Growth Of Aquaculture Research Articles

A holo-omics analysis shows how sugar kelp can boost gut health in Atlantic salmon

The projected growth of Aquaculture requires continuous optimisation of feeding regimes, especially in enhancing disease resilience through immunostimulating feed supplements. Seaweed has been introduced as a promising supplement due to its proposed immunostimulant effects, while mitigating carbon emissions and marine eutrophication. Two separate growth trials were performed to evaluate the effects of a seaweed supplement, focusing on a closed land-based RAS system with fish growing from ∼300–600 g and an open water net-based trial with fish growing from ∼500–2500 g. A multi-omics approach was taken to investigate the effect of using up to 2 % fermented sugar kelp (Saccharina latissima) as a supplement on the growth performance and gut health of Atlantic salmon (Salmo salar L.). Standard growth metrics and quality indicators were coupled with multi-omics data for the host intestinal transcriptome, intestinal metabolome, and intestinal microbiome. Levels of iodine and heavy metals in the fish fillets resulting from seaweed inclusion were evaluated. Seaweed additives up to 2 % had no negative impact on the salmon growth performance or other health parameters. While concentration of iodine increased with seaweed addition, all levels remain below recommended thresholds. Furthermore, gut transcriptome analyses of 179 individuals revealed multiple indications for an immunostimulant effect of seaweed, including overexpression of the mucin biosynthesis and pyrimidine metabolism pathways related to mucus production and intestinal homeostasis. Genome-resolved metagenomics revealed a core microbiome dominated by Mycoplasma, Photobacterium, and Brevinema species. Interestingly, the assembled genomes of these three core species had consistently higher levels of genome erosion and gene loss compared to other present species suggesting host adaptation. Further, reduced prevalence of known pathogens such as Aliivibrio highlights a potential protective effect of seaweed by impeding growth of opportunistic pathogens. Results suggest that supplementation of up to 2 % fermented seaweed can increase feed efficiency, stabilise the intestinal microbiome and potentially increase resistance against known pathogenic bacteria including Aliivibrio species.

Effects of temperature and salinity on the LC-PUFA biosynthesis and composition of the nereid polychaete Hediste diversicolor fed side streams

The rapid growth of aquaculture has prompted the exploration of alternative and sustainable feed ingredients. Polychaetes, such as Hediste diversicolor, offer promise in the circular economy due to their ability to recycle waste materials from bioindustries and convert low nutritional value fatty acids (FA) into eicosapentaenoic (EPA) and arachidonic (ARA) acids. This study explored the combined effect of temperature and salinity on growth and LC-PUFA biosynthesis in H. diversicolor fed on a side stream diet (33% sludge from salmon aquaculture (AS) and 66% solid-phase digestate from biogas production (SBD)). Polychaetes were cultured for 28 days along a 5-step temperature and salinity gradient ranging from 7.7 to 17.9 °C and 5 to 40 psu, respectively. Growth was highest at high temperatures (≥ 14.3 °C) and salinities (≥ 35 psu). The FA composition remained relatively stable across different culture temperatures, while salinity exhibited higher levels of n − 3 PUFA and n − 3 LC-PUFA at lower salinities (5 and 15 psu) compared to higher salinity (35 psu), mainly driven by EPA. This suggests that salinity may exert a more pronounced effect than temperature on the FA profiles of H. diversicolor. Despite low temperature and high salinity (40 psu) significantly upregulating the expression of elongase and desaturase genes, this was not translated into higher LC-PUFA. Remarkably, polychaetes exhibited high levels of n − 3 and n − 6 LC-PUFA, even when fed a diet deficient in such FA. These findings highlight the potential of H. diversicolor for LC-PUFA biosynthesis, positioning this species as a promising candidate for producing high-nutritional-value ingredients for aquafeeds.

