Fish Meal Research Articles

A two-year plant-based diet alters the fatty acid profile and enzymatic and non-enzymatic lipid metabolites, in the eggs and fry of female rainbow trout

To promote sustainable aquaculture, plant-based ingredients are increasingly being used to replace fish meal (FM) and fish oil (FO) in diets, affecting critical fatty acid (FA) profiles in broodstock diets. These profiles are essential for reproduction and offspring survival. The absence of traditional fish-derived nutrients results in an altered FA composition, particularly a reduction in omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs). This change is detrimental to trout reproduction over the long term. Current research gaps, especially regarding FA profiles and related metabolites, limit our understanding of the reproductive consequences of omega-3 deficient plant-based diets. To fill this knowledge gap, a two-year trial was conducted to compare the reproductive effects (spawning performances, egg quality, embryo development) of two diets on rainbow trout females: a plant-based diet containing linseed (10.8 %), palm (5 %), and sunflower oils (2.7 %), and a commercial diet with high FM (27 %) and FO (12.1 %) content. Both diets were similar in terms of protein (44 %), lipids (23.4 %), and energy (25 kJ/g). The study spanned from initial feeding to first reproduction, and fatty acid profiles and metabolites (selected enzymatic and non enzyamatic metabolites from FA) were examined in the broodstock diet, female muscle tissue, eggs, and fry. Trout fed a plant-based diet showed reduced reproductive traits such as lower weight and fecundity, but egg and embryo quality remained high. Survival and hatching rates were similar to those on commercial diets. The study revealed for the first time the critical role of maternal diet in the generation of lipid metabolites in the offspring, particularly DHA (F4-neuroprostane, maresin, 14-HDoHE) and AA (F2-isoprostane, prostaglandin E and F2, 8–12- 15-HETEs) oxylipins, highlightingthe complex dietary influences on fish reproduction. This work underlines that a plant-based diet significantly affects the the reproductive performance of broodstock trout by altering fatty acid profiles and metabolite levels and highlights the delicate balance between dietary components, oxylipins, and reproductive functions in fish, suggesting the need for more comprehensive studies of their interrelated effects.

Zootechnical Performance, Protease Activity and Proximate Composition of Nile Tilapia Fed Diets Containing Fish Silage Produced from Fish Waste

The present study was carried out to evaluate the impact of fish silage (FS) on the growth performances, protease enzyme activity and muscle compositions of Nile tilapia. In this regard, FS was produced from the waste parts of carp, pangus and tilapia and five iso-nitrogenous (containing 35% crude protein) diets were formulated in which fishmeal (FM) was used as the primary protein source in the control diet (0% FS, T1). The remaining four diets were formulated by replacing 25% (T2), 50% (T3), 75% (T4), and 100% (T5) FM protein with the FS. These diets were fed to tilapia at 8-6% of their body weight rearing them in glass tanks at the density of 15 fish/tank in triplicates. After fifty-days feeding trial, survival (%) of fish remained unaffected among the dietary treatments. Tilapia fed with 75% FS based diet showed improved growth and lower FCR, whereas those fed a diet with 100% FS exhibited lower growth rates. Notably, protease enzyme activity (mg/ml/min) increased with higher levels of FS inclusion. Increased crude protein content was observed in the fish fed the 75% FS diet. These findings underscore the potential of including FS up to 75% to enhance the growth performance of Nile tilapia.

STUDY ON EFFECT OF CHENOPODIUM QUINOA ON GROWTH PERFORMANCE, CARCASS COMPOSITION AND ANTIOXIDANT ACTIVITY OF OREOCHROMIS NILOTICUS AND CYPRINUS CARPIO

