Fish Meal Research Articles

Effect of dietary supplementation of lauric acid on growth performance, digestive enzymes, serum immune and antioxidant parameters, and intestinal morphology in black sea bream.

An eight-week feeding trial was conducted to examine the impact of dietary supplementation with lauric acid (LA) on juvenile black sea bream. A basal diet was formulated containing 19.9% fish meal, while five additional diets were prepared, each supplemented with varying levels of LA: LA1 (0.01%), LA2 (0.02%), LA3 (0.04%), LA4 (0.08%), and LA5 (0.16%), denoted as LA1 through LA5, respectively. Triplicate tanks were randomly allocated to each diet, each containing 20 fish with an initial weight of 1.55 ± 0.02g. At the conclusion of the trial, the LA3 group exhibited significantly greater final body weight (FBW), weight gain (WG), specific growth rate (SGR), and protein efficiency ratio (PER) compared to the other groups (P < 0.05), while the feed conversion ratio (FCR) was markedly higher in the control group. No significant differences were detected among the groups in terms of initial body weight (IBW), muscle fiber index (MFI), protein productive value (PPV), condition factor (CF), hepatosomatic index (HSI), intraperitoneal fat (IPF), viscerosomatic index (VSI), and survival rate (SR) (P > 0.05). No significant variations were observed among the groups in the proximate compositions of the dorsal muscle and whole body (p > 0.05). Furthermore, no significant differences were observed in serum immune and antioxidant parameters in the midgut and hindgut and digestive enzyme activity (P > 0.05) among the treatment groups. However, the LA3 group demonstrated significantly higher levels of serum immune response markers IgM, C3, and C4 compared to the other groups, while malondialdehyde (MDA) levels were significantly elevated in the control group relative to the others. The LA3 group demonstrated significantly increased fore-intestinal villus height, crypt depth, villus height-to-crypt depth ratio, and goblet cell count per villus compared to the other groups (P < 0.05).

Mortality drives production dynamics of Atlantic cod through 1100 years of commercial fishing.

Most edible fish species have been fished for centuries or millennia, leaving little record or understanding of their population responses prior to human impact and thus no baseline for population conservation. Here, we reconstruct the population dynamics of Atlantic cod, one of the world's most harvested fish species, from the pristine state during the Viking era through more than 1100 years of fishing. Analysis of cod otoliths recovered during archaeological excavations of Icelandic fish processing sites revealed that cod in the 10th to 12th centuries were 25% larger and up to 300% older than modern, despite slower density-dependent growth rates attributed to the sixfold increase in abundance. Fishing mortality came to dominate a time-invariant natural mortality rate and other population characteristics after the 14th century, with minimal evidence of environmental effects at the century scale. Despite the absence of catch records and surveys, biological reference points based on pristine fish populations are now possible where otolith collections are available.

Characterising "obesogenic" versus "protective" food consumption, and their value chain among Ghanaian households.

This paper explores the characteristics of Ghanaian households' consumption of obesogenic versus protective foods, including their retail, distribution, and origin. A household food consumption survey was conducted using an adapted Prospective Urban and Rural Epidemiology study Food Frequency Questionnaire. Product pathways for selected obesogenic (processed meat, Sugar-Sweetened Beverages, and biscuits) and protective (cooked vegetables, legumes, and fish) foods were traced from retailers through distributors/wholesalers to producers. Rural and urban communities in the Ashanti Region and selected retail/wholesale/producers nationwide. 612 households, 209 retailers and 185 wholesalers/distributors. About 20% of households consume Sugar-Sweetened Beverages (SSB) and confectionery weekly, and just 2% consumed processed meat. Of the protective foods, fish had the highest proportion of households consuming weekly (74.5%), followed by cooked vegetables (53.1%) and legumes (22.8%). Frequent SSB consumption is higher in younger (p<0.001), male (p=0.010), urban (p<0.001), and more educated (p<0.001) food purchaser households. Below 10% of households followed the healthiest dietary pattern (high-protective-and-low-obesogenic) but higher in older and more educated food purchaser households. In contrast, most households (about 80%) consumption patterns did not discriminate between obesogenic and protective foods. Generally, characteristics of purchasers from retail/wholesale outlets agree with those of households, where obesogenic foods were retailed to younger, less educated buyers than older, more educated ones. While the protective foods had a strong local producer presence, the obesogenic foods were predominantly imported. Household consumption and retail/distribution of obesogenic foods are associated with socio-demographic characteristics, but obesogenic foods are almost entirely produced outside Ghana. Policies that regulate importation on health grounds can promote a healthier food environment.