Water quality assessment for aquacultivation in Quang Ngai city, Quang Ngai province

Aquatic product development and growth are significantly influenced by the water supply used for aquaculture. Evaluating the water quality available for this activity is vital since Quang Ngai city has been a major hub for the growth of aquaculture in Quang Ngai province. Twelve surface water quality parameters were monitored and analyzed at eight sampling points in the river basins of An Nghia and Tinh Khe communes from May to September 2023. The Water Quality Index (WQI) was calculated, and methods including Principal Component Analysis (PCA), calculation of environmental variable weights based on principal components (PC), and Pearson correlation were used to assess the correlation of the investigated factors. In the river basin of An Nghia and Tinh Khe communes, 12 criteria for the assessment of surface water quality were tracked and examined using 8 sampling locations between May and September in 2023. The degree of linkage was assessed using principal component analysis (PCA), weighting environmental factors based on principal components (PC), and Pearson correlation. The water quality index (WQI) was calculated between the factors of the research. The findings show that: (1) The parameters exceeded the permitted limit: DO, Alkalinity, NH4+, TP, Vibrio SPP, Coliform, TOC, and TN. The two metrics with the greatest levels of pollution among them are Vibrio SPP and NH4+. The WQI index ranges from 52-74 and is within the average water quality range (51-75); (2) PCA analysis reveals that only the first two principal components, PC1 and PC2 can account for 74.39% of the variance, with NH4+ (0.089) having the highest weight; (3) NH4+ and Vibrio SPP content have a strong correlation (r = 0.95), indicating that both of these parameters can be used to evaluate water quality in the study area in general.

Economic Impact of Periphyton-Based Stunted Fingerling Production in Arunachal Pradesh, India

Non availability of right type quality seed at right time in required quantity is major bottleneck for the growth of aquaculture in Arunachal and major portion of seed are being import from other nearby state especially Assam in particular. To make availability of good quality seed at right time having a regional acclimation for a longer duration in far flung areas of the state, the present investigation was conducted on low cost Periphyton (grown on paddy straw) based stunted yearling production technology to improve the survival and health of stocked material and their economic impact on the fish farmers of district West Kameng during 2018-2021. The average values of pond water quality parameters were observed to vary between both the culture ponds with a significant seasonal differences at all the sites and there were found a greater difference in average survival rate of both the commodities i.e. table size fish as well as stunted yearling during whole culture period. The involved cost of cultivation was recorded higher Rs. 4,70,000 / ha in stunted yearling culture in comparison to Rs.424,940/ha in thetable size carp culture while average gross benefit was just opposite, recorded higher Rs. 6,90,000/ ha in stunted yearling culture in comparison to Rs.199,960/ ha in table size carp culture with the same trend in BCR i.e. 2.46 for stunted fingerling production and 1.47 in the production of table size fishes respectively.

Mapping aquaculture in inland continental areas of Brazil using machine learning on the Google Earth Engine

Aquaculture has played a significant and growing role in the provision of food, food security, and job creation, while simultaneously establishing itself as an important agricultural activity subject to increasingly stringent market practices. The generation of spatial information on aquaculture activity in Brazil can support more assertive planning of new enterprises as well as enable the monitoring of this activity over time, fulfilling an agenda of sustainable aquaculture growth in the country. The aim of this article was to map aquaculture areas in the state of Paraná (Brazil) by developing an automated methodology for the extraction of aquaculture ponds. The methodology was implemented on the Google Earth Engine (GEE) platform and utilized satellite images with a spatial resolution of 4.77 m from Norway’s International Climate and Forest Initiative (NICFI) Program – Planet. The process involved pixel-oriented classification of satellite images and the utilization of the Random Forest (RF) algorithm for classification, based on 1200 training samples. The accuracy of the mapping and the algorithm was evaluated using Producer Accuracy (PA), User Accuracy (UA), and Overall Accuracy (OA). The mapping achieved an OA of 0.87, with a PA of 0.89 and a UA of 0.96 for the aquaculture class, and a PA of 0.66 and a UA of 0.41 for the non-aquaculture class. 42,369 aquaculture ponds were identified in the study area, covering a total area of 11,515 ha. The ponds had sizes smaller than 0.7 ha and non-circular shapes (compactness 0.70). Around 40% of the identified aquaculture tanks were concentrated in just two out of the ten analyzed mesoregions, accounting for 40% of the water surface area used for aquaculture in Paraná. Considering that the results obtained show potential to fill the gap in geospatial information about state aquaculture, our methodology would provide a broad understanding of the state’s aquaculture framework, definition of regions with capacity for the expansion of aquaculture ponds, accuracy in estimating the state’s productive space, monitoring the improper expansion of aquaculture areas, as well as establishing locations where the pressure on water resources by aquaculture prevents the expansion of this activity. Therefore, this study could benefit public and private organizations, and other stakeholders, by systematically monitoring aquaculture production in the country’s leading fish farming state, contributing to assertive decisions in regions where aquaculture production needs to expand sustainably.

