Cobia Research Articles

Genome-wide characterization of microsatellites in cobia Rachycentron canadum (Linnaeus, 1766): Survey and analysis of their abundance and diversity.

The cobia Rachycentron canadum, mainly distributed in the warm waters of tropical and subtropical regions around the world, remains a fish of considerable economic importance. Detailed diversity and the number of microsatellite sequences in the cobia genome are still unintelligible. The primary aim of this work was to identify and quantify the miscellaneous SSR sequences in the cobia genome. More than 280,000 sequences were sequenced and screened using next-generation sequencing technology and microsatellite identification. Perfect mononucleotide repeats, dinucleotide microsatellites, and trinucleotide microsatellites contain (A)10 /(T)10 , (AC)6 /(TG)6 , and (AAT)5-32 as the largest number of motifs in each type of microsatellite, respectively. The tetranucleotide and pentanucleotide microsatellites (TTM and PTM) consist of the largest number of motifs of both (ATCT)5-32 and (TCAT)5-31 in TTMs, and (CTCTC)5-9 in PTMs, whereas the hexanucleotide microsatellites are rarely observed in the cobia genome. All c. 38000 sequences of composite microsatellites are extremely diverse, including compound (11.71%), interrupted compound (71.77%), complex (0.45%), and interrupted complex (16.07%). In this study, we developed a convenient and useful recording system for writing down and categorizing diverse composite microsatellite types. This system will provide great support for exploring repeat origins, evolutionary mechanisms, and the application of polymorphic microsatellites.

Feed Regime Slightly Modifies the Bacterial but Not the Fungal Communities in the Intestinal Mucosal Microbiota of Cobia Fish (Rachycentron canadum).

The bacterial community of the intestinal microbiota influences many host functions, and similar effects have been recently reported for the fungal community (mycobiota). Cobia is a tropical fish that has been studied for its potential in marine aquaculture. However, the study of its bacterial community has been underreported and the mycobiota has not been investigated. We analyzed the gut bacterial and fungal profile present in the intestinal mucosa of reared adult cobias fed two diets (frozen fish pieces (FFPs) and formulated feed (FF)) for 4 months by sequencing the 16S rRNA (V3-V4) and internal transcribed spacer-2 (ITS2) regions using Illumina NovaSeq 6000. No significant differences in the alpha diversity of the bacterial community were observed, which was dominated by the phyla Proteobacteria (~96%) and Firmicutes (~1%). Cobia fed FF showed higher abundance of 10 genera, mainly UCG-002 (Family Oscillospiraceae) and Faecalibacterium, compared to cobia fed FFPs, which showed higher abundance of 7 genera, mainly Methylobacterium-Methylorubrum and Cutibacterium. The inferred bacterial functions were related to metabolism, environmental information processing and cellular processes; and no differences were found between diets. In mycobiota, no differences were observed in the diversity and composition of cobia fed the two diets. The mycobiota was dominated by the phyla Ascomycota (~88%) and Basidiomycota (~11%). This is the first study to describe the gut bacterial and fungal communities in cobia reared under captive conditions and fed on different diets and to identify the genus Ascobulus as a new member of the core fish mycobiota.

Effect of feeding restrictions on development of juvenile cobias, Rachycentron canadum