Isolation and Characterisation of Acid Soluble Collagens and Pepsin Soluble Collagens from Eel (Anguilla japonica Temminck et Schlegel) Skin and Bone

Eel (Anguilla japonica) is an important and valuable food fish in East Asia and its by-products have been reported to include bioactive and profitable components. This study aimed to extract, characterise, and compare the structure and properties of acid-soluble collagens (ASCs) and pepsin-soluble collagens (PSCs) from the skin and bone of eel (Anguilla japonica), providing insights into their composition, structure, and properties for various applications. The yields of ASC-S (from skin), PSC-S (from skin), ASC-B (from bone), and PSC-B (from bone) were 12.16%, 15.54%, 0.79%, and 1.34% on a dry weight basis, respectively. Glycine, the dominant amino acid, accounted for 16.66% to 22.67% of total amino acids in all samples. SDS-PAGE and FTIR analyses showed the typical triple-helical structure of type I collagen with slight variations in molecular order in extract and intermolecular cross-linking between skin and bone collagens. The denaturation temperature (Tmax1) measured by differential scanning calorimetry (DSC) is 81.39 °C and 74.34 °C, respectively, for ASC-B and ASC-S. Bone collagen has higher thermal resistance than skin collagen. Surface morphology imaged using a scanning electron microscope (SEM) showed that the bone collagen had a denser network structure, whilst the skin collagen was more fibrous and porous. The findings suggest that eel-derived collagens from skin and bone can serve as potential alternatives in the food, cosmetic, and healthcare industries.

Influence of complex feed additive on the microstructure of the spleen of white rats

When assessing the impact of various drugs (including feed additives), information on their effect on the proliferation of cells in the immunogenesis organs is very important. The feed additive was administered orally using an atraumatic probe in the form of a powder suspension for 90 days: the first group of rats served as a control, they were given tap water and compound feed; animals of the second experimental group received tap water with a feed additive in the form of fish meal at a dose of 800 mg / kg; and the third group - at a dose of 600 mg / kg. It was found that when using a complex feed additive (fish meal) in different doses, no significant changes in the clinical status of white rats are observed. Evaluation of the linear values of the rat spleen (length, width, thickness, diameter) showed that they were at the level of control animals. The average body weight of animals in the experimental groups was almost at the level of control rats. It was also found that the change in spleen weight was parallel to the increase in body weight of rats. This characterized their proportional growth and development. According to the results of the study of the histological picture of the spleen, it can be concluded that, despite the different doses of the feed additive, there are no visual changes in the organ at the microstructure level. The studies were conducted as part of the scientific work on the topic "Hygiene of processing biological waste by microbial synthesis."

Food and Feedings of Mystus tengara (Hamilton, 1822) from Nagavali River, Andhra Pradesh, India

Small indigenous fish species perform vital role in indigenous people food habitat and their empowerment. Mystus tengara is a well-known and commonly available food fish species, and one of the candidate ornamental fish species in ornamental fish firms. A total of 145 specimens of Mystus tengara (Hamilton, 1822) species were collected from a small distributary of Nagavali River of Andhra Pradesh. 35 food items were observed in the gut of Mystus tengara. The present study has been performed on the food and feeding habits, Gastro Somatic Index, Relative Length of Gut, Fullness and feeding Intensity, and Gut Content Analysis of Mystus tengara. Present study results very close to the earlier studies and revealed that Mystus tengara is a carnivorous fish and zooplankton is the basic food group for this fish species and observed food and feeding indicating sustainable growth and development in different river environments.