Popularity and parity assessment for more inclusive and balanced aquaculture development

Aquaculture, a rapidly expanding food production system, holds promise for improving global food security and resilience. However, imbalanced growth has led to a highly uneven distribution of aquaculture production among countries, a concern that has not been comprehensively examined. This paper fills this knowledge gap by developing an innovative indicator system to assess this issue based on aquaculture development in ~ 200 countries over five decades. The system utilizes the “effective number of countries” (ENC) as a basic measure of production distribution and extends it into two novel indicators, popularity and parity, to gauge inclusiveness and balance. The assessment from 1970 to 2020 reveals that aquaculture has become a global enterprise, operating in nearly 90% of countries. Nevertheless, there is still substantial potential for growth in aquaculture popularity across most of 43 species groups examined here. Regarding concerns over persistently imbalanced aquaculture growth, our assessment reveals that aquaculture parity increased during 1970–2020 in the majority of 85 country groups examined here, including 18 of 27 regions and subregions. Global parity is also on the rise in the new millennium (2000–2020). However, the global aquaculture parity remains considerably lower than those of capture fisheries and terrestrial meat production. This suggests that imbalanced global aquaculture development cannot be solely attributed to countries’ comparative advantages. This extraordinary imbalance could compromise global food security and food system resilience, but it also signifies untapped growth potential. Mainstreaming aquaculture popularity and parity as policy indicators can foster more inclusive and balanced development and unlock this potential. The proposed indicator system can be applied across diverse sectors and scales, contributing to a broader and refined understanding of the dynamics within the global food system.

Effect of Lactobacillus Probiotic Supplement on Growth and Haematological Performance of Indian Major Carp Labeo rohita

The influence of probiotics bacteria Lactobacillus acidophilus improves the survival, growth, and Hematological performance of the Indian major carp Rohu (Labeo rohita). After acclimation, a 60-day experimental study was conducted with four different types of treatments; namely, T1: Control, i.e. Basal feed without Probiotic supplements, T2: Basal feed with Aeromonas hydrophila, T3: Lactobacillus supplemented probiotic feed without Aeromonas hydrophila, and T4: Lactobacillus supplemented probiotic feed with A. hydrophila. After the experimental study, growth parameters were monitored through Weight gain, Specific growth rates, survival percentage, and haematological parameters including WBC, RBC, haemoglobin (Hb), and haematocrit (Hct) values of probiotics treated group (T3 and T4) were significantly (P<0.05) higher than control and T2 group. The Present study indicated that the positive effects of the L. acidophilus probiotic supplement diet improved the survival, growth, and Haematological performance in aquaculture.

Feeding global aquaculture.

The growth of animal aquaculture requires ever more feed. Yet, fish and crustacean farming is argued to be sustainable because wild fish use is low and has improved over time. Here, accounting for trimmings and by-products from wild fish in aquaculture feed, and using four different sources of industry-reported feed composition data, we find ratios of fish inputs to farmed outputs of 0.36 to 1.15-27 to 307% higher than a previous estimate of 0.28. Furthermore, a metric that incorporates wild fish mortality during capture and excludes unfed systems raises the wild fish mortality-to-farmed fish output ratio to 0.57 to 1.78. We also evaluate terrestrial ingredients in aquaculture feeds. Widely cited estimates of declines in wild fish use from 1997 to 2017 entailed a trade-off of more than fivefold increase in feed crops over the same period. Our assessment challenges the sustainability of fed aquaculture and its role in food security.

Real‐time estimation of olive flounder growth in indoor aquaculture using cameras combined with a grid

AbstractEstimating fish growth in real time has many benefits for indoor aquaculture farms, such as saving labor time and costs, reducing water pollution during feeding, improving feeding activity and determining when to harvest. Hence, this study proposed a visual‐information‐based method for measuring olive flounder (Paralichthys olivaceus) length, using accurate growth tracking for efficient aquaculture management. Using two cameras, an light‐emitting‐diode (LED) grid was placed at the bottom of the water tank to measure fish length. The pixels unit from the fish length in the captured image was converted to centimeters based on the relationship of a pre‐built dataset. A total of 180 lengths were calculated using images captured by the cameras. The average length of each fish acquired from the cameras was calculated separately, and Lagrange's interpolating polynomial algorithm was implemented to calculate the overall length of each fish. This method reduced the computational complexity, and results were obtained more rapidly and in a user‐friendly environment. The power model generated the length–weight relationship, which allowed us to estimate the body weight of each olive flounder based on the length. The proposed approach enabled us to calculate the length of olive flounders with a highly accurate R2 of 0.995.