Plant-based protein sources are suitable and profitable for aquaculture. Chenopodium quinoa is one of the pseudo-cereal plants and promising source of protein. A 60-day feeding experiment was designed to check the impacts of C. quinoa seed meal (CQSM) on growth indices, carcass composition and antioxidant activity of Oreochromis niloticus and Cyprinus carpio. Six test diets as I, II, III, IV, V and VI were formed by using CQSM as replacement of fishmeal (FM) at 0%, 10%, 20%, 30%, 40% and 50%, respectively. Triplicate tanks having 15 juveniles in each were used and juveniles were fed at a diet equivalent to 5% of their live wet weight. Digestibility was measured with the help of feces. In O. niloticus and C. carpio, maximum results for weight gain (13.65g), (14.12g), feed conversion ratio (FCR) (0.98), (0.92), weight gain% (168.80), (199.15), and specific growth rate (SGR) (1.63), (1.21), respectively, were seen at level-III (20%) replacement of FM with C. quinoa seed meal based diet. For nutrient digestibility, best results in O. niloticus and C. carpio were also noticed at 20% replacement of FM with CQSM as crude protein (CP) (68.59), (66.30), crude fat (CF) (65.82) (65.65) and gross energy (GE) (72.36), (65.60), respectively. The antioxidant activity was maximum: 6.56 for O. niloticus and 7.13 for C. carpio at 20% replacement of FM. The findings indicated that the substitution of FM with CQSM up to 20% has a positive effect on fish growth, carcass composition, antioxidant activity and nutrient digestibility. Keywords: Quinoa seed meal, Pseudocereal plants, Fishmeal, Growth performance, Antioxidant activity.

Alginate-based active and intelligent packaging: Preparation, properties, and applications

Alginate-based packaging materials have emerged as promising alternatives to conventional petroleum-based plastics due to their biodegradability, renewability, and versatile functionalities. This review provides a comprehensive analysis of the recent advances in the development and application of alginate-based films and coatings for food packaging. The composition and fabrication methods of alginate-based packaging materials are discussed, highlighting the incorporation of various functional compounds to enhance their physicochemical properties. The mechanisms of action and the factors influencing the release and migration of active compounds from the alginate matrix are explored. The application of alginate-based packaging materials for the preservation of various food products, including meat, fish, dairy, fruits, and vegetables, is reviewed, demonstrating their effectiveness in extending shelf-life and maintaining quality. The development of alginate-based pH-sensitive indicators for intelligent food packaging is also discussed, focusing on the colorimetric response of natural pigments to spoilage-related pH changes. Furthermore, the review highlights the challenges and future perspectives of alginate-based packaging materials, emphasizing the need for novel strategies to improve their performance, sustainability, and industrial adoption.

Genomic portraits of methicillin-resistant staphylococci (MRS) from food fish unveiled the genes associated with staphylococcal food poisoning (SFP), virulence and antimicrobial resistance

BackgroundCharacteristics of non-clinical strains of methicillin-resistant Staphylococcus aureus (MRSA) especially from fishery environment are poorly understood. This research, in addition to comprehensive characterisation, sought to delineate the genetic relatedness between the MRSA strains originating from clinical as well as non-clinical settings. Out of 39 methicillin-resistant staphylococcal isolates from 197 fish samples, 6 (Three each of methicillin-resistant S. haemolyticus (MRSH) and MRSA) with distinct resistance profiles were selected for whole-genome sequencing. Using respective bioinformatics tools, MRSA genomes were comprehensively characterized for resistome, virulomes, molecular epidemiology and phylogenetic analysis. Simultaneously, MRSH genomes were specifically examined to characterize antimicrobial resistance genes (ARGs), owing to the fact that MRSH is often recognized as a reservoir for resistance determinants.ResultsThree MRSA clones identified in this study include ST672-IVd/t13599 (sequence type-SCCmec type/spa type), ST88-V/t2526, and ST672-IVa/t1309. Though, the isolates were phenotypically vancomycin-sensitive, five of the six genomes carried vancomycin resistance genes including the VanT (VanG cluster) or VanY (VanM cluster). Among the three MRSA, only one harbored the gene encoding Panton-Valentine Leukocidin (PVL) toxin, while staphylococcal enterotoxin (SEs) genes such as sea and seb, associated with staphylococcal food poisoning were identified in two other MRSA. Genomes of MRSH carried a composite of type V staphylococcal cassette chromosome mec (SCCmec) elements (5C2 & 5). This finding may be explained by the inversion and recombination events that may facilitate the integration of type V elements to the SCC elements of S. aureus with a methicillin-susceptible phenotype. Phylogenetically, MRSA from a non-clinical setting displayed a considerable relatedness to that from clinical settings.ConclusionThis study highlights the genetic diversity and resistance profiles of MRSA and MRSH, with non-clinical MRSA showing notable relatedness to clinical strains. Future research should explore resistance gene transfer mechanisms and environmental reservoirs to better manage MRSA spread.

