Pacific Saury Research Articles

Spatial Distribution and Growth Variability of Juveniles of Two Myctophid Species (Myctophum asperum and Symbolophorus evermanni) in Relation to Environmental Factors in the Kuroshio Current System in Winter

ABSTRACTThe distribution and growth rate of juveniles of two myctophid species (Myctophum asperum and Symbolophorus evermanni) were examined in relation to environmental factors, based on samples collected in the Kuroshio Current system during winter from 2020 to 2022. The growth rate of juveniles was compared among three oceanic regions: the inshore side of the Kuroshio axis, the Kuroshio axis, and the offshore side of the Kuroshio axis in relation to sea surface temperature (SST), sea surface salinity (SSS), chlorophyll‐a concentration (CHL), and biomass of zooplankton (ZPB). M. asperum juveniles were distributed mainly in the inshore region and the Kuroshio axis of higher CHL and ZPB, whereas S. evermanni juveniles were distributed mainly in the Kuroshio axis and in the offshore regions of higher SST and SSS. No significant difference in growth rate was found among the three regions for M. asperum juveniles, whereas the growth rate of S. evermanni juveniles in the Kuroshio axis was higher than in the offshore regions. No environmental factors were selected for growth rate of M. asperum in the GLMM, whereas SST was selected for S. evermanni. M. asperum juveniles can be considered to have a higher tolerance for variability in environmental factors, whereas water temperature could be the driver for the distribution and growth rate of S. evermanni. Lastly, we discuss possible interspecific interactions among noncommercial fish (myctophids) and commercial fish (Pacific saury Cololabis saira).

A preliminary application and its error estimates of a simple stereo-camera measure system for the far-sea fishery of Pacific saury

Pacific saury is one of the most economically important species in the northwestern Pacific Ocean. The management of this resource relies on precise input of biological data such as body length and is often hindered by a lack of such data on captured fish. This study explores the potential of electronic monitoring (EM) using off-the-shelf stereo cameras to overcome the challenges of collecting and measuring saury body length from the Pacific saury fishery. Using a calibrated WEEVIEW SID WV3000 3D camera, a total of 252 paired images with different shooting angles and distances were obtained for further measurement using Sebastes Stereo Image Analysis Software (SSIAS). The treatments for the measurement distance (MD) were 30 cm, 60 cm, and 100 cm, for the depression angle (DA) were 30°, 60°, and 90°, and for the position angle (PA) were 0°, 45°, and 315° (− 45°). An assistant calibration (AC) in the form of a 16 cm black ruler was also added used. The SSIAS measurement results indicated that the best measurement was obtained with 0° position angle, 90° depression angle, and 30 cm distance from the target fish. The use of AC in the SSIAS + AC measurement was proven to reduce the measurement error from 2.45 to 8.64% to − 1.86 to 0.01%. This study set the baseline for the application of EM on collecting saury body length and the use of AC has been proven to increase the measurement accuracy.

Risk assessment of As, Cd, Cr, and Pb via the consumption of seafood in Haikou

In order to mitigate the risk of excessive heavy metal intake, a study was conducted to assess the levels of arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb) contamination in 23 edible seafood species obtained from markets in Haikou. The findings were analyzed to evaluate the potential health hazards posed to the local population through consumption. The metals were detected via inductively coupled plasma mass spectrometry (ICP-MS) for quantification. The non-carcinogenic and carcinogenic health risks in humans were assessed via target hazard quotient (THQ), combined target hazard quotient (CTHQ), and target cancer risk (TR). The results indicated that the rank order based on the median metal concentration was As > Cd > Cr > Pb. THQ and CTHQ showed that nine seafood species posed a non-carcinogenic risk regarding from As and Cd consumption separately, or the four targeted metals ingestion together. TR assessment indicated that the InAs in all the species presented a carcinogenic risk to coastal residents. The Cd content in bivalves, algae, and several crustacean (Mantis Shrimp, Orchid Crab, Red spot Swimming Crab) and fish species (Japanese Scad, Pacific Saury), and Cr levels in most bivalve species (Razor Clams, White Clams, Fan Shells, Oysters, Blood Clams) presented a carcinogenic risk. The As, Cd, Pb, and Cr levels of seafood in Haikou were assessed species presented a potential health risk. Necessitating stricter risk should be management and detection capability and monitoring will be improved.