Aim of study: A 45-day trial was conducted to evaluate fasting as a possible way of food strategy during production of juvenile cobias (Rachycentron canadum). Area of study: The study was conducted in the State of Espírito Santo, Brazil. Material and methods: The following different protocols were used to organize their feeding: C, fish fed to satiety twice a day for 45 days; U1, fish fed to satiety twice a day on alternate days; U2, fish fed to satiety twice daily for five consecutive days, followed by two days of food deprivation, cyclically; U5, fish subjected to food deprivation for five days and then fed to satiety twice a day for 40 days; U10, fish subjected to food deprivation for ten days and then fed to satiety twice a day for 35 days; and U15, fish subjected to food deprivation for fifteen days and then fed to satiety twice a day for 30 days. Main results: No mortality was observed during the trial period. The different feeding protocols significantly affected juvenile cobias development and wellbeing. The final weight (g) of cobia juveniles was C – 91.9 ± 9.1; U1 – 75.0 ± 11.2; U2 – 72.2 ± 6.0; U5 – 70.3 ± 6.1; U10 – 63.4 ± 4.6; U15 – 54.4 ± 4.7. No compensatory growth was observed during the entire experimental period. Research highlights: Continuous fasting had a more severe effect than intermittent fasting. Significantly greater hepatocyte counts were correlated with longer fasting periods. Fasting protocols should not be recommended for juvenile cobias.

Genome−wide expression profile analysis of the NHE and NKA gene family in Rachycentron canadum (Linnaeus, 1766) and its response to salinity adaptation

Genome−wide expression profile analysis of the NHE and NKA gene family in Rachycentron canadum (Linnaeus, 1766) and its response to salinity adaptation

Phenotypic Variability in Dorsal-fin Rays of Rachycentron canadum (Linnaeus, 1766) from Western, Visayas, Philippines

Cobia, Rachycentron canadum, is the only species in the family of Rachycentridae. Cobia is typically characterized as having 26–33 dorsal-fin rays. However, an investigation of specimens collected from Western Visayas waters revealed a wider variation in dorsal-fin ray count than previously reported, with some specimens having 35–36 dorsal-fin rays. Suspecting a possible cryptic species, we compared the mitochondrial cytochrome oxidase subunit 1 (COI) sequence for specimens with 35–36 dorsal-fin rays with those having the more typical 26–33 dorsal-fin rays. The sequences revealed no genetic differences between the two morphs. Morphometric measurements and meristic counting likewise found no significant differences. This is the first report of phenotypic variability in the dorsal-fin rays in Cobia. As a result of the phenotypic and genotypic characterization presented in this work, fisheries scientists and ichthyologists will be more aware of the existence of phenotypic variability in Cobia.

Elevated sea temperature combined with dietary methionine levels affect feed intake and appetite-related neuropeptide expression in the brains of juvenile cobia (Rachycentron canadum)

This study aimed to determine the impact of elevated temperature combined with different levels of dietary methionine concentrations on feed intake (FI) and brain expression of selected neuropeptides and one receptor involved in appetite control in juvenile cobia (approximately 3.7 g body weight). The genes studies were neuropeptide y, npy; agouti-related protein, agrp; cocaine- and amphetamine-regulated transcript, cart; cholecystokinin, cck and melanocortin 4 receptor; mc4r. The cobia were reared at typical sea water temperature in Vietnam (30 °C) and elevated temperature (34°C; selected as one of the predicted scenarios of climate change). The fish were fed diets with different levels of methionine: deficient (M9; 9.1 g/kg), sufficient (M12; 12.8 g/kg) and surplus (M16, 16.8 g/kg) for 6 weeks (triplicate tanks per treatment). Both dietary methionine concentration and temperature affected FI in cobia. Dietary methionine deficiency (i.e., M9) and elevated temperature reduced FI in cobia. Temperature significantly influenced the mRNA expression of agrp, cart, cck and mc4r. Expression of the orexigenic neuropeptide npy was consistently higher before the meal than after the meal for all diets and at both temperatures. At 30°C, prefeeding levels of npy correlated with both increased methionine levels and FI. The interaction between dietary methionine and temperature on the levels of brain npy expression was significant (P<0.05). There was higher brain expression of agrp, cart and cck in cobia at 34°C than in fish at 30°C, which was correlated with a lower FI. In conclusion, both feeding, temperature and/or dietary methionine levels affected the brain expression of npy and agrp, cart, cck and mc4r. This suggests that these neuropeptides as well as the mc4r receptor are actively involved in adjusting feed intake to compensate for changing energetic demands, as well as metabolic adjustments due to the variable availability of methionine at elevated temperature.

