Search Results (132)

The large yellow croaker (Larimichthys crocea) is susceptible to microbial contamination during storage due to its high protein and moisture contents. This study was designed to find a new way to reduce bacteria in large yellow croakers by combining slightly acidic electrolyzed water (SAEW) with nano-bubble (NB) technology. Exploring the effects of available chlorine concentration (ACC), processing time, and water temperature on the bacteria reduction effect of the SAEW-NB treatment for large yellow croakers. Also, the effects of the SAEW-NB combined treatment on sensory evaluation, total viable counts (TVCs), total volatile basic nitrogen (TVB-N), texture, taste profile, and volatile flavor compounds of large yellow croakers were analyzed during the storage period at 4 °C. The results show that the SAEW-NB treatment achieved significantly enhanced microbial reduction compared to individual treatments. Under the conditions of a 4 °C water temperature, 40 mg/L ACC, and 15 min treatment, the SAEW-NB treatment inhibited the increases in physical and chemical indexes such as TVC and TVB-N, maintained the fish texture, and delayed the production of off-flavor volatiles such as aldehydes, alcohols, esters, and ketones, compared with the control group (CG) during storage at 4 °C. In conclusion, the SAEW-NB treatment could better retard fish spoilage, extending the shelf life by approximately 2 days. It might be a promising new industrial approach for large yellow croakers’ storage. Full article

Selenium (Se) is an essential trace element critical for animal growth and immune function. This study investigated the dietary selenium requirement of juvenile large yellow croaker (Larimichthys crocea) through an 8-week feeding trial. Five experimental diets were formulated by supplementing a basal diet with selenium polysaccharides (Se-PS) at 0, 20, 30, 40, and 50 mg/kg, resulting in analyzed Se concentrations of 0.35, 0.54, 0.71, 0.93, and 1.11 mg/kg, respectively. The results demonstrated that growth performance and feed efficiency improved with increasing dietary selenium, peaking at 0.93 mg/kg before declining at higher levels. Antioxidant enzyme activities—superoxide dismutase (SOD) and catalase (CAT)—in serum and liver tissues exhibited a dose-dependent increase, reaching maximal levels at 1.11 mg/kg. Conversely, malondialdehyde (MDA), a marker of oxidative stress, progressively decreased in both serum and liver, attaining its lowest concentration at 1.11 mg/kg, though this did not differ significantly from the 0.93 mg/kg group (p = 0.056). Tissue selenium accumulation was highest at these optimal dietary levels. Based on the growth performance, oxidative stress response, and tissue selenium retention, the recommended dietary selenium requirement for juvenile large yellow croaker is 0.93 mg/kg. These findings highlight the importance of optimal Se supplementation in aquafeeds to enhance growth and physiological health in farmed fish. Full article

In this study, we investigated the effects of air packaging, vacuum packaging and modified atmosphere packaging (CO₂/N₂: 80/20) on the purine metabolism and enzyme activities of refrigerated large yellow croakers. The results showed that modified atmosphere packaging significantly inhibited microbial growth, delayed adenosine triphosphate degradation and maintained higher IMP content (1.93 μmol/g on day 21) compared to the air packaging group (2.82 μmol/g on day 12). The total purine content increased with storage time, with hypoxanthine content increasing significantly and occupying most of the total content, which was the key factor for the elevation of purine, followed by adenine content showing a significant decreasing trend. Hypoxanthine accumulation was significantly suppressed in the modified atmosphere packaging group (2.31 μmol/g on day 18), which was much lower than that in the air packaging group (5.64 μmol/g), whereas xanthine and guanine did not show significant differences among the groups. The key enzymes xanthine oxidase and purine nucleoside phosphorylase were much less active in modified atmosphere packaging, effectively delaying the cascade reaction of inosine monophosphate → hypoxanthine → xanthine. The study confirmed that modified atmosphere packaging intervenes in purine metabolism through enzyme activity regulation, providing a theoretical basis for the preservation of low purine aquatic products. Full article

