Aquaculture Research最新文献

Significant growth heterogeneity is prevalent in farmed Japanese eels (Anguilla japonica), whereas its underlying causes remain poorly understood. The study investigated the metabolic, digestive, and behavioral phenotypic differences between fast- and slow-growing A. japonica. A total of 100 elvers (22.88 ± 1.11 g) were randomly allocated into four net cages (25 individuals per cage). After 8 weeks of rearing, the three heaviest and three lightest individuals from each cage were selected and designated as fast-growing eel (FGE) and slow-growing eel (SGE), respectively. Plasma metabolic profiling revealed that SGE showed significantly lower levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and lactate compared to FGE, while aspartate aminotransferase (AST) was higher (p < 0.05). Moreover, oxygen consumption rate (OR) and ammonia excretion rate (AR) in SGE were significantly higher than FGE. Significant differences in digestive and metabolic enzyme activities were observed, with SGE displaying lower amylase, trypsin, Na⁺-K⁺-ATPase, and ATPase levels than FGE (p < 0.05). In behavioral phenotypes, SGE exhibited a longer latency time, along with reduced total feed intake and amount of feces than FGE, while no significant differences in relative feed intake or relative amount of feces. Additionally, compared to FGE, the expression levels of neuropeptide Y (npy) and ghrelin were significantly downregulated in SGE, whereas corticotropin-releasing hormone (crh) mRNA upregulated (p < 0.05). Multivariate analysis identified that AST and crh may serve as primary discriminators for SGE classification. In conclusion, the differences in feeding behavior, metabolic level, and digestive capacity were related to growth disparity between individual eels. These findings advanced our mechanistic understanding of growth variation in A. japonica and provided valuable insights for promoting uniform growth.

Bullfrogs (Aquarana catesbeiana) are an important aquaculture species worldwide. However, diseases have caused significant losses to the bullfrog industry. Given the crucial role of the intestinal microbiota (IM) in bullfrog growth, nutrition, immunity, and health, as well as the potential of probiotics and Chinese herbal medicine (CHM) to regulate intestinal health, this review systematically examines common bullfrog diseases and IM structure. This includes pathogenic bacterial species and their effects, the composition of probiotics and opportunistic pathogens, and the factors influencing the IM structure. Additionally, this review explored the effects of probiotics and CHM on the IM of bullfrogs. Using probiotics, CHM, and other strategies to improve the structure of IM can effectively prevent and control opportunistic infections and promote the sustainable development of bullfrog aquaculture. This review will be valuable for understanding the role of IM in promoting bullfrog growth and preventing disease outbreaks. This highlights the importance of regulating IM during the culture process to prevent outbreaks of bullfrog diseases.

The growth of the human population requires the establishment of additional food-producing sectors to meet the increasing demand for animal protein sources. In this context, integrated fish farming presents a viable option for enhancing yield diversification with minimal investment costs. The objective of this study was to evaluate the productivity and profitability of Nile tilapia (O. niloticus) and Swiss chard (Beta vulgaris L. var. cicla). The experiment was conducted at Hawassa University’s Centre for Aquaculture Research and Education (CARE) from February 2023 to May 2023. It involved stocking 150 fingerlings of Nile tilapia (O. niloticus) with an average weight of 9.8 g in 80 m² ponds, alongside the cultivation of Swiss chard in 15 plots measuring 2 m × 2 m, arranged in a randomized complete block design (RCBD). Swiss chard was grown under five different treatments: compost, chemical fertilizer, Black Soldier Fly larvae Frass Fertilizer (BSFFF), tap water as a control, and pond water. Data on fish and vegetable growth parameters and yields were collected and analyzed using SAS software (version 13) at a 95% confidence interval. Results indicated that O. niloticus attained a higher final body weight of 98.6 g. Swiss chard treated with fish pond water showed significantly higher growth improvements in leaf length, width, and number (p  < 0.05) compared to all treatments except BSFFF. Yields at harvest from compost, chemical fertilizer, BSFFF, tap water, and pond water were 49, 52.4, 53.5, 30.6, and 58.7 kg, respectively, with differences among treatments that were not significant, except for the control plots yielding 30.6 kg, which was significantly lower than the others (p  < 0.5). A cost–benefit analysis revealed that Swiss chard treated with pond water attained higher profitability than the other treatments. Based on the findings of the present study, it is recommended that fish-vegetable integration especially that of Nile tilapia and Swiss chard enhances yield and economic benefits.

