Fish Farming Research Articles

Morphological and molecular assessment of muscle metacercariae infecting tench Tinca tinca from fish farms and wild populations in Germany.

Fish can be infected with metacercariae (the final larval stage) of different species of potentially zoonotic digenetic trematodes (flukes). The fish-borne zoonotic trematodes thus compromise food safety and present a major threat for human health. Reducing the risk of human infections requires careful assessment and accurate taxonomic identification of these parasites. Here, we analysed metacercariae in muscle tissue of tench (Tinca tinca), sampled between March and September 2022 from three fish farms and three natural waterbodies in Germany. Whenever possible, we combined morphological and molecular data from the very same individual metacercariae using mitochondrial cytochrome oxidase c subunit 1 (cox1) and nuclear internal transcribed spacer 1 (ITS1) for species identification. Three morphotypes of metacercariae were found in the muscle of tench, corresponding to the trematode species Pseudamphistomum truncatum Rudolphi, 1819 (Opisthorchiidae), Hysteromorpha triloba Rudolphi, 1819 (Diplostomidae), and Paracoenogonimus ovatus Katsurada, 1914 (Cyathocotylidae). The high prevalence of metacercariae of P. truncatum and P. ovatus, both with zoonotic potential, poses a risk for human infections if undercooked or raw tench is consumed.

Assessment of Commercial Fish Feed Usage and Market Access among Fish Farmers in Manipur, India

Fish feed constitutes the largest share of operational costs often up to 60 % in aquaculture and plays a very important role in determining the overall growth, health, and productivity of cultured fish. A structured questionnaire-based survey was conducted among 50 fish farmers across five districts of Manipur namely Imphal East, Imphal West, Thoubal, Kakching, and Bishnupur to assess the availability, pricing, and usage of commercial fish feed. The study aimed to understand feed preferences, access to subsidies, and supply-related challenges. This study showed that only 20% of respondents reported easy availability of commercial feed in remote areas, while 88% noted price hikes due to economic blockades. A majority of farmers preferred feeds (Crude protein range-28 to 30%) and floating feed types, mainly for Indian Major Carps. Only 8% reported receiving subsidized feed. The findings highlight limited feed access in remote areas, inadequate policy outreach, and pricing challenges. The study suggests improving distribution infrastructure, increasing subsidy awareness, and promoting local, low-cost feed innovations to enhance aquaculture sustainability in Manipur.

Таксономия задач математического моделирования в аквакультуре

The current stage of global aquaculture development is characterized by steady positive dynamics of production indicators observed over the past 30 years; Russian fish farming demonstrates similar growth trends. The industry is undergoing a period of technological transformation driven by three key factors: the massive adoption of mi-crosensory monitoring technologies, the development of specialized software, and the integration of Internet solutions into production processes. At the same time, the competitiveness of the aquaculture market is steadily growing, and the amount of data that fish farmers have to manage is rapidly increasing. Mathematical modeling is becoming crucial for the transition from empirical methods of aquaculture management to scientifically based production processes. The methodology of mathematical modeling finds application in solving a wide range of industry tasks: from the development of optimal strategies for the exploitation of aquatic biological resources to forecasting environmental risks in cage farms. At the same time, many tasks are interrelated: some are special cases of others, differ in scale or use similar mathematical methods. The purpose of the work is to systematize and classify mathematical modeling problems in aquaculture. Within the framework of this study, a comprehensive analysis of world scientific publications in peer-reviewed sources over the past 50 years has been carried out. The developed taxonomy of tasks related to mathematical modeling, covering bioeconomical, ecological and engineering models, is described. In total, the analysis included 20 of the most common modeling tasks, ranging from analyzing the efficiency of fish farming and economic analysis of fish farming activities to selecting the most suitable fish farming area and assessing the strength of cages.