UPLC-ESI-MS/MS strategy to analyze fatty acids composition and lipid profiles of Pacific saury (Cololabis saira)

The Pacific saury (Cololabis saira) is a highly nutritious deep-sea fish, rich in omega-3 polyunsaturated fatty acids (n-3 PUFAs). This study comprehensively investigated fatty acids composition and lipid profiles of different parts of Pacific saury based on an untargeted lipidomic strategy. Results suggested that the crude fat content of meat, head and viscera were 5.81%, 10.90%, and 19.46%, respectively. The contents of PUFAs were 41.08%, 34.96% and 33.14%, respectively. Among them, the n-3 PUFAs in the head (34.58%) were significantly higher than meat (29.40%) and viscera (27.95%). Moreover, 5752 lipid molecules were identified, where glycerophospholipids (GP) were the most numerous lipid type (45.58%), with phosphatidylcholine (PC) being main differential subclass. PC (20:3_22:6) was the most abundant molecule in the head (14.59%) and meat (19.60%). Head_vs_viscera group had higher characteristic PC abundance. This study will provide a theoretical basis for the physiological activity and lipid high-value utilization of Pacific saury.

Mercury bioaccumulation and trophic transfer in Pacific Saury from the North Pacific Ocean

This study investigates mercury (Hg) dynamics in Pacific Saury (Cololabis saira) across the North Pacific Ocean, specifically off East Japan in 2018. Saury traits vary with total mercury (THg) concentrations in muscle tissues ranging from 0.017 to 0.082 μg g−1 w. w., averaging of 0.042 (n = 46). A positive correlation between THg and saury length (Knob length, 270–319 mm) indicates increased Hg concentration with size. Stable isotopic tracers suggest Pacific Euphausiids (Krill) are significant contributors to the saury diet (>70% of total). Significant correlations between logarithm THg concentration (Log THg) and δ15N (‰) (R2 = 0.70) demonstrate Hg trophic biomagnification, with regional variations. Comparative analysis between the eastern (ENPO) and western North Pacific Ocean (WNPO) indicates differences, with WNPO saury exhibiting lower δ15N values and higher THg levels than ENPO saury. This suggests that the WNPO, located near East Asia, the world's largest Hg emitter, experiences elevated Hg levels in seawater due to anthropogenic release. Overall, this study advances understanding of Pacific Saury's ecological interactions and Hg bioaccumulations, emphasizing the importance of species-specific behaviors and regional influences in ecological studies.

Identification and in silico screening of novel angiotensin-converting enzyme inhibitory peptides from pacific saury: Interaction mechanism, network pharmacology, stability, Caco-2 monolayer transport

Angiotensin-converting enzyme (ACE) inhibitory peptides (ACEIPs) have garnered enormous attention in maintaining blood pressure balance of humans. In this study, the amino acid sequence of Pacific saury ultrafiltration fraction was identified by Nano-LC-Q-Orbitrap-MS/MS. Through in silico screening, eight novel ACEIPs were elected to synthesize, among of which the VFPLK (IC50 value of 60.7 μΜ) exhibited the strongest ACE inhibitory ability. The interaction mechanism of VFPLK and ACE was explored. To be specific, the VFPLK was a mix pattern based on the Lineweaver–Burk plot, formed six hydrogen bonds with ACE according to the molecular docking and exhibited good affinity with ACE by molecular dynamic simulation. The core targets of VFPLK against hypertension were predicted to be ALB, AKT1, MMP9, IGF1 and NOS3 by network pharmacology. Besides, VFPLK showed good stability in temperature, pH and gastrointestinal digestion. Moreover, the apparent permeability coefficient of VFPLK was determined to be 1.09 × 10−6 cm/s, and paracellular transport via tight junctions was the primary pathway across the Caco-2 cell monolayer. Finally, the concentration 0.2–1.5 mg/mL of VFPLK disclosed no toxicity for EA.hy26. Collectively, VFPLK could be a beneficial constituent in nutraceuticals and functional foods for combating antihypertensive and related diseases.

The role of ultraviolet radiation in the flavor formation during drying processing of Pacific saury (Cololabis saira).