Crassocephalum crepidioides as a sustainable protein supplement in Chocolatemahseer (Neolissochilus hexagonolepis) diets: Implications for growth,health, and economic viability in sustainable aquaculture

This study investigated the potential of Crassocephalum crepidioides, an abundant weed as a protein supplement in chocolate mahseer (Neolissochilus hexagonolepis) diets. The plant replaced a combination of fish meal and mustard oil cake at 0%, 25%, 50%, 75%, and 100% in experimental diets. A 12-week feeding trial was conducted to assess growth performance, survival, biomass yield, digestive enzyme activity, blood parameters, and economic viability. Results indicated that C. crepidioides can effectively replace up to 61.3% of the combined fish meal and mustard oil cake protein without negatively impacting fish health or growth, while reducing feed costs. Fish fed diets with 25% replacement showed improved weight gain (15.5±0.7 g) and biomass yield (6.05±0.25 kg/m³) compared to the control (14.6±0.8 g and 5.75±0.28 kg/m³, respectively). Survival rates were high across all treatments (94.0- 97.3%). Digestive enzyme activities and blood parameters remained within normal ranges for inclusion levels up to 75%. Economic analysis revealed potential cost savings of up to 15.5% when incorporating C. crepidioides into mahseer diets. This finding presents an opportunity to develop low-cost fish feed for resource-poor farmers in Meghalaya, effectively converting a local weed into a valuable aquaculture input, with broader implications for sustainable aquaculture practices globally.

Aquaculture growth and coastal tourism development in the context sustainable blue economy

AbstractThe primary objective of this research is to investigate the impact of increased aquaculture output on coastal tourism and blue growth in European Union developed countries (EU13) and European Union developing countries (EU14) from 1990 to 2023. Key findings were derived through the application of resilient least squares (RLS), two‐stage least squares (2SLS), and ordinary least squares (OLS) estimators, effectively addressing endogeneity concerns. The exact magnitudes of these results show that, in EU14 developed countries, the increase of aquaculture output seriously jeopardizes the sustainability of coastal tourism more so than in EU13 developing countries. In contrast, EU14 developed countries find that variables like as economic growth and institutional quality have a greater impact on improving coastal sustainable development than do EU13 countries. Moreover, the data shows that, in comparison to EU14 developed countries, the aquaculture sector in EU13 developing countries uses more fossil fuels than EU14 developed countries, which is the main driver of carbon dioxide emissions in coastal tourist areas. In light of these findings, the study recommends that policymakers give policies targeted at enhancing productivity and encouraging the environmentally friendly growth of aquaculture production top priority, particularly in the EU14 developed countries that have significant negative effects on the sustainable development of coastal tourism.

Enhancing Global Food Security through Sustainable Fisheries and Aquaculture: A Comprehensive Review

As the global population rises, addressing food security becomes more critical, particularly in developing regions struggling with hunger and malnutrition. Fisheries and aquaculture provide a vital solution by offering essential nutrition, employment, and economic benefits to millions worldwide. This study conducts an in-depth review of how capture fisheries and aquaculture contribute to global food security, emphasizing ten key areas: sustainable fisheries management, aquaculture growth, nutritional advantages, economic empowerment, climate adaptability, post-harvest loss reduction, policy and governance, technological advancements, biodiversity preservation, and global market access. The review evaluates the strength and consistency of evidence regarding the positive impact of these sectors on food security and poverty alleviation. The findings highlight the importance of cohesive policy and governance, technological improvements, and broader market access to fully leverage the role of fisheries and aquaculture in addressing global food challenges. Additionally, this review identifies research gaps that need to be addressed to maximize the sectors' potential for economic growth and environmental sustainability

Analysing Consequences of Aquaculture in Coastal Water Bodies of Ba Ria– Vung Tau, Vietnam on Sustainable Development Goals for Environmental Management