Microplastics in freshwater reservoirs of protected areas on the example of lakes of the «Valdai» National Park

The article deals with the problem of pollution of freshwater reservoirs by micro- and macroplastics arising during the decomposition of plastic waste. Special attention is paid to the appearance of microplastics in lakes of specially protected areas, in particular, in lakes of the Valdai National Park. As a result of reconnaissance studies, microplastic particles were found in lakes used for fisheries and recreational purposes. There is no contamination by polymer microparticles in the lakes of the protected area.Research conducted at the St. Petersburg State University of Marine Sciences shows that microplastic particles are found in most fish food packages, this amount is not large, but over the period of existence of the fishery site, a significant amount of plastic particles accumulates in the water and bottom sediments, which is a source of secondary pollution of the reservoir. As a result of reconnaissance studies, microplastic particles were found in lakes used for fishery and recreational purposes. Only lakes Bolshoe and Maloe Yaichko are free of microplastics, which is due to their protection regime and inaccessibility.

Exploring single cell microbial protein as a sustainable fishmeal alternative in yellowtail kingfish (Seriola lalandi) diets: impacts on health and gut microbiome

BackgroundWith the global expansion of aquaculture and the increasing demand for fish meal, identifying appropriate and sustainable alternative protein sources for aquafeeds has become essential. Single-cell protein (SCP), derived from methanotrophic bacteria, presents a promising alternative by converting methane into protein, potentially addressing both the need for alternative protein sources and reducing industrial greenhouse gas emissions. This study aimed to evaluate the effects of different levels of SCP inclusion (0%, 25%, 50%, and 75% fish meal replacement) on the health, gene expression, and gut microbiome of yellowtail kingfish (YTK, Seriola lalandi) following a 35-day growth trial.ResultsThe study found that SCP inclusion at the highest level of fishmeal replacement (75%) induced a mild inflammatory response in the hindgut of the fish. However, micromorphological assessments of the hindgut, serum biochemistry, and gene expression analyses revealed no significant detrimental effects from SCP replacement. Notably, there were indications of improved lipid digestibility with SCP. Furthermore, SCP inclusion significantly enhanced microbial richness and altered the composition of the gut microbiome, introducing beneficial bacterial taxa that may contribute to improved gut health and resilience.ConclusionsThis study highlights SCP as a viable and sustainable alternative to fish meal in YTK diets. The findings suggest that SCP can be included in YTK diets without adverse health effects at moderate levels and may even offer benefits in terms of lipid digestibility and gut microbiome diversity. These results contribute to the advancement of more sustainable aquaculture practices.

Relationship between blood DNA methylation, diet quality indices and metabolic health: Data from Obekit study.

Epigenetic mechanisms, which can be modulated by dietary factors, have been proposed as a possible factor in understanding interindividual differences in disease susceptibility. We aimed to determine the relationships between DNA methylation (DNAm), diet quality, and metabolic health in Spanish individuals. This is a transversal study encompassing 337 male and female participants in the Obekit study. Diet quality was assessed using a validated semiquantitative food frequency questionnaire and seven previously established scores: overall, healthy and unhealthy Plant-Based Diet Index (PDI, hPDI and uPDI, respectively), dietary diversity score (DDS), unprocessed/minimally processed foods (MPF) and ultra-processed foods (UPF) consumption and Mediterranean diet (MD) score. DNAm was analyzed in white blood cells using the Infinium MethylationEPIC v1.0 BeadChip kit. After filtering by a variance >0.36, we have worked with 5,261 CpG sites. We found four false discovery rate (FDR)-significant correlations between nutrients and CpGs sites: cg00167275 (GLUD1) correlated with alcohol, cg05218090 with folic acid, cg16682935 (PAPSS2) with selenium, and cg09821790 (SLC7A6) with fish food. One differentially methylated region (DMR) located at zinc finger protein gene 57 (ZFP57) was closely related to obesity and specific nutrients, food groups, and diet quality indices. The regression models of diet quality based on DNAm demonstrated that the most predictive values were when UPF and hPDI were considered. Also, UPF and hPDI were the best indices for predicting the main cardiometabolic risk factors. Our finding suggests that specific nutrients and diet quality indices may influence the degree of DNAm and putatively, the metabolic health in Spanish individuals.