Recent advances in passive acoustic monitoring (PAM) have markedly improved the ability to study marine soundscapes by enabling long-term, non-invasive monitoring of biological sounds across large spatial and temporal scales. Among aquatic organisms, fish are primary contributors to biophony, producing sounds associated with feeding, reproduction, and social behavior. However, the majority of previous research has focused on individual vocalizations, with limited attention to collective acoustic phenomena such as fish choruses. This study quantitatively analyzes choruses produced by the small yellow croaker (Larimichthys polyactis), an ecologically and commercially important species in the Northwest Pacific Ocean. Using power spectral density (PSD) analysis, we examined long-term underwater recordings from a sea cage containing approximately 2000 adult small yellow croakers. The choruses were centered around ~600 Hz and exhibited sound pressure levels 15–20 dB higher at night than during the day. These findings highlight the ecological relevance of fish choruses and support their potential use as indicators of biological activity. This study lays the foundation for incorporating fish choruses into soundscape-based PAM frameworks to enhance biodiversity and habitat monitoring. Full article

Anthropogenic acidification is a long-term challenge to marine ecosystems. Though coastal acidification is intensifying, the large yellow croaker (Larimichthys crocea) exhibits good adaptability to pH fluctuations, the underlying mechanisms of which remain poorly understood. This study investigated the morphology, antioxidant enzyme activity, and gene expression of L. crocea under varying acidification conditions (pH 8.1 (H group), 7.8 (M group), and 7.4 (L group)). Water pH fluctuations were also monitored to explore the physiological responses and potential adaptive molecular mechanisms of L. crocea under various acidified environments. The results indicated that the water pH decreased in the H group, significantly increased in the L group (p < 0.05), and remained stable in the M group during the experiment. The lowest MDA content and the highest antioxidant enzyme activities (CAT, SOD, GSH-Px) were observed in L. crocea at pH 7.8, suggesting pH 7.8 was optimal for L. crocea. Transcriptomic analysis revealed distinct gene expression patterns between the gills and kidneys under acidification stress. Differentially expressed genes (DEGs) in the gills were primarily observed between the M and L groups (62.3%), whereas in the kidneys, the majority of DEGs were observed between the M and H groups (43.2%). These findings suggested that the gills play a critical role in adapting to low pH in L. crocea, while the kidneys were more responsive to high pH. Enrichment analysis identified critical pathways, including vasopressin-regulated water reabsorption, mineral reabsorption, and aldosterone-regulated sodium reabsorption, which are associated with water and ion metabolism. These pathways play a pivotal role in the acid–base homeostasis and metabolism of L. crocea. These results provide insights into the adaptive mechanisms of L. crocea to acidified environments, with implications for aquaculture management and future ocean acidification adaptation. Full article

The large yellow croaker (Larimichthys crocea) is one of China’s most economically important marine fish species, with its cage culture production leading the nation for many years. However, the rapid expansion of aquaculture has brought challenges such as germplasm degradation, reduced disease resistance, inconsistent product quality, and low adoption of improved strains, which have hindered the sustainable development of the industry. The primary objective of this review is to summarize the current practices and challenges in seedling selection for L. crocea. The secondary objectives include discussing the influence of genetic, physiological, and environmental factors on growth performance and proposing future research directions for sustainable breeding programs. This review covers key topics including morphological screening, growth performance evaluation, genetic diversity conservation, disease resistance improvement, and adaptation to environmental stress. It also explores the application of modern technologies such as marker-assisted selection, intelligent monitoring, environmental control, precision feeding, and disease prevention. Moreover, it highlights core issues in current breeding practices, such as over-reliance on single-trait selection and insufficient integration of environmental adaptability and disease resistance. Finally, future trends are discussed, emphasizing the integration of genomic tools with artificial intelligence to promote intelligent, precise, and sustainable breeding approaches. These insights aim to enhance aquaculture productivity while supporting long-term ecological balance and industry sustainability. Full article