Аквакультура радужной форели: мировые тенденции, российская практика и региональные перспективы развития

According to the FAO, the world is gradually transitioning from industrial fishing to aquaculture, which accounted for 130.9 million tons of fish in 2022. Data on the state of aquaculture and the prospects for its development in the world, in the Russian Federation, in particular the Vologda oblast, are presented. The Russian Federation has a huge fish farming potential. In 2023, salmon fish occupy the first place in the territory of the Russian Federation in terms of commercial aquaculture production. One of the common species for commercial fish farming is rainbow trout (Oncorhynchus mykiss). The widespread development of industrial trout farming in Russia is possible due to the suitable geographical location and favorable climatic conditions for breeding rainbow trout. Since the first half of the 20th century, the breeding of commercial fish species has been the most important direction for the development of fisheries in the reservoirs of the Northwestern Federal District of Russia, and therefore at least 25 species of fish, including rainbow trout, have been introduced into the reservoirs of the Vologda Region. Currently, there are 15 operating enterprises in the Vologda Region and 13 more commercial fish farming enterprises are planned to operate. The ecology of rainbow trout is considered, and a comparative characteristic of the favorable habitat conditions of this species with the conditions of the reservoirs of the Vologda region is given. It is noted that the reservoirs of the Vologda region are suitable for breeding rainbow trout in aquaculture conditions according to various criteria.

An integrating RAG-LLM and deep Q-network framework for intelligent fish control systems

The fish farming industry is advancing by adopting technologies designed to enhance efficiency, productivity, and sustainability. This study investigates integrating a Retrieval-Augmented Generation Large Language Model (RAG-LLM) with a Deep Q-Network (DQN) in autonomous aquaculture. It compares their performance to traditional expert-led methods and other AI-based systems. The developed autonomous system employs ensemble learning of RAG-LLM and DQN, incorporating IoT devices to thoroughly monitor feeding schedules, disease management, growth, and water quality parameters. This integration allows the system to generate optimal policies through majority voting, leveraging pre-trained LLM knowledge to improve initialization conditions and accelerate learning convergence. The hybrid approach of RAG-LLM and DQN demonstrates superior growth rates and rapid stabilization of automation policies. This highlights its potential to enable non-experts to manage fish farms and efficiently scale production for global food sustainability.

Abundance and transmission of antibiotic resistance and virulence genes through mobile genetic elements in integrated chicken and fish farming system

Integrated chicken and fish farming systems, common in Bangladesh, present significant public health risks due to the spread of antimicrobial resistance genes (ARGs) and virulence factors (VFGs) through mobile genetic elements (MGEs). This study employs metagenomic sequencing to explore the diversity and abundance of ARGs, VFGs, and MGEs in various environmental samples from these farming systems. A total of 384 ARGs were detected, with tetracycline resistance genes such as tetM and tetX being the most abundant, alongside macrolide-lincosamide-streptogramin and aminoglycoside resistance genes. Droppings harbored the highest proportion of ARGs (62.2%), whereas sediment served as a reservoir for multi-metal resistance genes. Virulence factors associated with immune modulation, such as pvdL and tssH, and biofilm formation genes like algC were particularly prevalent in sediment and droppings. Among MGEs, plasmids and transposons like Tn6072 and Tn4001 were the most abundant, playing a critical role in horizontal gene transfer. Bacterial genera including Bacteroides, Clostridium, and Escherichia were strongly associated with MGEs, indicating their role in the dissemination of resistance and virulence traits. Statistical analyses revealed significant differences in the abundance of ARGs, VFGs, and MGEs across sample types, with sediment and droppings identified as hotspots for gene exchange. These findings underscore the urgent need for improved antibiotic stewardship and waste management practices to limit the spread of antimicrobial resistance and pathogenic bacteria within integrated farming environments.

Технология рыборастительного батончика с СО2-экстрактами лемонграсса и элеутерококка

An original technology of a specialized fish-growing bar enriched with CO2 extracts with antioxidant properties has been developed. The chemical composition of naked carp, scaly carp, potatoes, carrots, lentils, CO2 lemongrass and eleutherococcus extracts has been studied. A structural scheme and formulations of fish-growing bars have been developed. A study was carried out to assess the relevance of works devoted to the creation of multicomponent fast food products. The sequence of technological stages of processing into minced meat of a hybrid of naked carp grown at the Shaparievsky fish farm in the Slavyansky district of the Krasnodar Territory is presented. Among the vegetable raw materials, the objects of the study were lentils of the Donskaya Krasnozernaya variety, potatoes of the Golubizna variety and carrots of the Lakomka variety. Cryopowder from carp bones was used as a mineral concentrator. It has been established that the most effective way of processing medicinal plants for food additives is the method of subcritical CO2 extraction. For the first time, CO2 lemongrass and eleutherococcus extracts have been included in the formulation of fish-growing products, which has increased the antioxidant properties of the finished product. Such a fish-growing bar has a specialized purpose, for example, as a sports nutrition product.

