Aquaculture Nutrition最新文献

Reproductive maturation remains a central bottleneck in crustacean aquaculture, as ovarian development dictates broodstock quality, fecundity, and larval viability. This review synthesizes current knowledge on the physiological regulation of ovarian maturation in decapod crustaceans, emphasizing the interplay of hormones, nutrients, and environmental factors. Eyestalk-derived neuropeptides of the crustacean hyperglycemic hormone (CHH) family, together with molt-inhibiting hormone (MIH), vitellogenesis-inhibiting hormone (VIH), methyl farnesoate (MF), and ecdysteroids, constitute the core hormonal regulators, with CHH and MF promoting vitellogenesis while VIH exerts inhibitory control. Among nutritional drivers, proteins, amino acids (notably arginine), long-chain polyunsaturated fatty acids (LC-PUFAs), cholesterol, and carotenoids exert the most pronounced effects on vitellogenesis, oocyte maturation, and larval quality, with their regulatory roles frequently mediated through endocrine pathways such as mTOR and steroidogenesis. Evidence across species indicates that optimal ovarian growth is generally achieved at dietary protein levels of 30%–35%, lipid levels of 8%–12%, and specific amino acid concentrations including 2.5%–4.5% arginine, 0.6%–1.0% taurine, and 1.5%–1.7% threonine. Favorable temperature and photoperiod can regulate ovarian development better and lead to higher spawning rates and reproductive effects compared to salinity. Finally, the economic feasibility of nutritional interventions is evaluated, highlighting that while cholesterol and krill oil are biologically effective, their high cost necessitates strategic use alongside sustainable alternatives such as phytosterols, marine by-products, and plant- or insect-based proteins. By consolidating hormonal, nutritional, and environmental perspectives, this review outlines regulatory mechanisms of ovarian development while identifying practical strategies to improve broodstock management and reproductive efficiency in crustacean aquaculture.

Ellagic acid (EA), in pure form or extracted from pomegranate (Punica granatum) peel (PP), is a bioactive polyphenol that provides strong anti-inflammatory and antioxidant effects in cultured fish. To investigate the benefit and any adverse effects of PP as a source of EA, and pure EA by assessing growth parameters, digestive enzymes, antioxidant, and immune factors when supplied to 450 juvenile Oreochromis niloticus (10.4 ± 0.9 g) over 60 days. Feeding treatments used a standard feed with EA included at three concentrations (i.e., 0.1, 0.15, and 0.2 g kg⁻¹) and PP at three concentrations (i.e., 10, 15, and 20 g kg⁻¹) and in combination with similar doses (i.e., EP 1 = 50 mg + 5 g kg⁻¹, EP 1.5 = 75 mg + 7.5 g kg⁻¹, and EP 2 = 100 mg + 10 g kg⁻¹ to keep the EA content around 0.1, 0.15, 0.2 g kg⁻¹, respectively) as well as a control without inclusion. The final weight (FW) of the fish was significantly increased in most treatments compared to the control group (p < 0.05). White blood cell (WBC) counts increased in higher dose treatments for both EA and EP (i.e., EA 0.2 g, EP 1.5, and EP 2). Antioxidant and key digestive enzyme (protease, lipase, and α-amylase) activities were generally elevated, with most treatments showing significant (p < 0.05) increases in the transcription of glutathione genes or activity of superoxide dismutase (SOD), catalase (CAT), and a decrease in the malondialdehyde (MDA). Immune responses showed significant increases in immunoglobulin M (IgM), lysozyme, and respiratory burst activity (RBA), and the expression of immune genes in several treatments. Notably, EA at 0.2 g and EP 2 elicited a stronger response than the other dosages for these parameters in Nile tilapia. These findings suggest that dietary supplementation with EA, PP, or their combination enhances growth performance, immune responses, and antioxidant capacity in O. niloticus, with the EA 0.2 g and EP 2 treatments showing the most pronounced effects.

