This study aimed to evaluate growth performance, amino acid and fatty acid composition of fillets, and blood biochemistry of hybrid catfish (Heteroclarias) cultured on Black Soldier Fly (BSF), Hermetia illucens larval-based diets. The experiment was conducted in a recirculating system, circular poly tanks (350 L), in a completely randomized design. Four isonitrogenous (400 g kg-1 crude protein) and isolipidic (140 g kg-1 crude fat) diets were formulated in which fishmeal (400 g kg-1) was replaced at 0%, 25%, 50%, and 75% with defatted BSF larval meal and fish oil was completely replaced with corn oil in the test diets. 180 hybrid African catfish (12 weeks post-hatching) with an initial body weight of 200 ± 25 g were randomly distributed in the 12 experimental tanks (15 fish per tank, 45 fish per treatment) and were hand-fed at 3% body weight for 8 weeks. The findings showed that replacing 50% of fishmeal with BSF meal resulted in the highest growth performance (final weight, weight gain, specific growth rate [SGR], thermal growth coefficient [TGC]). However, at 75% level, growth performance and nutrient utilization (FCR, PER) significantly decline (p < 0.05). The dietary modification had no significant impact (p > 0.05) on organosomatic indices, proximate composition, amino acid profile, deposition, or retention of arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and sum n-3 polyunsaturated fatty acids (PUFA) in fish fillets. There were no significant differences in the hematological parameters (p > 0.05) across all treatments. Except for a reduction in globulin and cholesterol levels, all the plasma metabolites, including alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, remained stable (p > 0.05). Overall, the findings of this study suggest that BSF larval meal may partially replace dietary fishmeal up to 50% (200 g kg-1), and corn oil may completely replace fish oil in a practical diet for hybrid African catfish without exerting adverse impacts on growth, feed conversion efficiency, fillet quality, health status, and physiological well-being.

Objective. This study aimed to determine the effect of feeding mealworms with walnut and flaxseed oils on productive performance and fat composition. Materials and Methods. Mealworms were reared on diets supplemented with flaxseed and walnut oils. The oils were mixed with ground whole wheat grain and included at three levels: 0.5%, 1%, and 1.5%. The weight and length of the worms were recorded weekly. At the end of the experiment, worms were analyzed for nutritional content and fatty acid composition. Results. Significant differences were observed in relative growth rate, daily growth rate, and absolute daily gain. Significant differences were also found in the composition of saturated, monounsaturated, and polyunsaturated fatty acids. Conclusions. The inclusion of omega-3-rich oils did not affect survival rates. However, it reduced growth performance across all inclusion levels, increased fat content, and did not enhance omega-3 deposition in mealworm tissue.

The aim of this study was to examine the impact of the probiotics Saccharomyces cerevisiae (SC) and Pediococcus acidilactici (PA), as well as the prebiotic yeast cell wall extract (Cyberlindnera jadinii and S. cerevisiae) (YP), on the growth parameters, intestinal histomorphology, liver and gills normality, and gut microbiome of common carp (Cyprinus carpio L.). These feed supplements were subjected to a 60-day experimental period, during which 120 fish (26.4 ± 5.2 g) were distributed into four groups, with each group comprising 30 fish. The feed supplements were administered at a rate of 1 g/kg of body weight. Before the trial, the fish were acclimatized for two weeks, then injected with Passive Integrated Transponder (PIT) tags. The results showed that none of the feed supplements exhibited a significant effect (p > 0.05) on growth indices. In contrast, the villi length, villi width, muscular thickness, and crypt depth in the anterior, mid, and posterior intestine of the SC group exhibited significant (p < 0.05) improvements compared to the other groups. No alteration or abnormal growth were noticed in the gills and livers. The most dominant microbe genera in all groups, with abundances greater than 60% of the total, were Cetobacterium and Aeromonas. However, Polynucleobacter, Nordella, Mycoplasma, Romboutsia, and Staphylococcus species were present at lower abundances. The presence of Actinobacteria has been observed only in the intestine of fish that have been fed a diet supplemented with PA. It can be concluded that the tested probiotics and the yeast cell wall prebiotic have the potential to produce a remarkable improvement in intestinal morphology and a considerable change in the gut microbiome without notable effect on growth, livers, or gills of common carp.