Chitosan is a biopolymer popularly used as a functional feed additive. There are various sources of chitosan, including black soldier fly larvae (BSFL). This study aimed to evaluate the potential of BSFL-derived chitosan in the modulation of intestinal microbiota in Macrobrachium rosenbergii. The prawns were randomly distributed into four groups, and the diets supplemented with chitosan at levels viz., 0 g/kg (control [C]), 2 g/kg shrimp shell chitosan (T1), 2 g/kg BSFL chitosan (T2), and 4 g/kg BSFL chitosan (T3) were fed for 90 days. In terms of growth performance, the T3 group exhibited significantly the highest weight gain (WG) (%) (470.10 ± 24.90), and upregulation of antioxidant immune genes sod and cat, compared to the other treatment groups. The 16S rRNA amplicon sequencing was performed on the prawn gut samples. The T3 had a significantly higher abundance of phyla Firmicutes (33%), Bacteroidota (2.2%), genus Chitinibacter (11.3%), and Clostridium (2.5%) compared to the control. The T3 also had higher indices of alpha diversity compared to other groups. The T3–control comparison exhibited the highest dissimilarity coefficient (0.118). The unweighted pair-group method with arithmetic mean (UPGMA) results indicated clustering among treatment groups. The analysis of similarity (Anosim), multiresponse permutation procedure (MRPP), ADONIS, and metagenomeSeq analyses confirmed a significant community difference (phylum Bacteroidota, genus Clostridium, and Chitinibacter) between the control and T3 groups. The linear discriminant analysis effect size (LEfSe) revealed potential biomarkers, and T3 exhibited the highest linear discriminant analysis (LDA) scores for order: Burkholderiales, family: Chitinibacteraceae, genus: Chitinibacter, and order: Clostridiales, family: Clostridiaceae, genus: Clostridium. The pathways related to biosynthesis, metabolism, signaling, and cellular processes were higher in T3, thus contributing to better growth. This study suggested that BSFL chitosan at 4 g/kg diet modulates and enhances beneficial bacteria in the gut of M. rosenbergii and promotes growth and immunity.

Aquaculture seeks sustainable methods to improve fish growth and muscle development. This study evaluated the effects of adding white button mushroom powder (WBMP) to the diet on growth performance, feed efficiency, muscle growth, and expression of muscle-growth-related genes in fingerlings Nile tilapia (Oreochromis niloticus). Over 56 days, 240 fish were fed either a basal additive-free control diet (0%) or diets supplemented with 0.5%, 1%, or 2% WBMP (Agaricus bisporus). Key measures included weight gain (WG), specific growth rate (SGR), feed intake (FI), protein efficiency, and net protein utilization. Muscle development was examined histologically, and gene expression of myogenic regulators MyoD, Myogenin, and the growth inhibitor Myostatin was quantified. Fish receiving 1% mushroom powder showed the greatest improvements in growth and feed efficiency, accompanied by increased MyoD and Myogenin expression, indicating enhanced muscle hypertrophy. Hematological and biochemical parameters were unchanged across treatments, indicating no adverse health effects. The optimal dietary inclusion was estimated at 1.23% mushroom powder per kilogram of feed. These findings suggest that WBMP is a promising functional feed additive for Nile tilapia, improving growth and muscle quality through multiple physiological pathways. This study offers a new understanding of how dietary mushrooms support compensatory growth in aquaculture species.