Modulation of immune genes in the mucosal-associated lymphoid tissues of cobia by Sarcodia suae extract.

Rachycentron canadum (cobia) is a marine fish species of high economic value in aquaculture due to its fast growth rate and good feed conversion efficacy. Regrettably, the industry has been affected by significant setbacks from high mortality due to diseases. Consequently, an improved perception of innate immunity correlated to each mucosal-associated lymphoid tissue (MALT) in teleost fish is necessary to understand hosts' response towards infections better. The utilization of polysaccharides in seaweed to stimulate the immune system has gathered unprecedented attention. The present study examined the immunostimulatory effects of Sarcodia suae water extracts (SSWE) on in vivo gill-, gut- and skin-associated lymphoid tissues (GIALT, GALT, and SALT) via immersion and oral ingestions. The GIALT genes (TNF-α, Cox2, IL-1β, IL-6, IL-8, IL-17A/F1-3, IL-11, IL-12, IL-15, IL-18, MHCIa, IgM, and IgT) except IL-10 recorded positive upregulations in a dose-dependent manner post 24h immersion in SSWE, indicating the algae extract contained bioactive compounds that could stimulate the immune genes. The upregulation of IL-12, IL-15, and IL-18 in the gills and hindgut post-SSWE immersion indicated that the extract could promote Th1-related responses in the MALTs. The modulation of immune gene expressions in the feeding trial was less potent than in the SSWE immersion. These findings indicated that the SSWE stimulated robust immune responses in both the GIALT and GALT of cobia. This suggests that the SSWE could be further explored as an effective immersive stimulant for fish, enhancing their immune system against pathogens.

Human health risk assessment due to consumption of dried fish in Chennai, Tamil Nadu, India: a baseline report.

The current study sought to determine the levels of radioactivity and heavy metal contamination in 22 dried fish samples collected in Chennai, Tamil Nadu. The study found that there were substantial heavy metals concentrations for Pb, Mn, Cr, Co, and Cd. The concentration of heavy metal Pb being alarmingly high (32.85 to 42.09mg/kg), followed by Cd (2.18mg/kg to 3.51mg/kg) than the permissible limit of WHO (2.17mg/kg) for Pb and (0.05mg/kg) for Cd. In terms of radioactivity, the gross alpha activity in the dried fish samples ranged 6.25 ± 0.12 to 48.21 ± 0.11 Bg/kg with an average of 20.35 Bg/kg and with a gross beta activity from 6.48 ± 0.02 to 479.47 ± 0.65 Bg/kg, for an average of 136.83 Bg/kg. The study found that the internal radiation dose that people receive upon consuming the fish species Sphyraena obtusata, Rachycentron canadum, Lepidocephalichthys thermalis, Synodontidae, Carangoides malabaricus, Sardina pilchardus, Scomberomorus commerson, Sillago sihama, Gerres subfasciatus, and Amblypharyngodon mola is above the ICRP-recommended limit of less than 1mSv/year. Annual gonadal dose equivalent (AGDE) and total excessive lifetime cancer risk (ELCR) ranged 0.488 µSv year-1 and 0.004 µSv year-1 respectively, the values of AGDE being higher than the global average value. The findings of the study indicate that the analyzed dried fish samples are contaminated with Pb and Cd, which shall pose cancer risk to the consumers as a result.