Emergence of multidrug resistant mobile colistin resistance (mcr) carrying Aeromonas spp. isolated from retail foods in Mymensingh district, Bangladesh

The emergence of plasmid-mediated mobile colistin resistance (mar) in bacteria under Enterobacteriaceae, and aeromonads isolated from foods has been reported in many parts of the world. So far, we know there is no report of mcr carrying Aeromonas spp. Isolated from retail foods in Bangladesh. Therefore, this study was carried out to determine the prevalence of mcr carrying Aeromonas spp. isolated from retail foods (meat, milk, and fish) in Mymensingh district and their characterization for antimicrobial resistance patterns. The prevalence of mcr-1 gene carrying Aeromonas spp. was 30 % (15/50) in chickens, 23 % (8/35) in fish, and 10 % (2/20) in milk. No other tested mcr gene variants (mcr-2 to 4) were detected. The minimum inhibitory concentration (MIC) for colistin was determined to be 80% (12/15) and 75% (6/8) of the mcr-1 gene carrying Aeromonas spp. isolated from chicken and fish, respectively, had an MIC of 8-16 µg/ml whereas 100% (2/2) of the isolate from milk showed a MIC of 4–8 µg/ml. Most of the mcr-1 gene-carrying isolates from chicken meats, fish, and milk were resistant to oxytetracycline, and ampicillin (80%–100%). Apart from multidrug resistant (MDR), extensive MDR was detected in mcr-1 gene-carrying Aeromonas spp., irrespective of the sample’s origin. Overall, these data suggested that the mcr-1 gene-carrying Aeromonas spp. in retail foods could be a potential reservoir for antimicrobial resistance determinants. To the best of our knowledge, this is the first report of the mcr gene carrying Aeromonas spp. isolated from retail foods such as chicken meat, fish, and milk in Bangladesh. Res. Agric. Livest. Fish. Vol. 11, No. 2, August 2024: 115-124

Impact of Various Dietary Protein Sources on Growth Performance of Nile Tilapia (Oreochromis niloticus) Fingerlings and on Water Quality

Aquaculture industry provides proteins and unsaturated fatty acids worldwide. Fresh water aquaculture is considered as the most prominent type of aquaculture in the world. Nile tilapia aquaculture is favored because it can adopt to wide range of environments and can tolerate various abiotic stresses. However, the success and profitability of aquaculture is significantly affected by type of feeds used in aquaculture system. An experiment was conducted to assess this important aspect of aquaculture. Nile tilapia fingerlings were fed on three different protein sources to assess the effects of these experimental diets on growth of fingerlings and on water quality. Three protein sources were freshwater shrimp meal (FSM), black soldier fly larvae (BSF) and soybean meal (SBM). Fingerlings were divided into groups based on their respective experimental diets and were arranged according to CRD with three replicates. Each replicate contained 30 fingerlings. Data was recorded for growth attributes of fingerlings and for water quality attributes. Analysis of data shows that BSF caused 32% increase in final weight of fingerlings followed by FSM, which caused 24% increase as compared to controlled. Net weight gain was also significantly enhanced by experimental diets. BSF caused 88% increase in weight gain as compared to controlled. BSF also increased 43% survival rate of Nile tilapia fingerlings as compared to fingerlings fed with controlled diet. Water quality was not much affected by all diets. Water quality parameters like DO, pH, temperature, ammonia and phosphorus all were in optimum range for tilapia culture. However, BSF provided 136% more phosphorus as compared to controlled. This study reveals the beneficial effects of BSF larvae protein source for Nile tilapia culture. So, from these findings, it can be suggested to partially replace fish meal with BSF larvae meal.