Astaxanthin, a potent keto-carotenoid, has emerged as a critical bioactive compound in aquaculture and human health. This review synthesizes current knowledge on astaxanthin’s multifunctional roles, spanning pigmentation enhancement, growth promotion, stress resilience, and disease resistance in farmed aquatic species. In aquaculture, astaxanthin addresses a key industry challenge: meeting consumer demand for vibrant, nutrient-rich seafood while optimizing animal health. Unlike synthetic alternatives, natural astaxanthin derived primarily from Haematococcus pluvialis microalgae or Xanthophyllomyces dendrorhous yeast acts as a superior antioxidant, with efficacy 10–100 times greater than α-tocopherol. It enhances shrimp and salmonid physiology by improving immune responses, reproductive performance, and oxidative stress management, while its esterified forms boost bioavailability. For humans, astaxanthin’s unique ability to cross the blood–brain and blood–retina barriers underpins its neuroprotective, anti-inflammatory, and cardio-metabolic benefits, supported by clinical trials. Advances in sustainable production, including algal bioreactors and genetic engineering, are overcoming scalability limitations. However, gaps persist in understanding molecular mechanisms, optimal dosing, and long-term effects. Future research should prioritize pharmacokinetic studies, industrial applications, and translational health benefits. By bridging aquaculture innovation and biomedical potential, astaxanthin exemplifies a convergence of ecological and therapeutic value, positioning it as a transformative agent in global food systems and preventive medicine.

The current study is a new approach for investigating the ameliorative effects of chia seeds powder (CSP) (Salvia hispanica) against haemato-biochemical dysfunction, oxidative stress, and DNA damage induced by zinc oxide nanoparticles (ZnONPs) in Oreochromis niloticus. Four fish groups were allocated in triplicates as follows: group I-control, group II-treated with 10 g/kg diet CSP, group III-exposed to 1/20 LC₅₀ of ZnONPs, and group IV-exposed to 1/20 LC₅₀ of ZnONPs + 10 g CSP/kg diet for 30 days. Blood, liver, and kidney tissue samples were collected at the end of the experiment for haemato-biochemical, oxidative stress biomarkers, and DNA damage evaluations. Results revealed that CSP administration significantly ameliorated the ZnONPs toxic effect. Where, CSP effectively increased WBCs, and serum total proteins, albumin, globulin, and immune parameters (IgG, IGM, and lysozyme [LYZ] activity), which were decreased after exposure to ZnONPs toxicity. In addition to the prominent ability of CSP to decrease the elevated levels of stress indicators (glucose and cortisol), liver enzymes (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), kidney products (creatinine and urea), catalase (CAT), superoxide dismutase (SOD), and hepato–renal lipid peroxidation (LPO) of Nile tilapia exposed to ZnONPs. Furthermore, CSP sustained the activity of the reduced glutathione (GSH), total antioxidant capacity (TAC), and WBCs, Hb, and Ht content were significantly declined in ZnONPs-exposed O. niloticus compared to the control group. Meanwhile, administration of 10 g CSP/kg diet restored the hemato-biochemical profile and reduced oxidative damage induced by ZnONPs toxicity as the WBCs and hepatic DNA damage were significantly increased in exposed fish. The study suggested that CSP treatment has hepato-renal protective functions and antioxidative effect against ZnONPs toxicity in Nile tilapia.

Corn production in the US results in a variety of products, including ethanol and the recycling of coproducts into animal feed. Corn fermented protein (CFP) is a high-protein, low-fiber improved coproduct of the ethanol industry that is rich in lysine and methionine and doesn’t contain antinutritional factors. Because of these attributes, CFP is a potential candidate to replace soybean meal (SBM) whilst improving animal growth and health. Accordingly, the present work assesses the effects of CFP on channel catfish growth, whole-body composition, overall health, and resistance to major disease-causing bacteria. Six experimental diets were formulated to include CFP at 0%, 5%, 10%, 15%, 20%, and 30%. After feed preparation, 20 channel catfish fingerlings (2.56 ± 0.06 g) were randomly assigned to six replicate aquaria per diet. During the 70-day experiment, catfish were weighed biweekly, and the feed ration was calculated as a percentage of the aquarium biomass and increased by 10% the following week. At termination, fish were group-weighed, enumerated, then sampled for whole-body proximate, serum lysozyme activity and biochemistry analyses. Subsequently, another set of catfish (5.29 ± 0.19 g) were acclimated to the diets for 42 days. Afterward, fish were challenged by immersion with Flavobacterium covae (1.00 × 10⁶ CFU mL⁻¹), virulent Aeromonas hydrophila (3.55 × 10⁷ CFU mL⁻¹), and Edwardsiella ictaluri (1.60 × 10⁵ CFU mL⁻¹). Results of the present work suggest that CFP can be successfully used at 30% of channel catfish diets. Fish growth, survival, protein retention, whole-body proximate composition, serum lysozyme activity, or biochemistry were similar regardless of the CFP inclusion level (p > 0.05). Additionally, CFP inclusion does not seem to confer protection against F. covae or virulent A. hydrophila infections but seems to change catfish survival postinfection with E. ictaluri. CFP can be successfully used as an ingredient in channel catfish diets, but the potential to protect the fish against bacterial infections needs further investigation.