The large yellow croaker, or Larimichthys crocea, is highly prized for its golden color and nutritional content. The purpose of this study was to investigate the differences in body composition, mucus biochemical indices and body color in five strains of large yellow croakers (body weight: 347.01 ± 5.86 g). To conduct genetic diversity analyses of the populations, a total of 50 tailfin samples were randomly chosen from the following populations of large yellow croakers: wild (LYC1), Dai-qu population (LYC2), Yongdai 1 (LYC3), Min-yuedong population (LYC4), and Fufa 1 (LYC5). The findings demonstrated that the LYC3 group’s pigment contents, crude protein, crude lipid, and chromatic values were comparable to those of the LYC1 group (p > 0.05). There was no significant difference between the LYC1 and LYC5 groups’ mucus superoxide dismutase (SOD) and catalase (CAT) activities (p > 0.05). The alkaline phosphatases (ALP), acid phosphatases (ACP), and lysozyme (LYS) activities of the mucus in the LYC1 group were not significantly different from the LYC3 group (p > 0.05). The back skin mRNA expressions of tyrosinase (tyr), tyrosinase-related protein 1 (tyrp1), dopachrome tautomerase (dct), microphtalmia-associated transcription factor (mitf), and melanocortin 1 receptor (mc1r) were significantly up-regulated in the LYC2 and LYC4 groups compared to the LYC1, LYC3, and LYC5 groups (p < 0.05). Forkhead box d3 (foxd3), paired box 3 (pax3), purine nucleoside phosphorylase 4a (pnp4a), aristaless-like homeobox 4a (alx4a), cAMP dependent protein kinase (pka), anaplastic lymphoma kinase (alk), leukocyte receptor tyrosine kinase (ltk), and colony stimulating factor (fms) were among the mRNA expressions of the abdominal skin in the LYC1, LYC3, and LYC5 groups significantly higher than those in the LYC2 and LYC4 groups (p < 0.05). In conclusion, the LYC3 group’s crude protein, crude lipid, carotenoid, and lutein contents were most similar to those of the large yellow croaker found in the wild. Furthermore, the molecular mechanism underlying the variations in body color among the various strains of large yellow croakers was supplied for additional research. Full article

The small yellow croaker (Larimichthys polyactis), a migratory estuarine-demersal fish critical to East Asian fisheries, has faced severe population declines because of anthropogenic pressures (e.g., overfishing and anthropogenic habitat modification) and shifting environmental conditions. This study investigates its spatio-temporal habitat dynamics in Hangzhou Bay (2017–2023) using fisheries surveys and species distribution models (SDMs), with insights applicable to Pacific Coast migratory fish conservation. We evaluated the performance of eleven modeling algorithms to identify the most accurate model for predicting small yellow croaker distributions. Our results showed that the random forest algorithm outperformed other models, with a high sensitivity (95.238) and specificity (99.49), demonstrating its ability to capture complex non-linear relationships between environmental factors and species distribution. Depth emerged as the most influential factor, accounting for 30% of the importance in the model, with small yellow croakers preferring deeper waters around 60 m. Salinity was the second most important factor, with higher occurrence probabilities in areas where salinity exceeded 25 PSU. Other environmental factors, such as temperature and dissolved oxygen, had relatively smaller impacts on distribution. Spatially, small yellow croakers were predominantly distributed in offshore regions east of 122.5° E, where deeper waters and higher salinity levels provided suitable habitat conditions. This study underscores the need for targeted management measures, such as habitat restoration, to ensure the sustainable management of small-bodied yellow croaker populations. Full article

High oil content in breaded fried small yellow croaker (BFYC) was reduced using composite batter gels consisting of tapioca starch, wheat flour, and different concentrations of cassia gum (CG; 0%, 0.2%, 0.4%, 0.6%, 0.8%, 1%). The effects of CG on the oil absorption capacity of BFYC and potential mechanisms were investigated. Dynamic rheological analysis revealed that CG addition could enhance the viscoelasticity of the batter by increasing its storage modulus and loss modulus. Furthermore, FTIR and X-ray diffraction results demonstrated that CG interacts with starch through noncovalent interactions, increasing the relative crystallinity from 9.29% to 16.49%, which promoted the formation of a gel layer. This structural improvement effectively inhibited oil absorption. Differential scanning calorimetry analysis showed that within the 0–0.8% CG range, the batter’s denaturation temperature increased from 78.23 °C to 82.08 °C with higher CG concentrations, indicating prolonged gelatinization and enhanced thermal stability that further reduced oil penetration. Low-field nuclear magnetic resonance analysis revealed that CG increased the proportion of tightly bound and weakly bound water in the batter, thereby improving water retention capacity and reducing moisture loss during frying. Microscopic structural observations and Sudan Red-staining tests confirmed that at 0.8% CG concentration, the crust exhibited the lowest porosity with approximately 40% reduction in surface fat content compared to the control group. In conclusion, CG addition significantly improves batter properties and reduces oil content in fried products, providing theoretical support for the development of low-fat fried foods. Full article