Traditional sun-drying aquatic products are popular and recognized by customers, owing to their unique flavor and long-term preservation. However, the product quality and production efficiency cannot be guaranteed. Cololabis saira is rich in unsaturated fatty acids, which are susceptible to hyperoxidation during the drying process. This study aimed to make clear the role of ultraviolet (UV) radiation in flavor formation during drying processes of Cololabis saira to develop a modern drying technology. Lipid oxidation analysis revealed that moderate hydrolytic oxidation occurred in the UV-assisted cold-air drying group due to the combined influence of UV and cold-air circulation, resulting in the thiobarbituric acid reactive substances value being higher than that of cold-air drying group but lower than the natural drying group. Hexanal, heptanal, cis-4-heptenal, octanal, nonanal, (trans,trans)-2,4-heptadienal, (trans,trans)-2,6-nonanedial, 1-octen-3-ol, heptanol, 2,3-pentanedione, 3,5-octadien-2-one and trimethylamine were identified as the characteristic flavor odor-active compounds present in all Cololabis saira samples. Yet, during the natural drying process, sunlight promoted the lipid oxidation, resulting in the highest degree of lipid oxidation among three drying methods. Light and heat promoted lipid oxidation in Cololabis saira prepared through natural drying process, leading to a large accumulation of volatile compounds, such as 3-methylbutyraldehyde, 2,3-pentanedione, 1-propanol, and 3-pentanone. Cold air circulation inhibited lipid oxidation to some extent, resulting in a blander flavor profile. More cis-4-heptenal, cis-2-heptenal, octanal and 2-ethylfuran accumulated during the UV-assisted cold-air drying process, enriching its greasy flavor and burnt flavor. UV-assisted cold-air drying could promote moderate lipid oxidation, which is beneficial for improving product flavor. To sum up, UV radiation played a crucial role in the flavor formation during the drying process of Cololabis saira. © 2024 Society of Chemical Industry.

Preliminary design and hydrodynamic study of power-driven float pole system in Pacific saury fishery

Pacific saury (Cololabis saira), an essential commercial fish species in the North Pacific Ocean, is captured primarily using the stick-held dip net (SHDN) method. During the netting process, the separation of the gear from the vessel is dependent on the wind and currents, which represents a passive operational approach. In this study, we designed a prototype power-driven device for SHDN gear. The device consists of two thrusters, a remote-control system, and an energy device. It was installed on a 1/10 length segment of a float pole, hereafter referred to as the power-driven float pole (PFP) prototype. Experiments were conducted on both the single-thruster and PFP prototype to investigate the relationship between their rotational speed and thrust. SolidWorks was used to model the single-thruster and PFP prototype, and Ansys Fluent was used to solve the Reynolds-averaged Navier–Stokes equations to obtain the hydrodynamic characteristics of both the thruster and PFP prototype. A comparative analysis of the experimental and simulated hydrodynamic results showed the following: (1) the flow velocity between the blade suction surface and pressure surface tended to decrease, and the pressure tended to increase; (2) the thrust of both the single-thruster and PFP prototype increased with the thruster rotational speed according to a quadratic polynomial relationship; (3) the thrust ratio between the PFP prototype and the combined thrust of the two thrusters under the no-load condition exhibited a logarithmic relationship with the increasing rotational speed; and (4) to meet the operational requirements of the PFP prototype with a working duration exceeding 350 min and a minimum thrust of 20 N, the recommended rotational speed range for the thrusters on the PFP prototype was 1569–1970 rpm. The results of this study provide a fundamental reference for the further optimization of the PFP configurations.

Effect of Stevia rebaudiana stem waste extract on lipid oxidation of salted-dried Pacific saury during chilled storage

Lipid oxidation is the major form of deterioration in salted-dried fish during storage. We here studied the use of Stevia rebaudiana stem (SRS) waste for impeding lipid oxidation of salted-dried Pacific saury fillets during chilled storage. Compared with Vitamin C (VC), the SRS extract (0.2%) significantly delayed lipid oxidation of the salted-dried fish, as determined through assays of the peroxide value, conjugated diene, thiobarbituric acid reactive substances, and acid value; VC is commonly used in salted-dried products. The color results further confirmed the feasibility of the SRS extract in maintaining the quality of the salted-dried Pacific saury fillets. The antioxidant mechanism studies unveiled that the SRS extract exhibited a higher Fe2+-chelating ability than VC, whereas the extract exhibited lower DPPH and ABTS radical-scavenging abilities than VC. This indicated that the high efficacy of the SRS extract in retarding lipid oxidation may be attributable to its higher Fe2+-chelating ability. The in situ Fe2+-chelating assay conducted using confocal laser scanning microscopy further confirmed this conclusion. Potential functional phenolic compounds in the SRS extract were then profiled using the LC-MS method. The SRS waste extract can thus be applied as a natural antioxidant for delaying lipid oxidation of salted-dried fish.

Draft genome sequence and tissue expression panel of Pacific saury (Cololabis saira).