Florida bass, Micropterus salmoides, an economically important sport fish species, has great potential for indoor recirculation aquaculture systems (RAS), but knowledge about optimal dietary requirements during the early life history stages remains unresolved. Thus, the objective of this study was to determine a first-feeding protocol for Florida bass indoor RAS culture. Four dietary treatments were tested: treatment 1 received rotifers with enriched Artemia, treatment 2 received rotifers with nonenriched Artemia, treatment 3 received only enriched Artemia, while treatment 4 received nonenriched Artemia. At 5 days posthatch (DPH), all treatments received a microdiet. Fish were sampled in regular intervals for total length (TL), body area (BA), myotome height (MH), jaw length (JL), eye diameter (ED), oil droplet area (ODA), and yolk area (YA). Condition index (CI), yolk utilization efficiency (YUE), and yolk utilization rate (YUR) were calculated. Wet weight, tank biomass, and survival were also recorded at 25 DPH. Results showed that Artemia enrichment did not influence any of the morphometric traits. Adding rotifers or enriched artemia did not significantly impact weight, final biomass, or survival at 25 DPH for Florida bass. Larvae fed rotifers exhibited a significant increase in morphometric development (TL, BA, MH, JL, ED, and CI) and were more efficient and faster at converting yolk reserves to body size. We conclude that a dietary regimen including rotifers allows Florida bass larvae to transition to exogenous energy sources faster and increase development. The present study improves understanding of black bass dietary requirements during critical early life history stages to increase hatchery efficiency.

A two-part study was conducted to evaluate the impact of exogenous protease supplementation on the performance of Pacific white shrimp (Penaeus vannamei): a controlled in vivo feeding trial and a systematic review with meta-analysis. In the feeding trial, a 90-day experiment was conducted using diets supplemented with protease, administered to shrimp stocked at 90/m². The experimental design applied was completely randomized, with treatments organized in increasing doses of exogenous protease (0, 125, 250, and 500 g/t) supplemented in “on top” mode in commercial feed with 35% protein, extruded, and with pellets of 1.6 mm in diameter. The results showed a significant increase in performance with the use of exogenous protease in the diet of shrimp grown under a density of 90 shrimp/m². Live weight had a linear increasing effect (p  < 0.001), as did feed intake (p  < 0.001), weight gain (p  < 0.001), and survival (p  < 0.001), while feed conversion ratio (FCR) had a quadratic effect (p = 0.005). The supplementation of exogenous protease showed to have an influence on the control diet, resulting in satisfactory increments when analyzing weight gain indices. The study demonstrates positive effects in the addition of exogenous protease, with significant effects on the performance of shrimp. The meta-analysis included 7,080 shrimps from peer-reviewed studies comparing protease-supplemented and control diets. Three outcome measures were analyzed, daily body weight gain (dBWG), FCR, and survival rate. The database was composed of eight comparisons in weight gain (dBWG, g/shrimp/day), 8 comparisons in feed conversion rate (FCR, g/g), and eight comparisons in survival (survival %). Meta-analysis revealed evidence in the literature that P. vannamei shrimp fed diets supplemented with exogenous protease enzyme or not do not vary in terms of survival rate (p = 0.08437). Feed conversion in P. vannamei shrimp showed significant evidence that P. vannamei shrimp fed diets supplemented with exogenous protease enzyme. A dosage of 175 mg/kg was identified as optimal across the analyzed studies without significant changes in animal survival.