morphological defects, including growth reduction, spinal deformation, pericardial edema, eye size reduction, and reduced swim-bladder inflation. Morphometric analysis confirmed reduced larval length at higher oil concentrations. Essential-oil exposure altered zebrafish larval swimming behavior, with lemongrass oil reducing dark-cycle activity and oregano oil increasing light-cycle activity, suggesting neurodevelopmental toxicity. These findings illustrate the adverse effects of these oils on zebrafish embryos and larvae and reveal essential-oil toxicity, indicating careful use should be considered, particularly during pregnancy. Full article