Aeromonas salmonicida is a common spoilage bacterium found in refrigerated fish. In this study, a virulent bacteriophage was isolated from wastewater using A. salmonicida AS08 as the host, and it was designated as TSW001. Based on morphological characterization and whole-genome analysis, bacteriophage TSW001 was classified within the genus Tedavirus. Biological characterization revealed that TSW001 maintained a stable titer within a temperature range of 4~60 °C, a pH range of 4~9, and a salinity range of 50~1000 mM. The optimal multiplicity of infection (MOI) for TSW001 was 0.1, with a short latency period of approximately 10 min and a burst size of approximately 68 PFU/cell. When applied during the cold storage of large yellow croaker, the A. salmonicida count in the fish juice decreased by approximately 2.1~2.3 log₁₀ CFU/mL over the first two days, while the count in the fish fillets decreased by approximately 1.1~1.8 log₁₀ CFU/g. Furthermore, TSW001 demonstrated the ability to inhibit the formation of A. salmonicida biofilms. These results suggest that phage TSW001 is a promising biological antimicrobial agent for controlling A. salmonicida during the cold storage of seafood. Full article

Various volatile compounds are responsible for the odor changes in fish during storage. In this study, a coupled headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry (GC-MS) analytical approach was applied to characterize the volatile compounds in large yellow croaker (Pseudosciaena crocea) during storage under three treatments: cold storage (CS), slurry ice (SI), and crushed ice (CI). A total of 24 volatile substances were identified, including aldehydes, ketones, and alcohols. Multivariate statistical analyses (PCA, PLS-DA, VIP, and cluster heatmap) revealed significant differences in volatile compounds between the treatment groups during storage, and 10 key volatiles along with 5 potential biomarker compounds were identified. The underlying mechanisms of volatile changes were further investigated by analyzing three key pathways: thermal reactions, lipid oxidation, and amino acid degradation. Notably, SI treatment better avoid volatile compound variation in large yellow croaker. Full article

E2F transcription factors regulate cell cycle progression by influencing the expression of proteins required for the G₁-S phase transition and DNA synthesis with its heterodimeric partners (DP1 or DP2). The dimerization domain is the E2Fs and DP1 protein interaction interface and is believed to function in protein dimerization. In this study, eight E2F transcription factors (PcE2F1–8) of large yellow croaker Pseudosciaena crocea and one dimerization partner (PcDP1) are identified in the genome of large yellow croakers. The prediction of E2Fs conserved domains revealed that PcE2F1–6 has one DNA-binding domain (DBD) and one dimerization-binding domain (DD), while PcE2F7–8 only possess two duplicate DBDs but not DD, indicating that E2F7–8 cannot form the E2F/DP1 heterodimer. To explore whether PcDP1 is a partner of PcE2F1–6, the ORF of PcE2F1–6 was cloned. Subsequently, its sequence characteristics, the expression pattern in healthy fish, and subcellular co-localization were analyzed, and an interaction between PcDP1 and PcE2F1–6 were detected directly by yeast two-hybrid and BiFC. The PcE2F1, PcE2F2, PcE2F3, PcE2F4, PcE2F5, and PcE2F6 genes encode a protein of 454, 448, 444, 392, 362, and 396 amino acids, respectively, with accession numbers QFZ93593.1, QFZ93594.1, QFZ93595.1, QFZ93596.1, QFZ93597.1, and QFZ93598.1, respectively. Sequence characteristics analysis found that PcE2F1–5 but not PcE2F6 proteins share the pocket protein-binding domain sequestering in dimerization domains and transactivation domains. The PcE2F1,2,4 proteins possess one nuclear localization signal (NLS), and PcE2F3 protein possess two NLSs, but there is no NLS in PcE2F5 and 6 protein. Moreover, PcE2F4 also contains one NES. However, PcE2F1–6 proteins were all located in nucleus by using Euk-mPloc 2.0 programs and were confirmed by performing the Cherry and EGFP reporter assay. Regarding co-expression of DP1, only E2F4 can transfer DP1’s subcellular location from cytoplasm to the nucleus. RT-qPCR analysis indicated that PcE2F1–6 are constitutively and tissue specifically expressed in all of the tissues tested of a healthy large yellow croaker. The PcE2F1–6, except for PcE2F3, mRNA levels were all detected higher in the liver. PcE2F1–4 were also highly specifically expressed in the kidney, PcE2F4,6 in the brain, and PcE2F5 in the spleen of a healthy large yellow croaker, respectively. Using a yeast two-hybrid system, PcE2F4 interacting with PcDP1 was identified. The interaction between PcE2F4 and PcDP1 was further confirmed by a bimolecular fluorescence complementation (BiFC) assay. Collectively, these results indicate that an interaction between PcE2F4 and PcDP1 was detected, which may form heterodimer E2F4/DP1 to regulate cell cycles and immune-related pathways in large yellow croakers. Full article