Dietary Wheat Gluten Alters the Gut Microbiome and Plasma Taurine Levels in European Sea Bass (Dicentrarchus labrax)

Incorporating environmentally sustainable plant-based protein sources into aquafeeds is a priority for the aquaculture industry. Wheat gluten as a plant protein source has been successfully integrated into feeds for several fish species. However, unique nutritional requirements and the potential for intolerances necessitate the evaluation of plant-based diets by species. Previous work by our laboratory indicated that wheat gluten at less than 4% inclusion in a compound feed had a negative impact on growth and survival rate in juvenile cobia (Rachycentron canadum). In the current study, we evaluated the effects of wheat gluten inclusion in a plant-based diet in juvenile European sea bass (Dicentrarchus labrax). No major differences were observed in terms of growth rate, plasma biochemical parameters, detectable induction of plasma IgM, IgT, or factors capable of binding gliadin in response to the inclusion of 4% dietary wheat gluten. However, plasma levels of taurine doubled in the fish fed wheat gluten, and there were considerable changes to the intestinal microbiome. Despite these measurable changes, the data suggest that dietary inclusion of 4% wheat gluten is well tolerated by juvenile European sea bass in a plant-based feed formulation.

Post-feeding Molecular Responses of Cobia (Rachycentron canadum): RNA-Sequencing as a Tool to Evaluate Postprandial Effects in Hepatic Lipid Metabolism.

We used transcriptome sequencing to investigate the hepatic postprandial responses of Rachycentron canadum (cobia), an important commercial fish species. In total, 150 cobia juveniles (50 per tank, triplicate) were fed ad libitum with a commercial diet for 7days, fasted for 24h, and fed for 10min. The liver was sampled 10min prior to feeding and 30min, 1, 2, 4, 8, 12, and 24h after the feeding event. Each sample was evaluated in terms of liver fatty acid profile and gene expression. Differential gene expressions were evaluated, focusing on fatty acid synthesis and oxidation pathways. In general, the liver fatty acid profile reflected diet composition. Docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) levels increased at 8 to 12h but decreased at 24h after the feeding event. A high number of differentially expressed genes (DEGs) were observed comparing fish that fasted for 8h with those fasted for 30min and 24h, while a reduced number of DEGs was observed comparing individuals who fasted for 30min compared with those who fasted for 24h. Similarly, the main differences in the expression of genes related to the fatty acid biosynthesis and oxidation pathways were noticed in individuals who fasted for 8h compared with those who fasted for 30min and 24h. The results suggested that the adequate time to sample the individuals ranged between 8 and 12h after the meal since, apparently, after 24h, differential gene expression was not necessarily influenced by food intake.

Restricted connectivity for cobia Rachycentron canadum (Perciformes: Rachycentridae) in the Western Atlantic Ocean

AbstractCobia (Rachycentron canadum) is a coastal pelagic migratory fish species of tropical and subtropical waters, where it is an important game fish and it has been commercially expanded in offshore aquaculture systems. Understanding population connectivity is of utmost importance to the sustainable use and conservation of aquatic resources, and information on genetic diversity and structure is key element in unraveling differentiation when no clear physical barriers exist. In the present study, cobia genetic diversity and structure were depicted using mitochondrial DNA cytochrome b sequencing and microsatellite genotyping in samples from the Southwestern Atlantic and showed that a major single population inhabits the southern hemisphere. Cytochrome b sequencing also suggested that the Indian Ocean is the center of origin for this species' diversification. A hierarchical analysis of AMOVA compared sampling locations from the Northwestern Atlantic (from a previous study) with the Southwestern ones using nine shared microsatellite markers. Differentiation among groups (FCT = 0.41), Bayesian clustering analysis, and complementary ordination analyses (by discriminant analysis of principal components [DAPC] and factorial correspondence analysis [3D‐FCA]) presented a clear separation between the two hemispheres, supported by a Lagrangian model that explained the ocean dynamics over larval retention on the Western Atlantic. Another genetic subgroup intermingled with the main Southwestern group may also exist further south, probably associated with the Vitória‐Trindade Ridge and the local current systems. The distribution of this species in metapopulations is of extreme relevance for fisheries and fish hatcheries management in the Atlantic Ocean.

Comparative gonad transcriptome analysis in cobia (Rachycentron canadum).