Az emberiség állati-fehérje szükségletének kielégítésére az akvakultúrás termelés adhat megoldást. A Clarias gariepinus és a Heterobranchus longifilis harcsafajok keresztezésével előállított Heteroclarias jó növekedési eréllyel, magas technológiai és környezeti tűrőképességgel rendelkező fajhibrid. A hibridben rejlő genetikai potenciál kihasználásának érdekében intenzív takarmányozást igényel, így nevelése nagy környezeti terhelést jelenthet. Kísérletünk célja ezért az volt, hogy megvizsgáljuk, milyen hatással van az apró békalencse (Lemna minor), mint biológiai szűrő integrálása egy intenzív haltermelő rendszer vízminőségi paramétereire. Kísérletünkben két turnusban állítottunk elő Heteroclarias ivadékot félüzemi körülmények között 15 köbméteres víztérfogatú recirkulációs rendszerben (RAS). Az első turnus volt a kontroll (K), a második turnusban pedig a rendszerbe biológiai szűrőként integráltuk a Lemna minor békalencse fajt (BL). A békalencse biofilterként történő alkalmazása nem befolyásolta a halak termelési paramétereit. A vízminőségi paraméterek vizsgálata ugyanakkor azt mutatta, hogy a békalencse alkalmazása csökkentette a rendszervíz átlagos ammónia ((K) 1,26 mg/l és (BL) 0,29 mg/l) és nitrit ((K) 1,81 mg/l; (BL) 0,17 mg/l) koncentrációját a kontroll csoporthoz képest. Ennek eredményeként jelentősen csökkent a megfelelő vízminőség fenntartása érdekében végrehajtott vízcserék száma, amely nemcsak gazdasági előnyt jelent, de fenntarthatóbbá is teszi az ivadéknevelés folyamatát is.

In aquaculture systems, a high proportion of nutrients end up in the water as a by-product of metabolic processes. These must be neutralized through filtration, but to increase efficiency, the integration of some aquatic plants is advisable. Through the nutrient uptake capacity of these plants, the environmental impact of aquaculture systems can be decreased, so they become more sustainable. In this experiment, common duckweed (Lemna minor) was used under different harvesting protocols (control, and 25% and 50% of surface area harvested) to examine the nutrient uptake capacity of the plant and the effects on fish (common carp—Cyprinus carpio) production parameters. It can be concluded that the treatments used did not have a significant effect on fish production parameters. However regular duckweed harvesting had a positive effect on the plant’s biomass production and daily growth rate. By the end of the experimental period, the harvested groups had accumulated more biomass than the control group, though there was no difference between the 25% and 50% harvest rates. In our experiment, the control group achieved a yield of 17.9 t/ha/year, while the regularly harvested (25% and 50%) treatments achieved yields of 23.4–24 t/ha/year (based on extrapolated data). Regular harvesting of duckweed resulted in lower ammonia levels, as the free water surface available to the plants after harvesting allowed for more intensive growth, enabling them to absorb more organic matter. The dynamics of nitrite, nitrate and orthophosphate concentrations are primarily determined by the internal biochemical processes of the system and temporal development, while treatments such as duckweed harvesting had no direct effect on these parameters.

(1) Background: In vitro experiments in fish have been developed to search for dietary substitutes of fish meal in aquafeeds by measuring the digestibility of various feedstuffs by simply simulating the conditions of the stomach or portions of the digestive tract. In vitro digestion studies involving mainly commercial fish species have been conducted to determine the digestibility of conventional and alternative ingredients in fish diets using diverse digestion models. However, there remains a significant knowledge gap, particularly regarding the enzyme functionality, digestion mechanisms in many fish species, and the factors influencing enzymatic activity. This review article is focused on the importance of the use of different enzyme sources in the in vitro digestion model to predict protein hydrolysis.;(2) Methods: For this review, a comprehensive analysis of articles was conducted to gain insights into diverse enzyme interactions and feed evaluation assessments, from the nutritional science and biotechnology sector.; (3) Results: A total of 36 peer-review papers, which include original, and review articles were selected.; (4) Conclusions: In vitro digestion studies offer a valuable tool for evaluating the digestibility of conventional and alternative feed ingredients, helping to identify sustainable dietary substitutes for fish meal while reducing dependence on live animal trials.