Experimental study on seakeeping and dynamic motion performance of a novel concept of fish farming vessel

Experimental study on seakeeping and dynamic motion performance of a novel concept of fish farming vessel

Fish food security: analyzing the economic and environmental variables

The research aims to assess fish production, consumption, self-sufficiency rates, and deficits in fish food in Saudi Arabia from 2001 to 2022. It will also evaluate local production sufficiency and import duration and analyze economic and environmental factors influencing fish food security over this period. The study employs descriptive statistical analysis to identify trends, patterns, and outliers in the data, using measures such as means, standard deviations, and growth rates. To investigate the relationships between variables, the research applies the Error Correction Model (ECM), a methodology designed to capture both short-term dynamics and long-term equilibrium relationships. The ECM analysis is supported by unit root tests (Augmented Dickey-Fuller and Phillips-Perron tests) to assess stationarity and cointegration tests to confirm stable long-term connections. Ordinary Least Squares (OLS) estimation techniques are used to derive model coefficients, while additional diagnostic tests ensure the robustness and reliability of the results. Key findings include annual growth rates of 5.8% for fish output, 4.0% for fish imports, and 4.0% for local consumption. The fish self-sufficiency rate has significantly increased at 6.7% per year. However, the fish food gap, local production sufficiency period, and proportion of imported fish consumed daily are growing at rates of 2.7%, 10.9%, and 1.6%, respectively. The error correction model indicates an error correction coefficient of approximately 0.54, statistically significant at 1%. This coefficient represents the percentage of imbalance in the food security coefficient for fish that can be adjusted yearly, with a correction period of about 1.85 years. Thus, it takes roughly 1 year and 10 months for the food security coefficient to return to equilibrium after deviations occur. Based on these findings, the report recommends three actions: increasing modern fishing vessels, funding fish farming initiatives, and reducing environmental pollution to enhance self-sufficiency and outpace population growth.

Технологический потенциал вторичных ресурсов переработки осетровых объектов товарной аквакультуры Астраханской области

The share of commercial aquaculture sturgeon objects accounts for an average of 10% of the volume of fish farming by enterprises of the fisheries complex of the Astrakhan region from 2020 to 2024. The number of commercial aquaculture sturgeon objects grown in 2024 is 2.7 tons. In terms of commercial aquaculture production volumes for 2024, sturgeon is in 4th place (1,601 tons) after silver carp, carp and grass carp. The range of cut frozen sturgeon products manufactured by the enterprise OOO Astrakhan Fish Breeding Company Beluga is represented by the following types of products: gutted sturgeon with head, carcass, fillet, steak, piece, heads and fish soup sets. The cost of sturgeon products in 2025 amounted to 450 to 2,500 rubles, the lowest cost was noted for sturgeon heads, the highest for steaks and skinless fillets. The stability of the enterprise's range of frozen sturgeon products is 90%, novelty is 10%. The mass yield of edible parts when cutting a sturgeon carcass (chilled from frozen raw materials) is 67%, inedible parts – 31%. If the skin is preserved, the yield of the edible part when cutting the carcass will increase to 83.64%. The skin, scutes, spine and fins are secondary collagen-containing resources, the targeted use of which is possible with deep processing and separation of the component composition with the release of collagen proteins. The mass yield of sturgeon head processing products: gill heads – 85.08%; gills – 10.83%; the proportion of edible parts of sturgeon heads from 25.14 to 51.91% of the boiled head weight; cartilage – 15.31% of the frozen glazed head weight and 24.41% of the boiled head weight. Inedible parts of sturgeon heads include bones, which make up 10.76% of the boiled head weight. Sturgeon heads are a promising object of industrial processing of edible parts for food purposes. It is rational to develop a comprehensive technology for processing sturgeon heads with the production of a wide range of products for various purposes.