Environmental DNA/RNA metabarcoding for noninvasive and comprehensive monitoring and assessment of marine fishes.

Marine fisheries resources are under increasing threat, necessitating the development of new effective monitoring and management strategies. Environmental DNA (eDNA) and RNA (eRNA) metabarcoding has emerged as a non-invasive and sensitive alternative method for monitoring fish biodiversity and fisheries resources and assessing the fisheries impact of anthropogenic activities. Here, we summarize crucial technical details about eDNA metabarcoding for marine fish monitoring and provide meta-analytical trends in primer selection and sample size, assessment standards, fish and fisheries databases, reference fish genomic databases, and other relevant metrics. The pressing need for better reference databases and standardization methods is discussed. We further highlight the potency of emerging eDNA metabarcoding studies for monitoring global fish diversity and revealed regional study hotspots in South China, Atlantic and Mediterranean Seas. The innovative advances in using eDNA/eRNA metabarcoding for fish diversity monitoring and assessment from the detection of rare or invasive species to branching applications in biomass estimation, population genetics, food web analysis, fish migration and feeding studies were reviewed. We also explore the potential of eRNA metabarcoding as an upcoming extension of eDNA metabarcoding in marine fish monitoring and assessment with improved functional relevance. We envision the integration of eDNA/eRNA metabarcoding-based fish monitoring methods with traditional monitoring approaches to significantly improve marine fish surveillance, ecological research, and conservation efforts.

Effect of Replacement of Fish Meal by Corn by Product Meal on Growth Performance For Nile Tilapia (Oreochromis Niloticus )

Effect of Replacement of Fish Meal by Corn by Product Meal on Growth Performance For Nile Tilapia (Oreochromis Niloticus )

The potential of hydrolyzed chicken feather meal as a partial replacement for fish meal and its effects on the growth and health status of African catfish (Clarias gariepinus) fingerlings

The potential of hydrolyzed chicken feather meal as a partial replacement for fish meal and its effects on the growth and health status of African catfish (Clarias gariepinus) fingerlings

Untargeted fast proteomics analysis using UPLC-Orbitrap HRMS for halal authentication of meat and meat products.

The authenticity of halal meat is a global issue because pork adulteration occurs. Certain religions, such as Islam and Judaism, prohibit the use of pork in food products. The purpose of this study was to evaluate the volume of trypsin with 10, 50 and 100 μL (20 μg/100 μL) and the digestion time from overnight to 30-120 min to establish a fast and straightforward procedure on proteomic analysis for halal authentication of meat and meat products. The method was applied to raw meat and processed pork products. The results show that 30 min digestion time and 50 μL of trypsin could detect specific peptides from pork. The proteins such as L-lactate dehydrogenase (D2SW96), haemoglobin subunit beta (F1RII7), carbonic anhydrase (A0A4XIUCS1), and myosin-1 (A0A481AX92) could be the alternative protein that contains specific peptide from pork that could be used as peptide biomarker in raw pork meat. Two peptides from haemoglobin subunit beta (F1RII7) protein heat stable peptide biomarkers were not previously reported. The method is proven for fast analysis, simple protein extraction, and rapid identification of specific pork peptides in raw meat and processed pork products. SIGNIFICANCE: The authenticity of halal meat is a global issue because pork adulteration occurs. Certain religions, such as Islam and Judaism, prohibit the use of pork in food products. Pork is frequently used as an adulterant in high-quality, high-priced meats such as beef, fish meat slices, lamb, or other meat to increase profits because pork is less expensive than the other meats. The purpose of this study was to evaluate the volume of trypsin and the digestion time to establish a fast and straightforward procedure on proteomic analysis for halal authentication of meat and meat products. The results show that 30 min digestion time and 50 μL of trypsin could detect specific peptides from pork. The proteins such as L-lactate dehydrogenase (D2SW96), haemoglobin subunit beta (F1RII7), carbonic anhydrase (A0A4XIUCS1), and myosin-1 (A0A481AX92) could be the alternative protein that contains specific peptide from pork that could be used as peptide biomarker in raw pork meat. To the best of our knowledge, this is the first report that studied on fast analysis, simple protein extraction, and rapid identification of specific pork peptides in raw meat and processed pork products.