Aquaculture is vital for global food security and economic growth, particularly in coastal regions like Ba Ria – Vung Tau, Vietnam. This province has seen significant aquaculture growth, with production rising from 10,687 tons in 2010 to 20,486 tons in 2022. Key species farmed include brackish water shrimp, marine finfish, and mollusks, using methods such as cage culture, pond farming, and Integrated Multi-Trophic Aquaculture (IMTA). However, aquaculture poses environmental challenges, including conflicts over coastal space, waste management, and habitat degradation. Species like oysters and mussels help improve water quality and support balanced ecosystems, while marine finfish farming can cause nutrient overload and eutrophication. Sustainable practices like IMTA, waste management, and sustainable feed use are essential to mitigate these impacts. Aligning aquaculture with Sustainable Development Goals (SDGs), especially SDG 14 (Life Below Water), SDG 12 (Responsible Consumption and Production), and SDG 13 (Climate Action), is crucial for sustainable coastal management. This requires robust regulations, multi-stakeholder collaboration, and the integration of scientific research into policy. By ensuring aquaculture practices support SDGs, Ba Ria – Vung Tau can enhance environmental stewardship, economic resilience, and the sustainable coexistence of human activities with marine ecosystems.

Detection and Diversity of Tetracycline Resistant Bacteria in Fish Ponds of Rajshahi Region

The growth of aquaculture as a key food production industry, particularly in Bangladesh, has led to the increased use of various chemicals and drugs. This study focuses on the critical analysis of bacterial profiles in the waters of fish farming ponds in the Rajshahi district of Bangladesh, a necessary step for disease management and addressing the public health issues related to antibiotic-resistant bacteria. The research found a significant presence of bacteria in these waters, with viable bacterial counts fluctuating from 3.0×10² to 4.2×10³ CFU/ml at a Tetracycline concentration of 32 µg/ml, and 0.5×10² to 1.8×10³ CFU/ml at 64 µg/ml. Using 16S rRNA gene analysis, we discerned a dozen distinct bacterial species spanning six genera that demonstrate resistance to tetracycline. These include Enterobacter asburiae, Aeromonas sp., Acinetobacter sp., Bacillus sp., Bacillus cereus, Enterobacter cloacae, Acinetobacter gandensis, Escherichia coli, Shigella sp., Enterobacter hormaechei, Acinetobacter baumannii, and Bacillus altitudinis. The study underscores the critical need for preventive actions in fish farming to address these resistant bacteria and calls for comprehensive research to trace their origins and pathways of transmission. This research significantly contributes to the understanding of antibiotic resistance in aquatic ecosystems and its broader implications for public health. J. Bio-Sci. 32(2): 23-30, 2024

Assessing the direct and indirect effects of bigheaded carp (Hypophthalmichthys spp.) on freshwater food webs: A meta‐analysis

Abstract The rapid growth of aquaculture over the last century has led to the widespread introduction of aquatic species to freshwater environments. Bighead carp (Cyprinidae: Hypophthalmichthys nobilis) and silver carp (Cyprinidae: Hypophthalmichthys molitrix), collectively referred to as bigheaded carp, are among the top finfishes produced in aquaculture. These filter feeders possess feeding structures that allow them to efficiently remove plankton and other particles from the water. Unfortunately, when introduced into the wild and outside their historical range, their feeding traits generally result in the exploitation and suppression of phytoplankton and zooplankton, reducing food resources for native invertebrates and vertebrates. We conducted a meta‐analysis of published experiments to examine how bigheaded carp directly and indirectly affect organisms in aquatic food webs to better understand their ecological role within ecosystems. Specifically, we addressed the following questions: (1) What is the overall magnitude and direction of bigheaded carp effects on different aquatic organisms? (2) Do bigheaded carp affect organisms in planktonic and benthic habitats? (3) Are effects similar between bighead carp and silver carp? (4) Are effects consistent among experimental arenas (i.e., mesocosm, ponds)? We detected direct and indirect effects of bigheaded carp across multiple trophic levels. Large zooplankton often exhibited the strongest negative effects, with taxa‐specific differences between carp species. The suppression of zooplankton cascaded down to primary producers, resulting in an increase in phytoplankton (i.e., indirect effect). However, we observed no compensatory increases in rotifers when large zooplankton were reduced. Growth rates of planktivorous native fishes were the slowest when stocked with bigheaded carp. Our results further indicated that egested waste from bigheaded carp appeared to subsidise (i.e., direct effect) some benthic invertebrates such as Chironomidae midges. Effects of carp on zooplankton were generally similar between mesocosms and ponds. Invasive bigheaded carp greatly restructure their surrounding food web, both positively and negatively, through a complex suite of direct and indirect effects. These changes manifested across multiple trophic levels and differing habitats. Our analysis provides a more complete understanding of how these invasive carps change their surroundings by exploiting food resources and transferring materials from planktonic to benthic habitats. Taken together, the suite of direct and indirect effects shows how an invasive species can create imbalances within aquatic ecosystems, often to the detriment of native taxa. Bigheaded carp are invasive in many countries across the globe because of their popularity in aquaculture. Our findings reaffirm the threat these planktivores pose to native freshwater organisms.