In VIVO MODULATORY EFFECT of MALACHITE GREEN on CYTOCHROME P450 AND ANTIOXIDANT ENZYME ACTIVITIES in RAINBOW TROUT LIVER

Malachite green is a mutagenic and carcinogenic chemical used as a dye in textile and paper industry and in fish farms against ectoparasites, bacterial and fungal infections. Aquatic organisms are at risk of malachite green exposure. In this study, our aim was to determine the effect of two different doses of malachite green on cytochrome P450 system and antioxidant system in rainbow trout (Oncorhynchus mykiss). For this purpose, 24 fish were randomly divided into three groups: the control, the 0.1 mg/L malachite green treatment group and the 0.5 mg/L malachite green treatment group. Highly elevated 7-ethoxyresorufin-O-deethylase activities (EROD) were measured in fish treated with 0.5 mg/L malachite green. 7-pentoxyresorufin O-depentylase (PROD) activities increased with increasing doses of malachite green. Catalase (CAT) and glutathione reductase (GR) activities in the 0.1 mg/L malachite green administration group were higher than those in the control group. Erythromycin N-demethylase (ERND) and glutathione S-transferase (GST) activities were not significantly affected by malachite green treatment in either treatment group. The results of this study clearly demonstrate that malachite green has a modulatory effect on EROD, PROD, CAT, and GR activities in rainbow trout.

Evaluating the Feasibility of Integrating Climate-Smart Technologies at BAU-Adjacent Villages in Mymensingh, Bangladesh

Agriculture remains a vital pillar of Bangladesh’s economy and rural livelihoods, employing nearly half of the workforce and contributing significantly to GDP, despite the nation's shift toward industrial and service sectors. That's why we are also attempting to shift from conventional practice to modern use of technology in order to cope with the situation. Because of this, it is essential to examines the adoption of modern and traditional agricultural methods in crop farming, livestock farming, and fish farming system. which will help us to identify the level of adoption, problems faced by farmers, and sustainable solutions that can increase agricultural productivity. Data from 219 farmers are collected through a quantitative survey and descriptive statistics are used for getting the result. The findings indicate that mechanization is gradually gaining ground, especially in using tractors, power tillers, and deep tubewells in crop cultivation. However, the traditional implements and practices still prevail because of the scarcity of modern technology, hands-on training, and high cost. In livestock, the situation improves a little as far as artificial insemination is concerned, though it still relies on conventional methods of feeding; fish farming has mainly adopted polyculture without following modern aquaculture technologies. The main constraints noted are financial, lack of availability of quality seeds and machinery, infestations, and lack of proper training. To support sustainable agriculture, it is important to offer targeted training programs, strengthen agricultural extension services, and improve farmers’ access to affordable credit, quality inputs, and subsidies for machinery and materials. Promoting climate-smart technologies is also essential. Overcoming existing challenges will require stronger government support and better infrastructure. J Bangladesh Agril Univ 23(2): 211-221, 2025

Occurrence of internal nematode parasites and condition factor of Nile tilapia (Oreochromis niloticus) fish species from Agneby river, Cote divoire

The Nile Tilapia Oreochromis niloticus fish is a freshwater cichlid that is indigenous to the Nile basin and is one of the world’s most important food fishes. It is a fish that is very common in Ivorian waters, used for food, and widely utilized in fish farming. However, it is susceptible to infections caused by nematode parasites, which can negatively impact the fish's condition and there are not well known. A study was conducted from February 2023 to March 2024 to determine the epidemiological indices of internal nematode parasites in Nile tilapia in two stations of the Agneby River. The study focused on 450 specimens of this fish, captured using gill nets of various sizes. The gastrointestinal tract fauna of this fish consisted of Capillaria pterophylli, Camallanus polypteri, Eustrongylides sp. and Contracaecum sp. The fish caught in Agboville station were the most parasitized. Seasonal variations in the infestation of this fish by parasitic nematodes have been observed. Generally, the largest and heaviest fish had more parasitic nematodes. The impact of host sex was observed for all nematode parasite load. The study indicated that these parasites have a negative impact on the body condition of this fish. The presence of nematodes causing zoonoses poses a public health risk for people living near this river who have developed the habit of consuming raw or undercooked fish. Therefore, awareness creation activities and control of fish parasites should be conducted in the study river.