Pacific saury (Cololabis saira) is an important fish in several countries. Notably, the catch of this fish has markedly decreased recently, which might be due to environmental changes, including feeding habitat changes. However, no clear correlation has been observed. Therefore, the physiological basis of Pacific saury in relation to possible environmental factors must be understood. We sequenced the genome of Pacific saury and extracted RNA from nine tissues (brain, eye, gill, anterior/posterior guts, kidney, liver, muscle, and ovary). In 1.09 Gb assembled genome sequences, a total of 26,775 protein-coding genes were predicted, of which 26,241 genes were similar to known genes in a public database. Transcriptome analysis revealed that 24,254 genes were expressed in at least one of the nine tissues, and 7,495 were highly expressed in specific tissues. Based on the similarity of the expression profiles to those of model organisms, the transcriptome obtained was validated to reflect the characteristics of each tissue. Thus, the present genomic and transcriptomic data serve as useful resources for molecular studies on Pacific saury. In particular, we emphasize that the gene expression data, which serve as the tissue expression panel of this species, can be employed in comparative transcriptomics on marine environmental responses.

On the probable distribution of stock-recruitment resilience of Pacific saury (Cololabis saira) in the Northwest Pacific Ocean

Abstract Determining how resilient a stock-recruitment relationship is to environmental variation is crucial for fisheries management. Steepness is a key factor characterizing the resilience of a fish stock and, hence, for establishing management reference points. This study estimates the distribution of steepness for Pacific saury using a simulation approach based on evolutionary ecology and reproductive biology, and how it changes in response to environmental change. The median estimated steepness is 0.82 (80% probable range 0.59, 0.93) based on the best available biological information, which suggests that Pacific saury can produce a relatively high proportion of unfished recruitment when depleted to 20% of unfished spawning biomass. Elasticity analysis indicates that steepness for Pacific saury is most sensitive to the survival rate of early life stages, mean body weight, growth, and length-at-maturity. Environmental change could substantially impact steepness, with unfavorable conditions related to survival rates, length-at-maturity, mean body weight, and growth potentially leading to a reduction in resilience. Understanding these impacts is crucial for the assessment and management of Pacific saury. Our numerical simulation approach provides an analytical tool applicable for calculating the steepness distribution in other small pelagic fish influenced by increases in sea surface temperature due to global warming.

Enhanced stability and antibacterial efficacy of edible oleogels-in-water high internal phase emulsions prepared from soybean lipophilic protein

Recently, convenience-driven consumers have increasingly embraced prepared aquatic foods, facilitating a significant shift within the food industry. However, this change has presented a challenge for maintaining the quality of aquatic products in prepared food items since aquatic products are highly susceptible to microbial contamination during processing or storage. Herein, smart oleogels-in-water high internal phase emulsions (GHIPEs) stabilized solely by soybean lipophilic protein (LP) were prepared via oil phase gelation induced by glycerol monolaurate (GML). The purpose of this system is to act as an effective carrier and facilitate the precise release of thyme essential oils to extend the shelf life of food products. The gelation of the oil phase has significantly enhanced the stability of GHIPEs when compared to traditional HIPEs. When the GML reached 2%, the GHIPEs retained up to 87.18% ± 4.23 of thyme essential oil after 14 d. Moreover, the highest antioxidant potential of GHIPEs (with 2% GML) was confirmed through DPPH and ABTS free radical scavenging assays. Furthermore, the GHIPEs can release thyme essential oil in response to microbial growth, demonstrating their “smart sensing and targeted release” ability. Ultimately, the application of the GHIPEs in the preservation of Cololabis saira significantly reduced the total colony count, pH, TVB-N, and TBARS values (P < 0.05). Consequently, a ready-to-eat Cololabis saira product with an extended shelf life of 7 d at 4 °C was successfully realized, indicating the effectiveness of GHIPEs in preserving seafood freshness. These findings offer novel approaches to maintaining the freshness of prepared aquatic foods.

Chromosomal DNA sequences of the Pacific saury genome: versatile resources for fishery science and comparative biology.