Impact of Various Dietary Protein Sources on Growth Performance of Nile Tilapia (Oreochromis niloticus) Fingerlings and on Water Quality

Aquaculture industry provides proteins and unsaturated fatty acids worldwide. Fresh water aquaculture is considered as the most prominent type of aquaculture in the world. Nile tilapia aquaculture is favored because it can adopt to wide range of environments and can tolerate various abiotic stresses. However, the success and profitability of aquaculture is significantly affected by type of feeds used in aquaculture system. An experiment was conducted to assess this important aspect of aquaculture. Nile tilapia fingerlings were fed on three different protein sources to assess the effects of these experimental diets on growth of fingerlings and on water quality. Three protein sources were freshwater shrimp meal (FSM), black soldier fly larvae (BSF) and soybean meal (SBM). Fingerlings were divided into groups based on their respective experimental diets and were arranged according to CRD with three replicates. Each replicate contained 30 fingerlings. Data was recorded for growth attributes of fingerlings and for water quality attributes. Analysis of data shows that BSF caused 32% increase in final weight of fingerlings followed by FSM, which caused 24% increase as compared to controlled. Net weight gain was also significantly enhanced by experimental diets. BSF caused 88% increase in weight gain as compared to controlled. BSF also increased 43% survival rate of Nile tilapia fingerlings as compared to fingerlings fed with controlled diet. Water quality was not much affected by all diets. Water quality parameters like DO, pH, temperature, ammonia and phosphorus all were in optimum range for tilapia culture. However, BSF provided 136% more phosphorus as compared to controlled. This study reveals the beneficial effects of BSF larvae protein source for Nile tilapia culture. So, from these findings, it can be suggested to partially replace fish meal with BSF larvae meal.

Effects of Chemically and Green Synthesized Zinc Oxide Nanoparticles on Shelf Life and Sensory Quality of Minced Fish (Pangasius hypophthalmus).

The purpose of this study was to investigate the effect of chemically and green synthesized zinc oxide nanoparticles (ZnO-NPs) on the shelf life and sensory quality of fish meat. In this study, ZnO-NPs were synthesized by employing the colloidal chemistry (CZnO-NPs) and green synthesis (GZnO-NPs) methods, and they were also characterized to assess their morphology. The synthesized ZnO-NPs, ZnO, and zinc acetate (ZnA) were used for the preservation and fortification of fish (Pangasius hypophthalmus) meat at 20 mg/kg of Zn. In a six-day storage study at 4 °C, the fish samples were evaluated for their sensory attributes (color and odor), physicochemical quality (pH and total volatile base nitrogen), oxidative changes (thiobarbituric acid-reactive substances and peroxide value), and microbial loads at 0, 3, and 6 days of storage. The fortification of raw fish with the synthesized CZnO-NPs produced better sensory attributes (color and odor) and maintained a pH non-conducive to microbial growth throughout the entire storage period compared with the control, ZnO, and ZnA-fortified samples. The GZnO-NPs largely did not provide any added advantage over CZnO-NPs but sometimes responded better than the control, ZnO, and ZnA samples. Oxidative status and total volatile base nitrogen were lower for CZnO-NPs in refrigerated fish compared with the other treatments. The ZnO-NP-fortified fish had the lowest counts of total viable bacteria, coliforms, Staphylococcus spp., and Vibrio spp. Hence, the fortification of fish with synthesized CZnO-NPs is promising as a food additive to reduce microbial spoilage and lipid peroxidation of fish in storage.

The Role of Cyano-HAB (Cyanobacteria Harmful Algal Blooms) in the One Health Approach to Global Health

Harmful algal bloom events occur in salt, brackish, and fresh water. In bodies of water such as oceans and estuaries, diatoms or dinoflagellates form “tides” that produce toxins associated with seafood poisoning, including paralytic shellfish poisoning, or respiratory distress from inhalation of aerosolized toxins. Cyanobacteria predominantly bloom in fresh water; they can produce microcystins; cylindrospermopsin; and other toxins that humans or animals might be exposed to through water contact, inhalation, or ingestion. Animals that become ill or die can be sentinels for harmful algal bloom events. In a One Health approach, information about harmful algal bloom exposures and health effects support efforts to detect these events and mitigate and prevent associated illnesses. Human, animal, and environmental health partners can work together to document the occurrence and impacts of harmful algal bloom events and characterize associated illnesses.