Assessment of the beneficial effect of using fresh Azolla filiculoides in the productivity of the integrated rice-fish system at Bonoufla, Cote divoire

The objective of this study was to determine the effect of Azolla filiculoides on the growth parameters of rice Wita 9 and tilapia Oreochromis niloticus in integrated rice-fish culture. Fingerlings (6.11 ± 0.19 g; 12 fingerlings/m²) were placed in the ponds transplanted with 14-day-old rice seedlings. These seedlings were transplanted two by two in clusters with a spacing of 20 cm between them and 25 cm between rows. Two treatments of fresh A. filiculoides and rice bran were applied in these ponds to compare the changes in fish zootechnical and rice agronomic parameters with a control after 3 months of production. The data collected showed that the best rice seedling growth and fish performance were obtained with the addition of A. filiculoides. Yields were also higher with the same treatment (6.97 ± 0.08 T/ha for rice and 166.13 ± 26.94 Kg/ha for fish) compared to the control and rice bran treatments. The use of Azolla fern could thus constitute an alternative of choice in front of the costs of the conventional inputs used in fish farming and rice farming in Côte d'Ivoire.

Application of Zeolite (Clinoptilolite) Combine with Leonardite for the Removal of Ammonia in Different Sizes Microparticulate Fish Feed

In this study, the effect of feed size on ammonium release from non-consumed feed in aquaculture systems were investigated. In the 11-day study, nine experimental groups were formed in triplicates. Three different sizes of microparticule feed (F1: 100-200 µm, F2: 200-300 µm and F3: 300-400 µm) with the same nutrient content were used in the experiment. The first three groups (CF1, CF2, CF3) were organized as control groups and no adsorbent mixture was added to these groups during the experiment. In the other three groups (ABF1, ABF2, ABF3), the adsorbent mixture was added at the beginning of the experiment together with 3 different sizes of feed used in the experiment. In the last three groups (AF1, AF2, AF3), the adsorbent mixture was added to the experimental environment after the 7th day together with 3 different sizes of feed. At the end of the 11-day experiment, the highest and lowest mean ammonium levels were identified in the CF1 (25.85 ± 2.93 mg L-1) and ABF1 (4.47 ± 0.71 mg L-1) groups, respectively. The study concluded that the size of the fish feed was correlated with the release of nitrogenous compounds from the feed. Consequently, it can be recommended that larger particles should be preferred in fry fish farming, provided that the feed size is suitable for the mouth opening. Furthermore, it was determined that the use of adsorbent mixtures, particularly at the outset of the experiment (when nutrient concentrations were low), was highly effective in reducing ammonia values.

Репродуктивні показники плідників європейського харіуса (Thymallus thymallus Linnaeus, 1758), адаптованих до умов штучного вирощування