Carbohydrates in aquaculture feeds can induce metabolic disturbance when exceeding fish utilization capacity, leading to lipid accumulation and insulin resistance. Bitter melon (BM; Momordica charantia), rich in saponins, flavonoids, and polysaccharides, shows potential as a functional feed additive for glycemic control and lipid metabolism modulation. This investigation systematically assessed the effects of BM powder (BMP) supplementation (at 0.5%, 1%, and 1.5%) in high-starch (HG) diets for Cyprinus carpio. Compared to the HG group, BMP supplementation significantly reduced serum glucose (GLU) and triglycerides (TGs), while elevating total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C). The BMP group exhibited reduced malondialdehyde (MDA), enhanced antioxidation ability, and mitigated hepatopancreatic and intestinal histopathological damage from carbohydrate overload. Meanwhile, BMP restored muscle C20:3n−6 and C22:6n−3 (DHA) levels decreased by HG diets. Notably, 1.5% BMP decreased hepatopancreatic and muscular glycogen/lipid deposition, induced by a high-carbohydrate diet. Gene expression analysis revealed BMP upregulated glycolysis-related genes (glucokinase [gk], pyruvate kinase [pk], and pfk) across tissues (hepatopancreas, muscle, intestine, and adipose tissue), while suppressing glycogen synthesis (gys) and gluconeogenesis (g6pase) genes. Besides, lipid biosynthesis genes were downregulated, corroborating reduced ectopic lipid storage. Taken together, these findings demonstrate that BMP supplementation significantly improves glycemic control, lipid metabolism, and antioxidant capacity in common carp. This suggests that BMP could serve as a natural, sustainable aquafeed additive to counter metabolic syndrome in intensively farmed fish.

Host-derived probiotics offer sustainable alternatives to the commercial nonaquatic formulations due to superior compatibility with the gastrointestinal environment of aquatic species. This study integrated: (i) isolation, identification (via 16S rRNA sequencing), and in vitro potentiality (pH and bile tolerance) of gut-derived bacteria from wild M. rosenbergii, and (ii) an in vivo 120-day aquarium trial to evaluate performance of these laboratory-isolated probiotics (T1) compared to a commercial probiotic formulation (T2), and a control group fed with no probiotics (T0). Nine bacterial isolates were identified, including Bacillus cereus, Enterococcus faecium, Glutamicibacter mysorens, and Staphylococcus succinus, which exhibited strong acid and bile tolerance. In vivo, probiotic treatments improved water quality by reducing ammonia and stabilizing pH, ammonia was significantly lower in T1 (0.28 ± 0.03 mg/L) than in T0 (0.36 ± 0.06 mg/L; p < 0.05). Growth performance was enhanced with probiotics: final average weights reached 3.92 ± 0.08 g in T1, 3.17 ± 0.06 g in T2, and 2.31 ± 0.13 g in T0. Specific growth rate (SGR) was significantly higher in T1 (2.87% ± 0.03%) compared to T0 (2.36% ± 0.05%). Feed conversion ratio (FCR) was lowest in T1 (0.32 ± 0.09) and highest in T0 (1.13 ± 0.14), while feed conversion efficiency (FCE) was highest in T1 (3.15 ± 0.50). Overall, laboratory-isolated/host-derived probiotics outperformed the commercial formulations by simultaneously enhancing growth, feed utilization, and water quality, emphasizing their usefulness as a species-specific, sustainable alternative for freshwater prawn aquaculture.