Sharp decline in surface water resources for agriculture and fisheries in the Lower Mekong Basin over 2000-2020

Water resources play a crucial role in the global water cycle and are affected by human activities and climate change. However, the impacts of hydropower infrastructures on the surface water extent and volume cycle are not well known. We used a multi-satellite approach to quantify the surface water storage variations over the 2000–2020 period and relate these variations to climate-induced and anthropogenic factors over the whole basin. Our results highlight that dam operations have strongly modified the water regime of the Mekong River, exhibiting a 55 % decrease in the seasonal cycle amplitude of inundation extent (from 3178 km2 to 1414 km2) and a 70 % decrease in surface water volume (from 1109 km3 to 327 km3) over 2000–2020. In the floodplains of the Lower Mekong Basin, where rice is cultivated, there has been a decline in water residence time by 30 to 50 days. The recent commissioning of big dams (2010 and 2014) has allowed us to choose 2015 as a turning point year. Results show a trend inversion in rice production, from a rise of 40 % between 2000 and 2014 to a decline of 10 % between 2015 and 2020, and a strong reduction in aquaculture growth, from +730 % between 2000 and 2014, to +53 % between 2015 and 2020. All these results show the negative impact of dams on the Mekong basin, causing a 70 % decline in surface water volumes, with major repercussions for agriculture and fisheries over the period 2000–2020. Therefore, new future projects such as the Funan Techo canal in Cambodia, scheduled to start construction at the end of 2024, will particularly affect 1300 km2 of floodplains in the lower Mekong basin, with a reduction in the amount of water received, and other areas will be subjected to flooding. The human, material and economic damage could be catastrophic.

Study on recirculating aquaculture system (RAS) in organic fish production

Abstract The growth of conventional aquaculture has created environmental issues due to excessive feeding, low dissolved oxygen level etc into the water body. Organic aquaculture is a recent development as a solution to these issues. It is a clean alternative to reduce pollution and to produce safer consumable food. In the past few decades, recirculating aquaculture systems (RAS) were introduced to maintain pond water quality through lesser water exchange, by focusing on water reuse after treatment. In this study, the technical viability of RAS was analyzed for introduction in organic aquaculture systems. Indian major carps (IMCs) were cultured through conventional methods in the three tanks of conventional system, while the same species was grown organically in another three tanks in organic system. The stocking density and physical conditions were kept same for both cultured systems. The RAS consisted of fish culture tank with an average volume of each tank was 165 m3, a screen filter, foam fractionator and trickling filter. The various water quality parameters, i.e., solid size distribution in water, and removal efficiencies in biological treatment of both systems were compared. The present study, particle size distribution of solids in water body was measured by filtration, followed by weighing of dry residue solids. Pore sizes of 1000μ, 100μ, 20μ and 3μ were employed for filtration. For organic tanks, a majority of solids are of size between 1 mm and 100 μm. The larger sized particles (> 30 μm) constitute nearly 70 % of the solids and the trait differs from the generalized conclusions of that a major part of sediments will be of sizes less than 20 μm. For the conventional tanks, majority of solids are of size between 3 mm and 20 μm and TAN shows higher removal efficiencies for effluents from organic system rather than conventional system. The results showed that organic aquaculture causes lesser pollution load per weight of fish. The particle size distribution of organic water was better compatible to screening and sedimentation than conventional water. Also the filtration efficiencies in nitrifying trickling filters of both water bodies were comparable, with that of organic water slightly on the higher side. Thus recirculating water treatment systems are introduced in organic aquaculture.