Nutrient Status of Some Food Fishes with Respect to Their Proximate Composition: A Review

The nutritional awareness is a vital issue in most of the developing countries. Consumption of imbalance nutrients is globally responsible for the malnutrition, a curse for the people who belongs to below poverty line. Fish is a vital source of protein and many other essential nutrients for the human health. More than one billion of people around the world include fish food in their regular diet. Many of the developing countries like India are resided by poor villagers who gladly consume the small fish species which are of low cost and easily available in the water lands. The nutrient status the small food fishes are of greater interest to the researchers in the field of biochemistry in terms of their socio-economic impact and sustainable human food chain. Advanced researches on the biochemical constituents of different fishes are signified and essential to the human health as well as medicinal practitioners to formulate newer medicines for the prevention of many life risk diseases of the community. This review article is an attempt to review the current scientific literatures on the nutrient status with respect to their proximate composition of different fish species across the globe. The significance of such study on Food-to-food fortification (FtFF) on the basis of proximate composition of fish along with challenges and future perspectives are also highlighted.

Effect of two full-fat insect meals, yellow mealworm and black soldier fly larva, on growth performance of juvenile yellowtail

Abstract Given the expanding demand for fish meal (FM) worldwide, insect meal has become a promising alternative to FM for sustainable aquaculture. Yellowtail (Seriola quinqueradiata), the predominant farmed fish in Japan, is a carnivorous marine species that requires a substantial quantity of FM in its diet. Two feeding trials were conducted with the aim of assessing the applicability of two full-fat insect meals, yellow mealworm (Tenebrio molitor) meal (TM) and black soldier fly (Hermetia illucens) larvae meal (HI), as FM substitutes in for juvenile yellowtail. In the first trial, replacing 24.3% of FM with TM resulted in a final fish weight of 137.4 ± 40.1 g (mean ± SD as also indicated for subsequent values), comparable to the control group with a weight of 139.5 ± 44.0 g, while maintaining an equivalent level of n-3 fatty acid content across all diets used in the trial. The body weight of fish fed a diet containing HI, at 121.2 ± 31.0 g, was significantly lower than the control group, whereas the difference between fish fed a diet containing TM was not statistically significant. According to the growth analysis, dietary inclusion of TM was more suitable than that of HI, prompting a second trial to evaluate the maximum limit of FM substitution with TM without adjusting fatty acid profiles across diets. In the subsequent trial, fish growth exhibited a clear decrease trend with the inclusion rate of TM. These findings suggest that, while the substitution of FM with HI and TM has been shown to be feasible under equivalent fatty acid profiles in diets, the imbalanced fatty acid profile resulting from the inclusion of full-fat insects could be attributed to a deficiency in n-3 fatty acids, leading to the observed growth retardation in juvenile yellowtail.

The effect of blood meal to induce aquaculture performance of striped catfish (Pangasionodon hypophthalmus Sauvage, 1878)

Abstract The high price of fish meal as feed is the main problem in cultivating striped catfish. The use of blood meal, waste from slaughterhouses, can be an alternative to improve aquaculture performance while reducing feed costs. This research aimed to determine the effect of using blood meal as a source of feed protein on the growth performance of striped catfish. The research design used was a Completely Randomized Design (CRD) consisting of five treatments and three replications. The treatments used were A (blood meal 0%, fish meal 100%) as control, B (blood meal 25%, fish meal 75%), C (blood meal 50%, fish meal 50%), D (blood meal 75%, fish meal 25%), and E (blood meal 100%, fish meal 0%). The results showed that the average body weight and specific growth in treatments B (8.25 ± 0.63b g, 3.51 ± 0.13b %/day) and C (8.26 ± 0.73b g, 3.52 ± 0.14b %/day) had the same performance as the control. It is concluded that blood meal can be substituted and combined with fish flour with a maximum composition of 50% to improve the performance of striped catfish aquaculture. Further research to increase the nutrition of blood meal must be conducted to improve the aquaculture performance of striped catfish.