Pacific saury (Cololabis saira) is a commercially important small pelagic fish species in Asia. In this study, we conducted the first-ever whole genome sequencing of this species, with single molecule, real-time (SMRT) sequencing technology. The obtained high-fidelity (HiFi) long-read sequence data, which amount to ~30-folds of its haploid genome size that was measured with quantitative PCR (1.17 Gb), were assembled into contigs. Scaffolding with Hi-C reads yielded a whole genome assembly containing 24 chromosome-scale sequences, with a scaffold N50 length of 47.7Mb. Screening of repetitive elements including telomeric repeats was performed to characterize possible factors that need to be resolved towards 'telomere-to-telomere' sequencing. The larger genome size than in medaka, a close relative in Beloniformes, is at least partly explained by larger repetitive element quantity, which is reflected in more abundant tRNAs, in the Pacific saury genome. Protein-coding regions were predicted using transcriptome data, which resulted in 22,274 components. Retrieval of Pacific saury homologs of aquaporin (AQP) genes known from other teleost fishes validated high completeness and continuity of the genome assembly. These resources are available at https://treethinkers.nig.ac.jp/saira/ and will assist various molecular-level studies in fishery science and comparative biology.

Screening of fish oil fatty acids for antihyperlipidemic activity based on network pharmacology and validation of synergistic efficacy in vitro

Fish oil, rich in docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), shows promise as an anti-hyperlipidemic agent. We explored the synergistic lipid-lowering effects between long-chain monounsaturated fatty acids, EPA, and DHA using network pharmacology and experimental validation in HepG2 cells. Various fish oils, particularly Engraulis japonicus and Pacific saury, effectively reduced oleic acid-induced lipid accumulation. Network pharmacology identified 64 potential targets for fish oil fatty acids' synergistic anti-hyperlipidemic action. Validation revealed their superior impact on upregulating CPT1A and RXRA mRNA, promoting lipid metabolism, and suppressing SCD and FABP1 mRNA, inhibiting lipid synthesis. This combination also reduced IL6 expression, maintaining lipid homeostasis. Activating AMPK and PPAR pathways, it achieved lipid-lowering effects. These findings highlight the potential of fish oil fatty acids for anti-hyperlipidemic interventions, offering a novel research perspective.

Use of the raw material base of marine fish in Russian waters of the Far Eastern seas and adjacent areas of the open part of the Pacific Ocean in 2000–2020

The purpose of the work: characteristics of the raw material base of marine fish in the Far Eastern fishery basin and an assessment of the effectiveness of its use by domestic fisheries at the present stage (2000–2020).Methods used: to achieve this goal, data on biomass, catch and development of the main commercial marine fish were analyzed. Fish catches were reviewed based on operational information about the fishery based on daily ship reports from the industry monitoring system.Novelty: elements of novelty are generalized modern materials on biomass, catch and development of marine fish resources in the Far Eastern seas and adjacent waters of the Pacific Ocean. The current state of commercial fish stocks (walleye pollock, Pacific cod, saffron cod, Pacific herring, Righteye flounders, greenlings, Japanese pilchard, Chub mackerel, Pacific saury) in the Far Eastern fishing basin can be characterized as stable, and the distribution of the catch of these objects among individual fishing areas due to their significant volumes is practically determines the distribution of catch of both quota and non-quota species of marine fish. Scientific information support for the above-m entioned fish is at a high level, their biological condition is generally favorable, and the dynamics of their numbers is regulated mainly by habitat variability.Practical significance: the results of this study can be used in forecasting the dynamics of aquatic biological resources, and the results obtained on marine fish stocks and fisheries will improve the efficiency of using their raw material base.

Different growth patterns reveal the potential origins of two Pacific saury (Cololabis saira) groups in the northwest Pacific Ocean

Identification of stock composition is essential for fish stock assessment and management. Previous studies have suggested that a mixed stock composition of Pacific saury Cololabis saira exists in the northwest Pacific Ocean, but the origins of the stock’s components are poorly understood. We analyze the otolith microstructure of Pacific saury collected in high-seas fishing grounds from June–November, 2016–2019, and estimate hatch date and reconstruct otolith growth trajectory before hyaline zone formation. Results confirm that Pacific saury recruiting to the high-seas fishing ground are mainly from a winter-spawned cohort, secondarily from an autumn-spawned cohort, but also with a small proportion from a spring-spawned cohort. Ages of medium (knob length 240–280 mm) and large (knob length > 280 mm) individuals are mainly 8–12 and 18–21 months, respectively. Two growth patterns are reported for individuals with different otolith growth axes in their early life stages. Each year, unsupervised random forest clustering analysis of otolith daily increment widths reveals two Pacific saury groups. One group, with younger age and a later hatching period, shows a consistently higher growth rate than the other, suggesting that the two groups have different hatch dates and locations. These findings permit more accurate prediction of Pacific saury recruitment, and improve the understanding of short-term stock fluctuations to enable more sustainable management of fisheries.