Effects of dietary fish oil replacement with rice bran oil on growth performance, serum biochemical index, antioxidant capacity, lipid metabolism and inflammatory response of large yellow croaker (Larimichthys crocea) juveniles

Fish oil (FO) replacement has become a top priority with the increasing growth of aquaculture and the decline of FO production. Dietary rice bran oil (RBO) has been marked with good application prospects and development potential in humans and terrestrial animals. Hence, this study was geared towards ascertaining the effects of replacing dietary FO with RBO in fish feeds. In this study, a 74-day feeding trial was conducted with large yellow croaker (Larimichthys crocea) juveniles to ascertain the effects of dietary FO replaced by different levels (0%, 25%, 50%, 75% and 100%) of RBO. Each diet was randomly fed to triplicate groups of large yellow croaker juveniles (120 fish per group) with an initial mean body weight of 13.02 ± 0.02 g. Fish fed with dietary RBO 25% showed significantly higher final body weight, weight gain rate, specific growth rate, and feed intake compared to other treatments. Also, fish fed diets with RBO showed significantly higher antioxidant capacity compared to the control. Interestingly, fish fed with RBO 25% diet showed a significantly improved serum lipid profile when compared to the control. Moreover, the hepatic mRNA expression of sterol regulatory element-binding protein-1 (srebp-1), and fatty acid synthase (fas) was significantly upregulated in RBO 25% replacement, while peroxisome proliferator-activated receptor α (pparα), was significantly suppressed in fish fed RBO 100% compared to the control. Furthermore, fish fed RBO 100% had significantly increased Interleukin-1β (il-1β), Tumour necrosis factor-α (tnf-α), and Interferon-γ (ifn-γ), and significantly decreased transcript levels of Interleukin-10 (il-10). Therefore, the results of the present study showed that RBO could promote the performance of large yellow croaker juveniles, by improving the growth indexes, serum biochemical properties, antioxidant capacity, and alleviating liver inflammation.

Molecular identification of Mymarothecium viatorum and Anacanthorus penilabiatus in extensive native fish farming systems of the Peruvian Amazon

Piaractus brachypomus (Pacú) is the main native fish species cultivated in Peru and holds great potential for growth in aquaculture from the Peruvian Amazon. Between October 2021 and January 2022 in two fish producing farms in the Amazon region of San Martín in Peru, P. brachypomus individuals were examined for parasite evaluation. A total of 6366 monogeneans were isolated from the gills of 30 fish, revealing a prevalence of 100%, with an abundance and mean intensity of 212 parasites per fish. Monogeneans were morphologically identified as Mymarothecium viatorum and Anacanthorus penilabiatus. The genetic divergence in the 28S rDNA gene found among A. penilabiatus sequences was 0.1% and among Anacanthorus spp. it ranged from 0.9% to 7.5%. The genetic divergence found among the M. viatorum sequences was 0.3%. These finding represents the first molecular data of M. viatorum and A. penilabiatus in Peru using the 28S rDNA gene of these monogeneans. The new sequences obtained will contribute to future studies on the phylogenetic relationships among dactylogyrids. However, further research with a broader range of host-parasite samples and additional genetic markers is needed to clarify these relationships and provide stronger support for the phylogenetic positions.

Farmed fish welfare research status in Latin America: A review.

Latin America (LATAM) plays an important role in the world's production of aquatic animals and is the second most productive region in the world. Chile, Ecuador, Brazil, Mexico, Colombia, and Perú contribute 87% of LATAM aquaculture production. The fish welfare in aquaculture is of increasing public concern globally, and LATAM is no exception, growing in importance for fish farmers, authorities, and scientists. Although the topic is somewhat controversial, the welfare status of farmed fish has direct implications for their production and the sustainability of the industry. Therefore, this study analyses scientific papers on animal welfare in farmed fish, from the six countries in LATAM with the highest aquaculture production. The main objectives were to quantify the number of papers published between 2000 and 2023 on fish welfare by using scientific databases. A total of 285 papers were found for the period analysed. The country with the largest number of publications was Brazil (75.79%), followed by Chile (13.33%), Mexico (7.02%), Peru (1.75%), Ecuador, and Colombia (1.05%). Nile tilapia was the most studied species, appearing in 30.18% of the publications, with most of the studies mainly dealing with nutrition (32.28%). The growth of aquaculture is leading to joint efforts to generate knowledge on welfare issues, especially in poorly studied species with high production, to create policies that help minimize welfare risks. Given this, the insights generated by this review could be a useful addition to approaches investigating the trends and concepts of fish welfare in LATAM.