The present study determined the apparent digestibility coefficients (ADCs) of dry matter, nutrients, and energy in selected seven animal protein ingredients, including Peruvian fish meal (PFM), native fish meal (NFM), Antarctic krill meal (AKM), native shrimp meal (NSM), poultry by-product meal (PBPM), meat and bone meal (MBM), and hydrolyzed feather meal (HFM) for coho salmon (Oncorhynchus kisutch) post-smolts (initial body weight: 212.73 ± 5.15 g). Using yttrium oxide (Y₂O₃, 0.5 g/kg) as an inert marker, a reference diet was formulated to contain ~440 g/kg of crude protein and 200 g/kg of crude lipid, whereas the test diets were composed of the reference diet and one of the test ingredients at a ratio of 70:30. The dry matter ADCs of the test animal protein ingredients ranged from 65.14% to 83.77%. The ADC of energy followed a similar trend to that of dry matter (69.03%–87.52%). The crude protein and lipid in all the test ingredients were well digested by the post-smolts with ADCs ranging from 74.12% to 91.67% and 75.44% to 92.38%, respectively. The MBM and HFM had significantly (p < 0.05) lower amino acid ADCs than other animal protein ingredients, resulting in lower levels of protein digestion in these two terrestrial animal ingredients. The ADCs of phosphorus varied greatly among the animal protein ingredients, with the highest in PBPM (70.52%) and the significantly (p < 0.05) lowest in MBM (37.31%). These ADCs data suggest that PFM, NFM, AKM, NSM, and PBPM can be prioritized as high-quality protein sources and provide more accurate information for the nutrient and energy utilization of coho salmon.

This study evaluated the digestibility of defatted black soldier fly larvae (BSFL, Hermetia illucens) meals as alternative protein sources to partially replace fish meal (FM) in blue shrimp (Penaeus stylirostris) diets. It also examined the relationship between in vivo and in vitro digestibility methods to support the development of a reliable in vitro approach. Two BSFL-based mixes were tested: one with a higher chitin content (H70), and the other with a lower chitin content and also presenting a more balanced essential amino acid profile (M70). Each replaced 60% of FM in experimental diets (H20 and M20, respectively) and were compared to a control diet containing no BSFL meal. Apparent digestibility coefficients (ADCs) were measured in vivo using chromium oxide (Cr₂O₃; 1%) as an inert marker. In vitro digestibility was assessed using the pH-stat method with shrimp hepatopancreas enzyme extracts. In vivo results showed that the M20 feed had significantly higher digestibility than the control (p <0.05), while no significant difference in protein ADC was observed among diets. In vitro results indicated that the H20 feed had lower digestibility than the control (p <0.05). The ranking of protein digestibility (Control ≥ M20 ≥ H20) was consistent between both methods. A satisfactory correlation was found between in vivo and in vitro protein digestibility (R² = 0.691), which improved substantially after adjusting the in vitro assay temperature to match in vivo conditions (R² = 0.864). These findings suggest that the pH-stat method is a promising tool for preliminary assessment of ingredient digestibility, more precisely protein digestibility, in shrimp diets. Moreover, industrial BSFL meal appears to be a viable protein source for replacing upto 60% of FM in shrimp feed formulations without compromising shrimp survival or digestibility.

This study aimed to determine the effect of dual-strains probiotic (DSP) consisting of Lactobacillus casei and Bacillus subtilis on bacterial metagenomic profile, gut physiology, and digestive enzyme levels of African catfish (Clarias gariepinus) infected by Aeromonas hydrophila. The ratio between L. casei and B. subtilis was 1:1 each with a density of 10⁸ CFU/mL. Catfish (n = 8 fish per tank, three replicates per treatment) were fed diets supplemented with 0%, 5%, 10%, or 15% DSP for 42 days. On the 35th day, selected groups were intraperitoneally challenged with A. hydrophila at a dose of 0.1 mL × 10⁸ CFU/mL. The observed parameters included bacterial counts and microbial profile in the gastrointestinal tract (analyzed using next-generation sequencing [NGS]), gut physiology, and digestive enzyme levels (amylase, lipase, and protease). The results showed that DSP supplementation increased both the abundance and diversity of gastrointestinal microbes, elevated digestive enzyme levels, and enhanced the number of goblet cells in the intestinal lining. The dominant microbial phyla observed in the control group were Fusobacteria and Pseudomonadota.