Identification of novel angiotensin converting enzyme (ACE) inhibitory peptides from Pacific saury: In vivo antihypertensive effect and transport route

Nature food-derived angiotensin converting enzyme inhibitory peptides (ACEIPs) can be potent and safe therapeutics for many medical illnesses, particularly hypertension. In this study, novel ACEIPs were screened and identified from Pacific saury by bio-activity guided approach through ultrafiltration membrane, Sephadex G-25 and RP-HPLC. The antihypertensive effect of ultrafiltration fraction was confirmed with spontaneous hypertensive rats' (SHRs) model. The peptides sequences of which gave the best activity was identified by Q-Orbitrap-MS/MS and selectively synthesized based on the binding energy of molecular docking. Five peptides VVLASLK, LTLK, LEPWR, ELPPK and LPTEK were synthesized, and the peptide LEPWR (IC50 = 99.5 μM) showed the best ACE inhibitory ability. Furthermore, LEPWR against ACE in a mixed competitive pattern and formed six hydrogen bonds with ACE. Additionally, the apparent permeability coefficient (Papp) of LEPWR was 3.56 ± 0.14 × 10−6 cm/s and paracellular transport across tight junctions was the main pathway across the Caco-2 monolayer. Therefore, the Pacific saury is a good material to prepare ACEIPs, but antihypertensive mechanism of peptide LEPWR on SHRs needs further investigation.

Spatiotemporal variations and influential factors affecting reproductive dynamics of Pacific saury in the Northwest Pacific during fishing season.

This study examined the spatial and monthly variations in reproductive dynamics of Pacific saury collected in the high sea (40°N-49°N, 149°E-168°E) of the northwestern Pacific during the fishing season of the Taiwanese stick-held dip-net fisheries (July-November) from 2018 to 2019. Generalized additive mixed-effects models (GAMMs) were applied to explore the relationship between the probability of maturing and spawning occurrence (PMOS ) and the explanatory variables (month, body length, sea-surface temperature [SST] as fixed effects, and fishing set as a random effect) for the age 0 and age 1 fish, respectively. In addition, the impact of the geographical difference in growth rates of age 0 fish, quantified as the radius of the otolith annual ring, on the PMOS of age 1 fish was explored in the GAMMs. Results showed that the mean values of the condition factor (CF) varied by months, and higher mean CFs were observed north of 45°N. However, the mean values of the gonado-somatic index did not show a clear spatiotemporal pattern. The spatial distribution of the ovarian maturation states revealed that the spawning ground of Pacific saury during July-November was broader than that previously known and had partly overlapped with the high-sea fishing ground. The best GAMM showed that the predicted PMOS of the age 0 fish were generally low (mean = 19%, standard deviation [SD] = 10%) and tended to increase with increasing body length. In contrast, the predicted PMOS were relatively higher (mean = 37%, SD = 10%) for the age 1 fish and increased with increasing SST and decreasing latitude. Two candidate GAMMs, which are equally supported as the best model (ΔAIC < 2), provide evidence that a higher growth rate of age 0 fish may result in higher reproductive activity in age 1 fish. This is one of few studies focusing on the reproductive dynamics of Pacific saury during the fishing season; current limitations, future directions, and conservation implications were discussed.

A sea urchin-shaped nanozyme mediated dual-mode immunoassay nanoplatform for sensitive point-of-care testing histamine in food samples

Rapid detection of histamine remains a challenge due to the complexity of food matrices. Based on the high peroxidase-like activity of sea urchin-shaped Pt@Au NPs (SU-Pt@Au NPs), a novel dual-mode nanoplatform is developed for the sensitive detection of histamine utilizing an indirect competitive enzyme-linked immunosorbent assay. According to the colorimetric-based UV–vis nanoplatform, histamine is sensitively detected with a liner range from 0.5 to 100 ng/mL and a limit of detection (LOD) as low as 0.3 ng/mL. Then, a smartphone-loaded color picker APP can intelligently detect histamine in point-of-care testing (POCT) based on the R/B ratio of the color channels, with a detection range of 0.5 to 1000 ng/mL and a LOD as low as 0.15 ng/mL, significantly expanding the detection range. Such an easy-to-use and sensitive detection system is employed to quantify histamine in Pacific saury, crab, and pork samples, indicating outstanding application potential in protein-rich meat food safety.

Length−Length and Length−Weight Relationships of Pacific Saury, Cololabis saira (Scomberesocidae), in the Northwestern Pacific Ocean

Length−Length and Length−Weight Relationships of Pacific Saury, Cololabis saira (Scomberesocidae), in the Northwestern Pacific Ocean