To investigate the effects of water-soluble taste substances (WSTSs) on the physical properties and thermal coagulation properties of reconstituted surimi gels, this study used large yellow croaker muscle (FM) and the WSTS from by-product minced meat (MM) (skin, tail, and head meat (HM)). It was observed that these exogenous additions could effectively improve the surimi gel’s whiteness, gel strength and umami amino acid content. When these were added, the relaxation times of bound water in FM, MM and HM groups were shorter in the 10% exogenous addition treatment, and the surimi particle size (D10, D50, D90, d4, 3, d2, 3) was smaller. This implies a correlation between the WSTS and the moisture preservation capacity of recombinant surimi gels, whereby WSTS facilitates the cross-linking of protein molecules, leading to the formation of a densely interconnected network architecture. This research can provide theoretical guidance for the processing of surimi gel combined fish flavor substances and freshwater surimi, thereby improving the flavor characteristics of freshwater surimi gel. Full article

In this study, large yellow croaker (Pseudosciaena crocea) protein isolates/gellan gum (PG) binary hydrogels with dense microstructure were used for embedding and delivery curcumin (Cur). The colitis-relieving effects of PG-Cur were further investigated using the dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mouse model. Following PG-Cur treatment, weight loss, diarrhea, and shortening of the colon were significantly alleviated. Compared with the free Cur group, weight loss and colon length in the PG-Cur group increased about 1.05- and 1.12-fold. IL-1β, IL-6, TNF-α, and IL-10 levels in PG-Cur group were not significantly different from those of the normal mice, and the MPO and iNOS activities of the PG-Cur group were 29% and 20% lower than those in the Cur group, respectively. Moreover, fecal microbiota analysis of mice revealed that PG-Cur effectively restored gut dysbiosis in DSS-induced colitis, enriching beneficial bacteria while reducing harmful ones. Overall, the PG hydrogels have the potential to serve as carriers for oral curcumin formulations aimed at alleviating UC. Full article

This study aims to clarify the influence of water flow on the behavior of the large yellow croaker (Larimichthys crocea). Although L. crocea is a key species in marine cage aquaculture, and the industry is increasingly adopting large-scale sea cages, the behavioral adaptations of this species under such conditions remain insufficiently characterized. To solve this problem, the study implemented an ultrasonic biotelemetry system to monitor the in situ swimming behavior of L. crocea across varying current velocities and tidal phases. The results indicated that the tagged fish predominantly occupied water depths of 1 to 2.6 m, with no observable circular swimming behavior along the cage periphery. Additionally, the spatial distribution of L. crocea within the large-scale cage seemed to correlate with the direction of the current. Furthermore, both the frequency of appearance and swimming speed of L. crocea were higher in the center of the cage compared to the peripheral regions during flood and ebb tides, whereas the opposite trend was observed during slack water. This study provides novel insights into the behavioral ecology of L. crocea in large-scale aquaculture systems. Full article