The production of live microalgae represents a major cost in the operation of bivalve hatcheries, as it is the primary food used for larval rearing. This study investigated whether dissolved glucose could reduce the reliance on live microalgae as a sole feed input without negatively affecting bivalve larval performance during the rearing of Greenshell™ mussels (Perna canaliculus). Larvae from a single spawning cohort were raised to Day 10 post-fertilisation and then split into two feeding treatments: (1) control, fed only live microalgae in a continuous flow-through system and (2) glucose treatment, fed live microalgae in a continuous flow-through system, which was interrupted for 2 h, daily during which 10 μg mL⁻¹ of glucose dissolved in seawater, with a 20 min tank flush before and after exposure. The larvae were raised to settlement, during which time growth, microalgae consumption, losses of larvae at screening, settlement success and stable isotope composition (δ¹³C and δ¹⁵N) were assessed. Under these experimental conditions, substituting microalgae with glucose for 2 h daily did not alter the performance or isotopic composition of the larvae despite substituting an estimated 8.3% of live feed. This result provides a foundation to further test and refine the delivery of soluble nutrients, like glucose, as a means to reduce operational costs in bivalve hatcheries.

Yellowfin seabream (Acanthopagrus latus) was basal fed supplemented with low (Mus1: 100 mg/kg) and high (Mus2: 200 mg/kg) doses of lysozyme (200 U/mg) diets, compared to a control group (Mus3: basal fed with no lysozyme) to evaluate lysozyme as an antibiotic alternative. Comprehensive analyses (composition, texture, histological, and untargeted metabolomics) revealed lysozyme promoted growth, muscle development, and flesh quality. Lysozyme supplementation enhanced ash and carbohydrate accumulation significantly (p  < 0.05). Fish in the Mus1 group showed larger muscle fibers and increased myotome density. Metabolomics identified significant shifts in organic acids, lipids, and aromatic compounds. Mus2 enhanced mucosal immunity and retinal accumulation, while reducing fat deposition. Mus1, with a lower lysozyme dose, showed enrichment of the tricarboxylic acid cycle (TCA) cycle activity, accumulating beneficial organic acids (citric and malic acid) and nutritionally critical fatty acids (EPA and DHA), improving muscle quality. This study provides valuable insights into the effects of dietary lysozyme supplementation on yellowfin seabream, with potential applications for optimizing aquaculture practices and identifying key biomarkers for fish health and growth to improve muscle quality and flavor.

This study aims to investigate the effects of potassium diformate (KDF) and sodium propionate (NaP) on gut digestive and immune functions, intestinal microbiota, and lipid metabolites of Trachinotus ovatus based on multiomics approach. Juvenile T. ovatus (initial weight: 8.65 ± 0.02 g) were subjected to a 56-day feeding regimen. Three isonitrogenous and isolipidic diets, including the control (CG), an additional 6.6 g/kg of KDF, and an additional 6.0 g/kg of NaP were fed to juvenile fish twice daily. Results showed that KDF and NaP supplementation significantly increased the activities of chymotrypsin (Chy), lipase (Lip), α-amylase (α-amy), creatine kinase (CK), Na⁺K⁺-ATPase (Na⁺K⁺-ATP), γ-glutamyl transferase (γ-GT), alkaline phosphatase (AKP), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and superoxide dismutase (SOD) as well as the expression level of Nrf2 (p < 0.05), while decreased the pH value, malondialdehyde (MDA) content and the mRNA level of Keap1 (p < 0.05). Dietary KDF and NaP markedly enhanced microbial α-diversity and induced significant shifts in microbiota composition through selective modulation of bacterial populations, such as Photobacterium, Mycoplasma, and Mycobacterium (p < 0.05). Besides, KDF and NaP led to notable alterations in the intestinal metabolite lipidome through increasing short-chain fatty acids (SCFAs) levels, upregulating the abundance of phosphatidylcholine (PC), phosphatidylethanolamine, methyl PC (MePC), lysophosphatidic acid, ceramide (Cer), sitosteryl, monogalactosyldiacylglycerol, coenzyme, and lysophosphatidylethanolamine and downregulating the abundance of sphingomyelin and monoglyceride (p < 0.05). The assessment of associations revealed inverse relationships of digestive and antioxidative indices with Photobacterium, but positive correlations with Mycoplasma, Mycobacterium, Ruegeria, Synechococcus, Nautella, Turicibacter, and Roseovarius. This study advances our understanding of KDF and NaP on intestinal health.