This study assessed the growth performance and economic profitability of juvenile common carp (Cyprinus carpio) cultured on Black Soldier Fly (BSF) Hermetia illucens larval-based diets. The experiment was conducted in a recirculating system. Four isonitrogenous (350 g kg-1 crude protein) and isolipidic (80 g kg-1 crude fat) diets were formulated in which fishmeal (400 g kg-1) and fish oil (30 g kg-1) were simultaneously replaced with a defatted BSF larval meal and BSF larval oil at 0, 25, 50, and 75%. Fish (initial body weight of 96.30±8.35g) were hand-fed at 3% body weight for 7 weeks. The result indicated a significant linear increase (p < 0.05) in mean final weight, weight gain, and specific growth rate (SGR) with higher dietary levels of BSF larval meal and oil. The feed conversion ratio (FCR) decreased linearly with increasing inclusion levels of BSF larval meal and oil. The economic analysis showed a linear decline in profitability with higher dietary levels of BSF larval meal and oil. The findings suggest that BSF larval meal and oil could potentially replace up to 75% of dietary fishmeal and fish oil (300 g kg-1 and 25 g kg-1, respectively) without adversely impacting growth performance and nutrient utilization of juvenile common carp.

Sustainability is becoming increasingly important in the world we live in, because of the rapid global population growth and climate change (drought, extreme temperature fluctuations). People in developing countries need more sustainable protein sources instead of the traditional, less sustainable meat, fish, egg, and dairy products. Alternative sources (plant-based, such as grains (wheat, rice sorghum), seeds (chia, hemp), nuts (almond, walnut), pulses (beans, lentil, pea, lupins), and leaves (duckweed), as well as mycoproteins, microalgae, and insects) can compensate for the increased demand for animal protein. In this context, our attention has been specifically focused on duckweed—which is the third most important aquatic plant after the microalgae Chlorella and Spirulina—to explore its potential for use in a variety of areas, particularly in the food industry. Duckweed has special properties: It is one of the fastest-growing plants in the world (in freshwater), multiplying its mass in two days, so it can cover a water surface quickly even in filtered sunlight (doubling its biomass in 96 hours). During this time, it converts a lot of carbon dioxide into oxygen. It is sustainable, environmentally friendly (without any pesticides), and fast growing; can be grown in indoor vertical farms and aquaculture, so it does not require land; is easy to harvest; and has a good specific protein yield. Duckweed belongs to the family Araceae, subfamily Lemnoideae, and has five genera (Lemna, Spirodela, Wolffia, Wolffiella, Landolita) containing a total of approximately 36–38 recognised species. Duckweed is gaining attention in nutrition and food sciences due to its potential as a sustainable source of protein, vitamins, minerals, and other bioactive compounds. However, there are several gaps in research specifically focused on nutrition and the bioaccessibility of its components. While some studies have analysed the variability in the nutritional composition of different duckweed species, there is a need for comprehensive research on the variability in nutrient contents across species, growth conditions, harvesting times, and geographic locations. There has been limited research on the digestibility, bioaccessibility (the proportion of nutrients that are released from the food matrix during digestion), and bioavailability (the proportion that is absorbed and utilised by the body) of nutrients in duckweed. Furthermore, more studies are needed to understand how food processing (milling, fermentation, cooking, etc.), preparation methods, and digestive physiology affect the nutritional value and bioavailability of the essential bioactive components in duckweed and in food matrices supplemented with duckweed. This could help to optimise the use of duckweed in human diets (e.g., hamburgers or pastas supplemented with duckweed) or animal feed. More research is needed on how to effectively incorporate duckweed into diverse cuisines and dietary patterns. Studies focusing on recipe development, consumer acceptance, palatability, and odour are critical. Addressing these gaps could provide valuable insights into the nutritional potential of duckweed and support its promotion as a sustainable food source, thereby contributing to food security and improved nutrition. In summary, this article covers the general knowledge of duckweed, its important nutritional values, factors that may affect their biological value, and risk factors for the human diet, while looking for technological solutions (covering traditional and novel technologies) that can be used to increase the release of the useful, health-promoting components of duckweed and, thus, their bioavailability. This article, identifying gaps in recent research, could serve as a helpful basis for related research in the future. Duckweed species with good properties could be selected by these research studies and then included in the human diet after they have been tested for food safety.