Background: Cobia (Rachycentron canadum) is a species of fish with high commercial potential particularly due to fast growth rates. The evidence of sexual size dimorphism favoring females indicate potential benefits in having a monosex culture. However, the involvement of genetic factors responsible for sexual development and gonadal maintenance that produces phenotypic sex in cobia is largely unknown. Methods: In the present study, we performed transcriptome sequencing of cobia to identify sex-biased significantly differentially expressed genes (DEGs) in testes and ovaries. The reliability of the gonad transcriptome data was validated by qPCR analysis of eight selected significantly differential expressed sex-related candidate genes. Results: This comparative gonad transcriptomic analysis revealed that 7,120 and 4,628 DEGs are up-regulated in testes or ovaries, respectively. Further functional annotation analyses identified 76 important candidate genes involved in sex determination cascades or sex differentiation, including 42 known testis-biased DEGs (dmrt1, amh and sox9 etc.), and 34 known ovary-biased DEGs (foxl2, sox3 and cyp19a etc.). Moreover, eleven significantly enriched pathways functionally related to sex determination and sex differentiation were identified, including Wnt signaling pathway, oocyte meiosis, the TGF-beta signaling pathway and MAPK signaling pathway. Conclusion: This work represents the first comparative gonad transcriptome study in cobia. The putative sex-associated DEGs and pathways provide an important molecular basis for further investigation of cobia's sex determination, gonadal development as well as potential control breeding of monosex female populations for a possible aquaculture setting.

Selection of Autochthonous Yeasts Isolated from the Intestinal Tracts of Cobia Fish (Rachycentron canadum) with Probiotic Potential

Some yeast strains have been proposed as probiotics to improve the health of cultured fish. Cobia is a tropical benthopelagic fish species with potential for marine aquaculture; however, one of the main limitations to its large-scale production is the high mortality of fish larvae. In this study, we evaluated the probiotic potential of autochthonous yeasts from the intestines of cobia. Thirty-nine yeast isolates were recovered from the intestinal mucosa of 37 adult healthy cobia by culture methods. Yeasts were identified by sequencing of the ITS and D1/D2 regions of the 28S rRNA gene and typed by RAPD-PCR using the M13 primer. Yeast strains with unique RAPD patterns were characterized in terms of their cell biomass production ability; anti-Vibrio, enzymatic, and hemolytic activity; biofilm production; hydrophobicity; autoaggregation; polyamine production; safety; and protection of cobia larvae against saline stress. Candida haemuloni C27 and Debaryomyces hansenii C10 and C28 were selected as potential probiotics. They did not affect the survival of larvae and showed biomass production >1 g L-1, hydrophobicity >41.47%, hemolytic activity γ, and activity in more than 8 hydrolytic enzymes. The results suggest that the selected yeast strains could be considered as potential probiotic candidates and should be evaluated in cobia larvae.

Full-length transcriptome from different life stages of cobia (Rachycentron canadum, Rachycentridae)

Cobia (Rachycentron canadum, Rachycentridae) is one of the prospective species for mariculture. The transcriptome-based study on cobia was hampered by an inadequate reference genome and a lack of full-length cDNAs. We used a long-read based sequencing technology (PacBio Sequel II Iso-Seq3 SMRT) to obtain complete transcriptome sequences from larvae, juveniles, and various tissues of adult cobia, and a single SMRTcell generated 99 gigabytes of data and 51,205,946,694 bases. A total of 8609435, 7441673 and 9140164 subreads were generated from the larval, juvenile, and adult sample pools, with mean sub-read lengths of 2109.9, 1988.2 and 1996.2 bp, respectively. All samples were combined to increase transcript recovery and clustered into 35661 high-quality reads. This is the first report on a full-length transcriptome from R. canadum. Our results illustrate a significant increase in the identified amount of cobia LncRNAs and alternatively spliced transcripts, which will help improve genome annotation. Furthermore, this information will be beneficial for nutrigenomics and functional studies on cobia and other commercially important mariculture species.