Natural radioactivity and heavy metal contamination in edible fish, shellfish and mollusks at the Bay of Bengal, Kuakata, Bangladesh

In this study, gamma activity concentrations, gross alpha and gross beta activity of natural radionuclides, and heavy metal concentrations were measured in eleven edible marine fish, four shellfish, two mollusks, and a common seaweed sample collected from a local sea fish market and sea beach area of the northern part of the Bay of Bengal, Kuakata, Bangladesh. Using HPGe gamma spectrometry, the activity concentrations of 238U, 232Th, and 40K were measured and found to be 19.7 ± 1.5 Bq/kg, 12.2 ± 0.9 Bq/kg, and 188 ± 15 Bq/kg, respectively, with the 232Th concentration surpassing that of 238U. The ZnS scintillation detector was used to assess the gross alpha and gross beta activity. The average gross alpha activity and gross beta activity were found to be 9.4 ± 1.4 Bq/kg and 26 ± 4 Bq/kg, respectively, with the latter attributed to beta emitting radionuclides's abundance. The activity concentrations of 238U, 232Th, and 40K in the analyzed samples varied in the order of Shellfish > Seaweed > Fish > Mollusks, Seaweed > Shellfish > Mollusks > Fish, and Seaweed > Shellfish > Fish > Mollusks. The annual effective dose due to consumption of analyzed seafood was found to be within the world limit of 2400 μSv/y recommended by UNSCEAR. The main contributor to the annual effective dose was 238U. The excess lifetime cancer risk (ELCR) results were below the permissible threshold of 10−3 for radiological risks. Furthermore, average concentrations of Zn and Mn were higher than WHO/FAO recommended values, and carcinogenic Pb, Cd, Cr, and Hg concentrations were below detection limits, according to heavy metal analysis performed by AAS. The average concentration of heavy metals in all of the seafood samples under investigation was in the order of Zn > Fe > Mn. The calculated hazard index (HI), target hazard quotient (THQ), and estimated daily intake (EDI) were compared to the permissible safety limits.

Alien Species of the Lower Volga and the Caspian Sea: Fish Fauna and Food Resources (Intentional Introduction)

Alien Species of the Lower Volga and the Caspian Sea: Fish Fauna and Food Resources (Intentional Introduction)

Supplementation of fish meal with moringa oleifera seed meal (MOSM) and its effect on growth performance and survival in ROHU, Labeo rohita (Hamilton, 1822) fry

Supplementation of fish meal with moringa oleifera seed meal (MOSM) and its effect on growth performance and survival in ROHU, Labeo rohita (Hamilton, 1822) fry

Estimation of life history parameters of the Gangetic leaffish, Nandus nandus from southern coastal waters of Bangladesh: Implications for sustainable management

The Nandus nandus (Hamilton, 1822) is a highly prized food fish that possesses significant nutritional and commercial worth. Bangladesh, India, Pakistan, Malaysia, Myanmar, Thailand and Viet Nam are the countries where it is endemic. The IUCN Bangladesh has classified this species as near endangered due to its current progressive decline. Hence, immediate actions are necessary to efficiently manage the fishery in this country. To address this issue, a comprehensive understanding of its life history parameters is required. This study aimed to examine the growth characteristics, recruitment length, sexual maturity, mortality, exploitation rate, and maximum sustainable production of N. nandus in Bangladesh's southern coastal waters. Samples were taken every month from January through December of 2021. Our study indicates that N. nandus grows in an isometric manner. The estimated asymptomatic length of this species is 18.0 cm in total length (TL), growing at a rate of 1.30 year−1. The growth performance index of this species was determined to be 2.62, and the projected lifespan was calculated to be 2.31 years. The initial length at recruitment was measured to be 9.5 cm TL, whie the size at first sexual maturity was recorded to be 9.4 cm TL. With the contributions of the natural mortality rate (2.26 year−1) and the fishing mortality rate (1.86 year−1) the total mortality rate was found to be 4.12 year−1. The exploitation rate, determined to be 0.45, surpasses the upper limit of sustainable yield criteria set at 0.37. Therefore, it is imperative to implement strategies to avoid excessive fishing and guarantee the long-term control of N. nandus populations.