Production of MANGANTA Tuna Shredded Fish

ABSTRACT Indonesia, as a maritime country, has abundant fishery resources, including in Lhokseumawe City, Aceh Province. Tuna and cob are the dominant fish species in Gampong Ujong Blang, Banda Sakti District, a key fishing center. However, excessive fish catches often exceed local demand, forcing fishermen to distribute them to nearby areas like Lhoksukon and Bireun. Those without delivery access struggle to sell their catch, leading to spoilage. Meanwhile, local fish processing industries lack facilities and knowledge to enhance fish value, resulting in tuna being consumed quickly before quality declines. To address this, processing tuna into shredded products presents a viable solution. "MANGANTA" shredded tuna offers a cheaper, lower-cholesterol alternative to beef floss. Enhanced with regional spices and fish meat separator technology, it has the potential to become an Acehnese food icon, creating business opportunities while addressing challenges faced by fishermen and processors. Keywords: Shredded tuna, MANGANTA, food technology, Acehnese spices, fish meat separator, innovation, fisheries industry.

Assessment of the nutritional and effluent properties of potential fish-meal-free diets for rainbow trout (Oncorhynchus mykiss W.) in Iran

Research is needed on alternative ingredients for aquafeeds due to rising demand and limited fish meal availability. This study evaluated fish-meal–free diets for rainbow trout in two phases. The first phase focused on assessing the growth performance and nutrient digestibility of six cold-pelleted diets. Aside from the control diet, the test diets contained poultry protein concentrate, blood meal, low-ash poultry by-product meal, 20–40% canola meal, and feather meal (Goldmehl®). Juvenile fish, averaging 5.3 g, were fed the diets for 56 days in a random-block design with four replicates per feed. Feces were collected using the settling method to evaluate nutritional digestibility and phosphorus availability. The feed from the primary phase, which resulted in the least-cost feed conversion ratio, was extruded and fed to fingerlings (14.6 g) in the second phase. This trial added to the first run in measuring digestibility parameters over a 28-day period. In parallel, extruded feed was given to grow-out fish, averaging 172.5 g, for 55 days in triplicate completely randomized tanks to evaluate growth performance and nutrient effluents. Throughout all the experimental runs, a casein-based laboratory pelleted feed was used for the respective controls. Feeding rainbow trout with 35% canola meal in both pelleted and extruded forms showed comparable results (P > 0.05) to the control in terms of growth performance and apparent digestibility for lipid (> 91%), crude protein (> 87%), and organic matter (> 78%). The extruded feed in this study represents an eco-friendly option for the growing aquafeed sector.

MERCURY FISH CONSUMPTION WITH NUTRITIONAL IMPLICATIONS IN INDONESIA: A LITERATURE REVIEW

ABSTRACTMercury poisoning is a global health issue that can be found in fish, and it is a source of concern in Indonesia, where fish consumption is on the rise due to small-scale gold mining and steam power plants. A literature review was conducted to see the distribution of mercury issues observed from the nutritional aspect in Indonesia. The literature review study analyzed previous research results using Google Scholar, Scopus, Pubmed, and Semantic Scholar databases. Keywords were mercury fish consumption, nutrition, Indonesia/konsumsi ikan bermerkuri, gizi, and Indonesia. Three experimental research articles were obtained, which were conducted in Indonesia. The study by Sofia et al. (2016) showed variations in mercury concentrations in seafood and human hair. Exposure to mercury was linked with noticeable symptoms and a decrease in body weight. Reza et al. (2016) found a correlation between the frequency of fish eating and the risk of mercury exposure. Research by Muflihatul Muniroh (2022) showed the exposure to mercury in pregnant women is due to the intake of seafood but had no significant effect on infant birth weight or length. Consumption of mercury-containing seafood affects weight loss and decreases body mass index (BMI). It is hoped that more research will be conducted on the nutritional implications of mercury fish consumption in Indonesia.Keywords: Mercury; fish consumption; nutritional status; Indonesia; heavy metal

The content and associated health risk assessment of toxic elements, micro-, and macrominerals in common carp, Wels catfish, and silver carp from the Danube River in Serbia.