Hematological Response of Juvenile Cobia to Three Anesthetics

Optimal concentrations of three anesthetics for use with juvenile cobia (Rachycentron canadum) were determined using time-to-recovery and hematological datasets. Buffered MS-222, clove oil and 2-phenoxyethanol (2-PE) were examined. Juvenile cobia were exposed to three concentrations of each anesthetic at 24 °C. Based on time to recovery, optimal doses for MS-222 was determined as 120-mg L−1, that for 2-PE, 0.4-mL L−1 and, for clove oil, 5-mL L−1. The hematological response of cobia to anesthesia included quantification of whole blood pH, pCO2, pO2, and Ca2+, K+, Na+, Cl−, hematocrit and glucose. Irrespective of anesthetic employed, cobia expressed metabolic acidosis, with changes in blood pH (p < 0.001) being matched by increases (p < 0.001) in pCO2. Anesthesia tended to increase blood Na+, hematocrit, pO2, Ca2+, and K+ although differential responses between anesthetics were recorded, suggesting different modes of action. A combination of recovery and hematological data indicated that when anesthesia is necessary, MS-222 represents the sedative of choice.

Changes in mineral content and vitamin A of cobia (Rachycentron canadum) due to the steaming process

Cobia (Rachycentron canadum) is a commodity that has the potential to be cultured, but little information about the nutritional content of those fish. This study aimed to determine the effect of the steaming process on the chemical composition, mineral, and vitamin A of cobia from Balai Besar Pengembangan Budidaya Laut Lampung. Steaming lowered the chemical composition of cobia meat including moisture content, ash, fat, and protein on a dry based. The steaming process affected the decreasing vitamin A, and minerals content (calcium, sodium, phosphorus, magnesium, and zinc) and showed no effect on iron and potassium content. The highest mineral loss happened after steaming to magnesium (140 mg/100 g) and the lowest one was iron (0.004 mg/100 g). Steaming lowered the vitamin A content of cobia meat up to 42.36%.

Determination of biological parameters of 4 marine fish species (sea bass, cobia, orange-spotted grouper, and short yellowfin pompano) for assessment of the holding capacity of a location

A biochemical experiment on four marine fish species commonly farmed in Vietnam, sea bass Lates calcarifer(Bloch, 1790), cobia Rachycentron canadum (Linnaeus, 1766), orange-spotted grouper Epinephelus coioides(Hamilton, 1822), and short yellowfin pompano Trachinotus ovatus (Linnaeus, 1758), was carried out at Cat Ba island, Hai Phong province. The mean weight of fish used in the experiment were 2, 5, 2, and 0.6 kg.ind-1, respectively. The experiment aimed to determine the biological parameters of the farmed fish (Ap, Af, Ac) and related nutritional parameters (Pp, Pf, Fp, Ff, Fc), for assessment of the holding capacity of a location. The results showed that the apparent digestibility coefficient of protein and fat in trash fish for sea bass were 92.90%, 93.84%, respectively; cobia 91.17%, 95.53%; orange-spotted grouper 95.20%, 96.40%. The apparent digestibility coefficient of protein, fat and carbohydrate in pellet feed for short yellowfin pompano were 85.83, 76.47, and 13.68%, respectively. The protein content and fat content in the muscle of sea bass were 19.28%, 6.27%; cobia 19.13%, 13.85%; orange-spotted grouper 17.37%, 7.32%; and short yellowfin pompano 18.31%, 15.08%, respectively. The protein content and fat content of trash fish were 16.99%, 7.19%, respectively. The proportion of protein, fat and carbohydrate of pellet feed were 42.01, 9.93, and 27.82%, respectively. There are no carbohydrates in the muscle of farmed fish as well as trash fish.