Purpose. To investigate reproductive parameters, namely: fecundity, size and weight of eggs, embryo survival to the “eye” stage in firstly and repeatedly spawning groups of third-generation European grayling grown and adapted to artificial conditions. Methodology. The work on the reproduction of European grayling was carried out at the State Institution of Trout Hatchery “Lopushno”. Anesthesia of brood fish was carried out with a natural anesthetic - clove oil at the rate of 1 ml/10 L of water. Measurement of length and weight were carried out on live fish. Based on the results of measurements, an analysis of the obtained values was performed and the productive characteristics of brood fish were determined. Fertilization of eggs was carried out by the “semi-dry” method. De-gluing of fertilized eggs was carried out by washing with clean water for two hours. Findings. The average weight of age-2, 3, and 4 European graylings used in spawning was 82.32 g, 126.5.4 g and 238 g with an average length of 20.7 cm, 23.4 cm and 28.2 cm, respectively. The results we obtained from 2019 to 2021 showed that under the conditions of the Lopushno farm, European grayling spawners mature en masse at age-2, with the average weight of two-year-old females ranging from 65 to 100 g with an average length of 18.0 to 23.5 cm. Ovulation of eggs in first-spawning females occurred without artificial stimulation. The average working fecundity of females was: age-2 – 597 eggs, age-3 – 1309 eggs, age-4 – 2950 eggs. Fertilization of eggs was 50%. Originality. A comprehensive analysis of productive and reproductive parameters in third-generation brood European grayling grown in artificial conditions was conducted. A number of factors were identified that may influence the development of high-quality eggs during the creation of broodstocks in controlled conditions of fish farms. Practical Value. The data obtained during the study will be used as the basis for preparing measures for the artificial reproduction of salmonids in the Carpathian region. Keywords: eggs, females, males, length and weight, working and relative fecundity.

Knowledge, attitudes, and practice of fish farmers towards eco-pharmacovigilance for aquaculture discharge of pharmaceutical contaminants from a One-Health perspective: a cross-sectional study in Wuhan area of China

ABSTRACT Veterinary pharmaceuticals widely used in aquaculture would finally enter into the environment, then adversely affect the “One-Health” trilogy (environmental, human, animal health). As a source-control measure for pharmaceutical pollution, the eco-pharmacovigilance (EPV) has been put in place to control discharge of medicinal products for human use. To further implement EPV for veterinary pharmaceuticals, it is necessary to examine the related anthropogenic activities among key stakeholders in veterinary pharmacovigilance, such as farmers. This study conducted a One-Health assessment of knowledge, attitude, and practice regarding EPV for aquaculture discharge of pharmaceuticals among 273 fish farmers in Wuhan, China. Mean knowledge score was 2.21 ± 1.29 out of 10. Most respondents expressed positive attitudes, but also lack of appropriate practices regarding aquaculture discharge of pharmaceutical contaminants and its EPV control. Concern about economy and input cost was identified as the top perceived barrier to eco-friendly use and disposal of veterinary pharmaceuticals, chosen by 26.7% respondents. Moreover, 62.3% farmers were aware of their responsibilities for reducing aquaculture discharge of veterinary pharmaceuticals, however, 45.1% tend to adopt a wait-and-see approach. Data emphasized an urgent need to provide related education and training. EPV measures for aquaculture discharge of pharmaceuticals should be implemented in an economical manner.

A framework for measurement and modeling of sea spray frequency: A probabilistic approach and a synthetic data‐based machine‐learning method

Abstract Collecting field data is crucial for developing reliable models to estimate ice accumulation from sea spray icing, a phenomenon that significantly impacts the safety and efficiency of marine operations in cold regions. This study evaluates the performance of the SPRICE sea spray sensor equipment in gathering detailed spray data related to the phenomenon, with a present focus on measuring and modeling the spray frequency parameter, which is a key term in icing estimation models. Data were obtained from a fish farm cage in Northern Norway, yielding approximately 2000 data points on spray frequency and corresponding meteorological parameters, significantly surpassing data collected with previous methods. This research underscores the significance of precisely modeling critical parameters in icing estimation models to enhance accuracy, thereby improving the safety and efficiency of marine operations. To address the complexity and stochastic nature of spray generation, which depends on meteorological conditions and structural responses, two modeling methodologies are proposed: a probabilistic approach adapted from Forest et al., and a tree‐based machine‐learning model (CatBoost) trained on augmented synthetic datasets derived from field observations. The probabilistic model offers a conservative and straightforward estimation method, while the machine‐learning model demonstrates a significant improvement in predictive performance, effectively capturing the full range of the observed spray frequency values.

Long-term assessment of benthic ecological status in sediments affected by offshore aquaculture: The case of the Republic of Cyprus.

Long-term assessment of benthic ecological status in sediments affected by offshore aquaculture: The case of the Republic of Cyprus.

Effects of pollution on ecologically and economically important organisms of the Salish Sea.

Effects of pollution on ecologically and economically important organisms of the Salish Sea.