(1) Background: Water temperature is a key determinant of fish digestion. In vitro methods provide a reliable approach to assess enzyme activity, which is especially important in carnivorous catfish with protein-rich diets. Although the hybrid catfish Clarias gariepinus × Heterobranchus longifilis is widely farmed in Hungary, its optimal temperature for maximizing digestibility remains under investigation.; (2) Methods: Fish were reared at 23 ºC, 25 ºC, and 27 ºC, and stomach and proximal intestine content samples were collected, and it was determined the protease activity (3) Results: No statistically significant differences were observed in enzyme efficiency, crude protease activity (p > 0.05). Despite not significant differences, the stomach and intestinal, protease activity tended to be higher at 25 °C (3.41 ± 0.16 U/mL), and, while in the intestines was higher at 27 °C (2.03 ± 0.27 U/mL). Stomach activity was higher at 27 ºC, at 27 °C (2.03 ± 0.27 U/mL, respectively. (4) Conclusions: Stomach protease activity tended to be higher at 25 °C, while intestinal activity was highest at 25–27 °C. These results may indicate a better starting digestion that supports feed digestion.

This review examines the significance of live feeds in commercial aquaculture industry for production of fish and shrimp larvae, along with various challenges and prospects. Live feeds are an essential food source in larviculture, especially for marine fish, which depend on them for nutrition during the initial days of exogenous feeding. They are palatable, highly digestible, and their movement stimulates natural hunting and foraging instincts, promoting better development, lowering captivity stress, and increasing survival rates. Artemia is the most commonly used live feed in larviculture; however, it has low levels of omega-3 HUFA. Copepods are the most nutritionally rich live feed, containing high levels of DHA and EPA. Despite these benefits, they are less frequently used in larviculture due to technical challenges associated with large-scale cultivation at high densities. The use of live feed is labour-intensive and costly. The feeding period for fish larvae can be shortened using a co-feeding strategy. Microalgae rich in DHA have been utilized to enrich live feeds. Further research is needed to determine the most effective approach to significantly reduce the weaning time of fish larvae from live feed. This will lead to gradual and eventual complete replacement of life feed in the near future.

The objective of the present study was to examine the impact of dietary supplementation with probiotics and yeast cell wall prebiotics on the intestinal microbiota of common carp (Cyprinus carpio). A total of 96 carp, with an average body weight of 932 ± 161 g, were distributed into 12 fish tanks (800 L), with 8 fish/tank. The fish were fed a variety of experimental diets, including a basal diet only (CD) or a basal diet supplemented with the probiotic Pediococcus acidilactici (PA), the yeast probiotic Saccharomyces cerevisiae (SC), or the yeast cell wall prebiotic (YANG) at a concentration of 0.1% (1 g/kg) for a duration of 42 days. At the end of the trial, fish digesta were withdrawn, and the total bacterial community of the gut of common carp was analyzed using Illumina’s NGS targeting the 16S rRNA gene. A Krona phyla richness pie chart showed that 11 bacterial phyla were recorded in fish fed YANG, with the top three phyla being Fusobacteria, Firmicutes, and Proteobacteria. In addition, 10 phyla were identified in fecal samples from carp fed PA, with the top three phyla being Proteobacteria, Firmicutes, and Fusobacteria. Furthermore, nine phyla were recorded for carp fed SC, with the top three phyla being Fusobacteria, Firmicutes, and Proteobacteria. However, carp fed a basal diet exhibited 14 phyla, with the most abundant phyla being Fusobacteriota, Bacteroidota, and Proteobacteria. This study concluded that the tested feed supplements could cause considerable alterations in the composition of the gut microbiome of carps reared in recirculating systems.

A less-explored stressor in intensive recirculating aquaculture systems (RASs) is noise exposure. The noise profile of RASs, including the level and type of noise sources, can influence fish production. In such systems, creating an environment that enhances fish performance via improved welfare is recommended. One possible environmental enrichment method is the use of music. This study aimed to review the effects of acoustic noise as an environmental stressor and music as a potential performance-enhancing tool in teleost fish. As complete elimination of sound sources is not feasible, technological solutions may help improve acoustic environments by considering the perceptual abilities of fish and potential positive responses to music. It is advisable to design systems in which acoustic stimuli have beneficial effects on fish welfare and productivity. Given the limited existing research, further studies are needed to better understand the impact of noise and music in RASs. Insights from such research could lead to welfare improvements and increased economic yields in intensive aquaculture, a critical element of future global food security.