Effects of Formulated Pellet Feed or Live Fish Food on the Intestinal and Aquaculture Water Microbial Communities in Goldfish, Carassius auratus

This study investigates the impact of different diets on fish growth and bacterial community structure present in the intestine of goldfish (Carassius auratus) and their aquaculture water under recirculating water conditions. We assumed that different types of diet would form different intestinal microbiota that may affect host growth. Using Illumina MiSeq high-throughput sequencing, we analyzed bacterial communities in goldfish fed with formulated pellet feed, Tubifex worms (Limnodrilus hoffmeisteri), and an alternating diet of both. Over a 14-day feeding trial, no significant differences in juvenile goldfish growth were observed between groups. After 7 days, diet changes significantly influenced the abundance and diversity of intestinal bacteria, with the alternating diet notably enhancing bacterial diversity in both the intestines and water. However, these differences in bacterial diversity decreased by day 14. The results indicate that diet type affects microbial community diversity in the intestines and water of goldfish, and that goldfish intestines maintain a stable core bacterial community structure. This highlights the potential for optimizing diet types to enhance microbial health and stability in aquaculture systems and, in addition, provides an important scientific basis for alternative diets in goldfish aquaculture in the industry.

Freshwater snail flesh (Pomacea paludosa) incubated with bromelain enzyme levels in feed on the carcass quality of Alabio male ducks (Anas plathyrhyncos Borneo)

This study aimed to determine Freshwater snail flesh (Pomacea paludosa) incubated with bromelain enzyme levels in feed on the carcass quality of alabio male ducks. The treatment as ; P0 basal diet + 100% fish meal, P1 basal diet + 75% fish meal + 25% freswater snail flesh incubated bromelain enzym, P2 basal diet + 50% fish meal + 50% freswater snail flesh incubated bromelain enzym, P3 : basal diet + 25 % fish meal + 75% freswater snail flesh incubated bromelain enzym, P4 : basal diet + 100% freswater snail flesh . In each treatment, two male Alabio ducks were taken randomly and then slaughtered. The crude protein, crude fat, moisture, pH, and texture, by taking as many samples as 20 g of sample then mashed for 2 minutes and added 40 ml aquadest. pH measurement is done with pH meter, which was previously calibrated with buffer solution of pH 7.0 and 4.0. Meat tenderness is measured by using the shear warner bratzler tool Instron, , protein,fat and moiture using proximate analysis The result showed that level freshwater snail flesh incubated with bromelain enzym in feed up to 7.5-10% on Alabio male duck diets improved crude protein meat (21.51±0.19 to 23.90±0.40) but decreased meat moisture ( 69.46±0.79 to 62.79±0.27) and decreased crude fat meat (9.55±0.44 to 4.18±0.53). Meanwhile, the tenderness of the meat increased from 3.55% on the control feed to 26.77% on the feed using 7.5-10%.

Effects of Different Roasting Methods on the Quality of Roasted Large Yellow Croaker (Larimichthys crocea).

This study investigated the effects of different roasting methods (45% light wave and 55% microwave roasting, 70% light wave and 30% microwave roasting, 100% light wave roasting, far-infrared roasting, and oven roasting) on the quality of roasted large yellow croaker. The quality was evaluated using sensory evaluation, texture characteristics, color differences, moisture content, and volatile flavor substances. In this context, different roasting methods can affect the color, taste, and flavor of large yellow croaker fish, significantly improving the overall acceptance of roasted fish. The results showed that after 45% light wave and 55% microwave roasting, the elasticity of fish meat was maintained, the hardness of fish meat was reduced, the moisture content and distribution were changed, and the taste was the best. Far-infrared roasting and 45% light wave and 55% microwave roasting had a significant effect on the color of large yellow croaker samples and improved the sensory evaluation score. Forty-six volatile compounds were detected using gas chromatography-mass spectrometry. After roasting, the oxidation and Maillard reactions of lipids and proteins were increased, with the 45% light wave and 55% microwave roasting giving the highest variety of volatile flavor substance products.