Three fish species (common carp, Wels catfish, and silver carp) were collected from three locations along the Danube River in Serbia, and fish meat was analyzed for the content of toxic elements, micro- and macrominerals. Silver carp had the highest lead (Pb), arsenic (As), and cadmium (Cd) content, while Wels catfish had the highest level of mercury (Hg). Moreover, metal pollution index (MPI) ranged from 0.1096 to 0.275 and among the fish, the silver carp had the highest MPI (from 0.21 to 0.28), indicating that it could be reliable bioindicator of river pollution. Maximum determined levels of As (0.1968mg/kg of w.w.), Hg (0.175mg/kg of w.w.), and Pb (0.0315mg/kg of w.w.) did not exceed values prescribed by the European Commission Regulation, Codex Alimentarius Commission, Food and Agriculture Organization (FAO), and national regulations, but Cd in silver carp was at levels higher than prescribed (0.0808mg/kg of w.w.). Furthermore, our study's results showed that the target hazard quotient (THQ) of each analyzed element and hazard index (HI) were < 1, indicating that consumers would not be exposed to adverse health effects after consuming these fish species from the Danube River. Regarding target cancer risk (TR), for Pb this was below 10-6, which was regarded as negligible, while TRs for As and Cr were between 10-4 and 10-6, which was regarded as acceptable. Moreover, since the studied fish had low values of health risk indexes, it could be concluded that fish meat did not pose a significant risk to human health.

Nutritional Performance of Extracted Soybean, Full-Fat Soya and Maize Gluten Meal Compared to a Fishmeal-Based Reference Diet for Juvenile Tilapia (Oreochromis Mossambicus)

Modern diets for aquaculture are highly complex and utilize a broad range of ingredients, including animal and plant byproducts. This study focused on the rationale of obtaining primary nutritional responses of tilapia evaluating two major ingredients, namely soybean meal and maize gluten meals by replacing fishmeal at set levels of incorporation. A two-onth investigation evaluated selected plant protein sources compared to fish meal protein in scientifically formulated diets for fingerling tilapia (Oreochromis mossambicus). Six nutritionally balanced diets: one reference (control) diet (fish-meal based diet), three selected plant proteins (solvent extracted soybean, full-fat soybean, and maize gluten) were substituted for the LT (Low Temperature dried) fish-meal-based control diet protein at 50% respectively, and the remaining diets were replaced with 75% inclusion of solvent extracted soybean and maize gluten meals. Results showed that solvent extracted soybean meal, 50 (SESB50), Full fat soybean, 50% (FFSB50) and Maize gluten, 50% (MG50) fed tilapia did not appreciably differ in their growth performance (percent weight gain of 279.36, 249.23, and 194.13% respectively) with a final mean weight of 14.95g being significantly superior (&lt;0.05) for the fishmeal control (CO) group. Substitution of fish meal with solvent-extracted soybean and maize gluten at levels of 75% gave the poorest growth performance and Feed Efficiency (FE) (7.01g final weight, 51% FE). However, the MG50 diet also showed inferior feed utilisation performance. However, tilapia fed on a full-fat soybean diet (FFSB50) did not vary significantly from the control (CON) diet in terms of protein utilisation (ANPU) at 34.20% and 37.53% respectively. Whilst this preliminary study concluded that limitations on the use of the selected plant proteins in diets for tilapia are apparent, several approaches that could result in the future improvement of the nutritional value of soybean and maize gluten products for use in fish diets are also stated.

Understanding the reproductive ecology of Macrognathus aculeatus in wetland (Gajner beel) ecosystem: insights into eco-climatic influences in northwestern Bangladesh.