This study examines the sustainability and economic viability of intensive common carp (Cyprinus carpio) production in recirculating aquaculture systems (RASs) in Hungary. Using a deterministic model, the research identifies production costs, profitability, and the critical factors influencing economic efficiency. It also evaluates the impact of key variables, such as the feed purchase price, the market-sized common carp sales price, the specific gross yield, the electricity price, and electricity consumption, on economic performance by using a sensitivity analysis. Primary data were collected from an experimental trial conducted under controlled conditions in Hungary, dividing the production process into three phases: pre-rearing, post-rearing, and market-sized fish production. The unit production cost of market-sized common carp in 2024 was 5.47 EUR/kg, with energy (47.01%) and feed (24.18%) as the main cost drivers. While the sales price covered variable costs, it failed to offset fixed costs, resulting in a loss of 0.41 EUR/kg. The results reveal that while RAS technology offers high productivity and efficient resource utilization, its economic viability is challenged by high initial investment and operational costs. Nevertheless, the study identifies optimization opportunities in feed management, water usage, and electricity efficiency to enhance sustainability and profitability. These findings emphasize the importance of integrating economic, environmental, and technological considerations to advance intensive aquaculture practices.

The African catfish (Clarias gariepinus x Heterobranchus longifilis) is one of the most important fish species in Hungarian aquaculture. The larvae and juveniles are reared at high feeding rates, which can reach up to 10% of the biomass. Intensive feeding results in large amounts of effluent water, directly proportional to the intensity of fish production. The aim of this experiment was to investigate the potential of Common duckweed (Lemna minor) as a biological filter and its nutrient removal capacity during intensive fry rearing of the hybrid African catfish. In a recent study, two experimental recirculation systems, identical in water volume and design, were set up, in one of which duckweed was grown under aquaponic conditions, where the concentrations of nitrogen and phosphorus forms were monitored and the production parameters of the fish were determined. The results obtained from the experiment showed that the use of duckweed as a biological filter improves the water quality of the recirculation system. A significant amount of plant biomass was produced, which mainly reduced the nitrate and orthophosphate concentrations in the system water. As a consequence, the survival of hybrid catfish was improved, which also affected biomass growth, but had no effect on other parameters.

The aim was to investigate the effect of water temperature on digestive enzyme activities of perch, to determine at which temperature their digestion process is more suitable. European perch (Perca fluviatilis) (1 year old, 50-60 g, 10 cm) were kept in recirculation system with the stocking density of 9 kg/m3 in 150 litre-sized-tanks, at 16 degrees C, 18 degrees C, 20 degrees C, 22 degrees C. Fish were kept for 1 week acclimatization, starved for 72 hours before feeding (crude protein: 45%, crude fat: 16%, crude fiber: 2.6%; digestible energy: 18.5 MJ). Feeding was twice, with a 6 hours interval. There were 3 tanks for each proper temperature treatment; every tank contained 100 fish. 10 fish were moved out from all the tanks (30 fish per treatments). Stomach, intestine of fish was separated and their walls were washed with 1 ml of distilled water (pH 2.5), with 1 ml of 50 mM Tris-HCl, containing 0.5 M NaCl, 20 mM CaCl2 (pH 7.8), respectively, to retrieve gastric and intestinal digestive extracts. Extracts were used for pepsin, trypsin. total alkaline proteolytic, lipase, alpha-amylase activity tests. We have succeeded in developing protocol for gaining enzyme-containing extracts to monitor the realistic physiological conditions of perch based on enzyme activity measurements. The protocol was considered to be easy to implement and to provide sufficient enzyme extract to simulate subsequent in vitro digestion. The ambient temperature affected enzyme activities significantly: pepsin (40480.14; 69245.91; 79305.86; 40236.32 U/mg protein), trypsin - (7.77; 9.88; 11.12; 5.42 U/mg protein), total alkaline proteolytic - (1.47; 1.14; 1.25; 0.84 U/mg protein), lipase - (0.40; 1.16; 0.72; 0.76 U/mg protein) and alpha-amylase (0.29; 0.395; 0.98; 1.17 U/mg protein) activities, respectively at 16, 18, 20 and 22 degrees C. Based on protease activities, 18-20 degrees C was chosen to be the most appropriate rearing temperature, which contributes the most to the proper growth of the fish.

The aim of this study was to estimate the occurrence of bacterial infection and contamination in two ostrich-producing farms. Compared to other poultry species, the hatchability of ostrich eggs is especially low. In a quest to identify factors that may affect hatchability, we collected faecal samples from adult birds, as well as eggs with dead-in-shell embryos, dead chicks and swab samples from the surface of the eggs and from the environment. The samples were screened for the presence of bacteria by routine bacteriological culture methods. The most prevalent bacteria, detected in the samples, were Escherichia coli, Bacillus spp. and coliform bacteria, whereas Pseudomonas spp. were less frequently found. The intensity and species compositon of the bacterial contamination was comparable in the two farms. Our results revealed that the bacteria, present in the environment, may likely be transmitted to the surface of the eggs. If they are able to penetrate the shell then the embryos and chicks become infected easily. These findings draw the attention to the special importance of enforcing efficient decontamination and disinfection measures to keep the environment and egg surface free from germs. Besides the appropriate egg treatment procedure, the incubation and hatching technology should also be kept under control.