Integrating information from semi-structured interviews into management strategy evaluation: A case study for Southeast United States marine fisheries

Management strategy evaluation (MSE) has become a more common tool for engaging stakeholders in fisheries management, and stakeholder participation in MSE is increasingly recognized as a vital component of the process. The participation of stakeholders, specifically fishers, in MSE is of particular importance because they often possess intimate knowledge of the socio-ecological management system that MSE seeks to model. When the resources to conduct a “full” MSE with direct fisher involvement are unavailable, MSEs are sometimes conducted by desk-based analysts with no fisher engagement. We propose an intermediate framework in which information collected from semi-structured interviews is used to inform a “desk-based” MSE. We demonstrate that semi-structured interviews with commercial and recreational fishers can elicit some of the same kinds of information that fishers provide during direct participation in MSE. We conducted 30 semi-structured interviews with commercial and recreational fishers from the Southeast United States participating in either Atlantic cobia (Rachycentron canadum) or black sea bass (Centropristis striata) fisheries. We collected primarily qualitative and some quantitative information about preferred conceptual objectives and management measures, and how their fishing behavior has changed in response to past management action. Commercial fishers generally preferred conceptual objectives and management measures that align with traditional MSY-based fisheries management, while recreational fishers’ responses were substantially more heterogeneous, indicating a more diverse range of desired objectives and preferred management measures. We synthesized this information to develop a suite of management procedures that employ a range of fishing mortality-based constant-catch harvest control rules and size-based management measures for simulation testing against preferred objectives by sector. We demonstrate that integrating information from semi-structured interviews with MSE in this way offers a cost-effective alternative intermediate approach to fisher participation in MSE when direct participation is not possible.

Virginia Game Fish Tagging Program: A Nontraditional Data Source for Fisheries Management

Since 1995, the Virginia Game Fish Tagging Program (VGFTP) has collected data for recreationally important marine fishes in cooperation with skilled volunteers. These trained anglers tagged more than 380,000 fishes since 1995 and contributed data regarding fish movement and site fidelity patterns of species captured and released in the Chesapeake Bay and Atlantic coastal waters. Over time, the VGFTP has become an important source of data for fishery managers and program data are included in stock assessments for species such as Cobia Rachycentron canadum. Best management practices from the VGFTP show that cooperative science programs that collect data for management should have mandatory hands‐on training with quality control mechanisms in place for submitted data. Further, fishery managers, statisticians, and stakeholders should work together to identify the data needs for statistical viability before volunteers start collecting information. Finally, data objectives and project results should be shared with the stakeholders who collected the data, in addition to fishery managers.

Using calcined oyster shell powder as a natural preservative for extending the quality of black king fish (Rachycentron canadum) fillets

AbstractAquacultural foods represent a valuable source of nutrition with high nutritional value and numerous health benefits. They are widely consumed as a palatable and easily digestible source of protein. However, they are highly susceptible to spoilage after harvesting and subsequent processing and storage. Natural and green biological methods for inhibiting or reducing the growth of microorganisms and controlling the quality of products during storage are of particular commercial importance. In this study, black king fish (BKF) fillets treated with calcined oyster shell powder (COSP) exhibited the dual benefits of extended shelf life and natural safety and nontoxicity. In particular, COSP inhibited acid‐producing microorganisms and aerobic bacteria by regulating pH throughout the refrigerated storage of BFK fillets. TVB‐N levels in BFK fillets were maintained below 20 mg/100 g, while peroxide values (PV), thiobarbituric acid reactive substances (TBARS), and trimethylamine (TMA) levels were all within acceptable ranges, all of which were significantly different (p < 0.05) compared to the control group. In addition, the hardness and overall acceptability performance showed significantly favorable results compared to the control group. The results of this study may be widely applicable to aquatic food products. Minimizing postharvest and financial losses in large‐scale aquatic products production by extending shelf life will provide additional economic benefits.Novelty impact statement COSP treatment can inhibit the growth of microorganisms. COSP treatment can control the quality of products during frozen storage. Fish fillets treated with COSP exhibited the benefits extended shelf life and natural safety and nontoxicity.