The lesser spiny eel, Macrognathus aculeatus (Bloch, 1786), holds substantial economic importance as a food fish in South Asia, due to its exceptional nutritional value. This study was conducted to investigate the reproductive ecology of M. aculeatus within the Gajner beel wetland ecosystem in northwestern Bangladesh, with a specific focus on size at sexual maturity, spawning season, and fecundity in relation to eco-climatic variables. A total of 649M. aculeatus female individuals were randomly collected from January to December 2018, with 440 mature selected for this study. The findings of this study revealed that the female's total length (TL) exhibited a range from 10.5 to 28.0cm. Multiple methods, including maximum length (Lmax), TL vs. gonadosomatic index (GSI), TL-standard length (SL) regression, and logistic model estimated the size at sexual maturity (Lm) at approximately 15.02cm, 14.0cm, 14.4cm, and 14.0cm, respectively. The spawning season was observed between May and August, with a peak in June-July. The Fulton's condition factor (KF) proved to be the most reliable indicator (p < 0.0001), with 50% and 90% of fish spawning at KF values of 0.38 and 0.42, respectively. Relative weight (WR) for females showed no significant deviation from 100 (p = 0.143), indicating a well-balanced M. aculeatus population. Fecundity varied from 600 to 7000 with TL and body weight (BW) that ranged from 10.5-28.0cm, to 3.33-87.05g, respectively. Fecundity was highly correlated with TL (p < 0.0001) and BW (p < 0.0001). The study also observed significant relationships between GSI and environmental factors, including temperature (p = 0.0016), dissolved oxygen (DO) (p < 0.0001), pH (p < 0.0001), alkalinity (p < 0.001), and climatic variable such as air temperature (p < 0.001) and rainfall (p < 0.001). The optimal range of DO, pH, and temperature for M. aculeatus spawning was found to be 5.82-6.10mg/l, 7.65-7.85, and 28.55-31.0°C, respectively. Additionally, our observation highlighted a robust correlation between GSI and rainfall. Moreover, data for 47years (1971-2018) indicated a gradual increase in average air temperature by 0.029°C per year and a decrease in annual rainfall by 2.96mm per year. These trends could potentially lead to a shift in the spawning season of M. aculeatus in the next 15-20years. This information holds significance for the conservation and sustainable management strategies of wild M. aculeatus stocks in the Gajner beel and its adjacent ecosystems, helping to address potential impacts of climate change.

Fish of Tuing-Tuing (Hydrundichthys Oxycephalus) as Abon Product

This study investigates the development of a new food product, specifically smoked tuing-tuing fish (Hirundichthys oxycephalus) abon, and assesses its acceptance among consumers. The objectives of the study purposes to find out the method for producing abon from smoked tuing-tuing fish meat, and to evaluate public preferences and acceptance regarding the final product’s characteristic, from the aspect texture, taste, aroma, and the colour of product. The research employs a quantitative methodology that combined with an experimental approach to create and refine the product. Data collection is comprehensive, involving primary sources such as direct observations and experiments, as well as secondary sources. Techniques used include detailed observations, experimental trials, structured questionnaires, and documentation throughout the experimental trial process to gather and analyze data. Eksperimental design as data analysis method is applied to interpret the results with data measurement using hedonic and sensory test. The result showed that smoked tuing-tuing fish can be effectively transformed into a desirable abon product. The final product of abon shows a distinctive brown color, noticeably smoked fish and spice aroma, a dry and non-greasy texture, and a flavorful of fish and savory taste. The hedonic and sensory tests indicate that the product meets high standards in all evaluated characteristics. Specifically, the product received positive feedback from respondent with high scores: 90% for texture, 93.2% for color, 92.6% for flavor, and 92.6% for taste. These scores place the smoked tuing-tuing fish abon in the “Very Like” category, reflecting strong consumer approval. So, it can be concluded that the research successfully demonstrates that smoked tuing-tuing fish can be utilized as a viable ingredient for producing fish abon. The high levels of acceptance and positive response from participants suggest that this product has significant potential in the market. The result underscore the viability of incorporating smoked tuing-tuing fish into new food products, highlighting the practical potential for this innovative approach. This research provides a solid foundation for further development and commercialization efforts, preparing for the introduction of a unique and marketable product.