Pikeperch aquaculture technologies have significantly improved, yet knowledge regarding the adaptation of pikeperch to captivity is very scarce. This study aimed to evaluate the survival, growth, stress response, and immune system function of the F2 generation of pikeperch subjected to pond nursing – Recirculating Aquaculture System (RAS) dry feed adaptation, with either RAS or pond grow-out. F2 generation in this research originated from the broodstock reared in the pond system during grow-out, while F1 originated from wild breeders. Critical points in fish growth were analyzed, including transport of pond-nursed juveniles to RAS at 42 DPH, dry feed habituation (42–52 DPH) and post-habituation (52–64 DPH) phase, as well as the on-grow/grow-out (64–154 DPH) phase. Our results showed better growth and survival of the F2 generation in comparison to F1 in pond grow-out. However, the F1 generation was superior in conventional RAS grow-out. Nevertheless, during RAS dry feed habituation, F1 fish were inferior, both in terms of growth and survival, in comparison to F2 fish. Stress and immunological marker analysis revealed higher stress sensitivity, accompanied by stronger immune system activation, in F2 generation in comparison to F1. This was manifested as higher cortisol and immunoglobulin response after moving fish from one system to another. Hypothetically, stronger stress and immune response might have induced better dry feed adaptation during the habituation phase in RAS, and better control of microbial growth in the grow-out environment with a higher microbial load, such as pond. On the other hand, according to the same hypothesis, in a cleaner grow-out environment such as RAS, fish with a weaker cortisol and immunological response would be at an advantage, since these fish are expected to have a richer intestinal microbiota that would eventually support better food digestion and growth. Assumed selection points shaping pikeperch response to farming have been discussed.

The extracts of whole plants or specific organs from different plant species are gaining increasing attention for their phytotherapy applications. Accordingly, we prepared standardized gemmotherapy extracts (GTEs) from young shoots/buds of olive (Olea europaea), sweet almond (Prunus amygdalus), and black mulberry (Morus nigra), and analyzed the corresponding phytonutrient profiles. We identified 42, 103, and 109 phytonutrients in the olive, almond, and black mulberry GTEs, respectively, containing amino acids, vitamins, polyphenols, flavonoids, coumarins, alkaloids, iridoids, carboxylic acids, lignans, terpenoids, and others. In order to assess the physiological effects generated by the GTEs, we developed a translational nutrition model based on Drosophila melanogaster and Cyprinus carpio. The results indicate that GTEs could influence, to a variable extent, viability and ATP synthesis, even though both are dependent on the specific carbohydrate load of the applied diet and the amino acid and polyphenol pools provided by the GTEs. It seems, therefore, likely that the complex chemical composition of the GTEs offers nutritional properties that cannot be separated from the health-promoting mechanisms that ultimately increase viability and survival. Such an approach sets the paves the way for the nutritional genomic descriptions regarding GTE-associated health-promoting effects.

This research explores the potential of using common duckweed (Spyrodela polyrhiza) as a feeding substrate and supplement for yellow mealworm production. Duckweed is known for its high content of protein (20–35%) and essential amino acids. This study aims to assess the effect of the combination of semolina and duckweed as a feeding substrate for yellow mealworm larvae (Tenebrio molitor). The experiment involved different combinations of semolina and duckweed in varying proportions. The treatments included 100% semolina (S), 75% semolina + 25% duckweed (S75D25), 50% semolina + 50% duckweed (S50D50), 25% semolina + 75% duckweed (S25D75), and 100% duckweed (D). Over a six-week period, the production parameters, nutrient composition, amino acid composition, and fatty acid composition of the yellow mealworms were measured and analyzed. The results demonstrate that S75D25 and S50D50 feed combinations were recommended due to their positive effects on production parameters and nutrient composition. Although the D substrate exhibited the highest crude protein content, yellow mealworm larvae did not grow on this substrate. The inclusion of duckweed in the feed had no significant effect on the fatty acid composition of the mealworms, while substrates S25D75 and D induced an improved amino acid composition. In conclusion, incorporating duckweed into the feeding substrate can enhance the production parameters and nutrient composition of yellow mealworms.