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The absence of a controlled diet is unfortunate in a promising model organism for ageing, the turquoise killifish (Nothobranchius furzeri Jubb, 1971). Currently captive N. furzeri are fed bloodworms but it is not known whether this is an optimal diet. Replacing bloodworms with a practical dry feed would reduce diet variability. In the present study, we estimated the nutritional value of the diet ingested by wild fish and determined the fish-body amino acid profile as a proxy for their nutritional requirements. We compared the performance of fish fed four commercial feeds containing 46%-64% protein to that achieved with bloodworms and that of wild fish. Wild fish target a high-protein (60%) diet and this is supported by their superior performance on high-protein diets in captivity. In contrast, feeds for omnivores led to slower growth, lower fecundity and unnatural liver size. In comparison to wild fish, a bloodworm diet led to lower body condition, overfeeding and male liver enlargement. Out of the four dry feeds tested, the fish fed Aller matched wild fish in body condition and liver size, and was comparable to bloodworms in terms of growth and fecundity. A starter feed for carnivorous species appears to be a practical replacement for bloodworms for N. furzeri. The use of dry feeds improved performance in comparison to bloodworms and thus may contribute to reducing response variability and improving research reproducibility in N. furzeri research.

Pickering emulsions have been known to be promising candidates for encapsulating and delivering a wide range of bioactive compounds with antioxidant potentials. In this work, we formulated and characterized zein (ZN)/chitosan (CS) stabilized Pickering emulsion. The prepared emulsions were firstly characterized by droplet size after preparation and after storage for one month at room temperature as well as after the addition of prebiotic gum Arabic (GA). Rheological measurements were further carried out to see the behavior and stability of these emulsions after storage. Thereafter, vit-D3 was encapsulated, and the antioxidant activity of the emulsions system were evaluated. The results showed that no significant change in the mean droplet diameter of the emulsions was observed after storage for a month. This claim was further confirmed by their rheological measurements particularly, the emulsions prepared with ZN/CS ratio of 1:2 having 50% oil contents exhibited significant stability. GA addition caused a gradual increase in the droplet size up to some level, after which it led to complete destabilization of the emulsion. Finally, to protect and deliver, vit-D3 was successfully loaded in these emulsions. No significant difference in the DPPH radical scavenging activity of the vit-D3 encapsulated emulsions was observed, showing their capability as delivery vehicles irrespective of their composition.

Background Presently, ~68.6 million tons of chilled-stored seafood are available globally for human consumption, worth ~129.5 billion €. At least ~13.7 million tons (worth 25.8 billion €) are probably spoilt each year, from post-catch till consumption. A growing interest in essential oils (EOs) as bio-preservatives in chilled-stored seafood is recently visible – prolific research during 2015–2020. Scope and approach Data from 180 scientific articles were reviewed and meta-analyzed. Our data-driven review aims to corroborate the promises of EOs in the chilled-stored seafood industry– where we stand and where to go (?). Key findings and conclusions Microbial load explain 60–90% of spoilage indicators’ progression in chilled-stored fish flesh. Beyond TVC 5–7 log CFU g−1, spoilage progresses exponentially. We identified 6 EOs with extraordinary TVC reduction potential (>4.61 log CFU g−1 per % concentration) that can ensure compliance with EU safety standards for raw fish – citrus, mentha, origanum, thymus, zataria, and zingiberaceae (probably chamomile and star anise in future). Not all EOs can suppress all specific microbes, especially anaerobic H2S producing bacteria. Only origanum, zingiberaceae, and thymus have complete-spectrum efficacy. Their right application method is essential (hurdle technology; active film-nanonemulsion; special packaging). 0.5–1% concentration of most EOs impart little interference on the natural odor of fresh fish. The rate of sensory score deterioration in EO treated fish flesh is ~2.5–5 times slower than normal refrigerated ones. Selected EOs at mild concentrations with the right application method can promote safety, sensory and shelf-life agendas of chilled-stored seafood. The guidelines, warnings, knowledge gaps, and research needs are discussed.

Background Pickering emulsions (PEs) which are stabilized by solid particles instead of surfactants have recently attracted tremendous attentions due to their non-toxic and long-term stable nature. In the current study, we fabricated and characterized zein (ZN)/chitosan (CS) complex particles (ZNCSPs) stabilized PE for the encapsulation and delivery of vitamin D3 . Results The ZNCSPs were synthesized with different ratios, i.e. 1:1, 1:1.5 and 1:2 to investigate the optimum ratio. Transmission electron microscopy observations showed the spherical nature with smooth surface of the obtained particles in the case of ZNCS ratio 1:1.5 and 1:2. Furthermore, ζ-potential values for the these particles were 32.53 ± 1.3 and 52.86 ± 0.68 mV respectively, indicating particles with (1:2) being more stable than 1:1.5. Thereafter, using these particles, the PEs were successfully formulated with different oil (medium chain triglyceride) fractions (330, 500 and 660 g kg-1 ). The emulsions were evaluated for stability during storage and against different environmental factors including pH, temperature and ionic strength on the creaming indices (CIs) of these emulsions. The results demonstrated that the PEs with oil fractions 330 and 500 g kg-1 exhibited significant stability during storage, particularly the ones with 500 g kg-1 oil fractions which were stable against all the tested parameters. Finally, the prepared PEs were evaluated as efficient delivery system by encapsulating and delivering vitamin D3 . In vitro drug release profile confirmed sustained and controlled release of the encapsulated vitamin D3 . Conclusion Overall, our findings suggest that ZNCSPs can be promising stabilizers for stable PEs that can be used as potential delivery systems in food, cosmetic and pharmaceutical industries. © 2021 Society of Chemical Industry.

Even though aquaponics is the production system that is increasingly gaining focus, there is an absence of publications studying the use of pesticides in the aquaponics. Therefore, the aim of this study was to assess negative effects of one synthetic (chlorpyrifos) and two botanical insecticides (azadirachtin and pyrethrin) to matured biofilter in plastic buckets. The effectiveness of biofilter bacteria is determined indirectly, as concentrations of ammonia, nitrites and nitrates in the water were measured at 0h, 5h, 13h, 21h, 29h, 37h, 45h and 53h after insecticides application. The results showed negative effects of azadirachtin on the first step of nitrification, as concentration of ammonia was higher comparing to other groups for almost every sample point. Negative effects on second step of nitrification and higher concentrations of nitrites in the water were also detected, but no statistical differences were observed in the present study, due to the large variation between buckets. Nitrates were lower in water treated with azadirachtin from 29 hours from start to the end of the experiment. Application of other two insecticides to biofilter did not cause any effects and showed no difference comparing to the control group.

The zebrafish (Danio rerio) genome contains a single gene fads2 encoding a desaturase (FADS2) with both Δ6 and Δ5 activities, the key player in the endogenous biosynthesis of long-chain polyunsaturated fatty acids (LC-PUFAs), which serve essential functions as membrane components, sources of energy and signaling molecules. LC-PUFAs include the precursors of eicosanoids and are thus predicted to be indispensable molecules for reproductive health in virtually all vertebrates. In mice, an amniotic vertebrate, fads2 deletion mutants, both males and females, have been confirmed to be sterile. In anamniotic vertebrates, such as fish, there is still no information available on the reproductive (in)ability of fads2 mutants, although zebrafish have become an increasingly important model of lipid metabolism, including some aspects of the generation of germ cells and early embryonic development. In the present study, we apply the CRISPR/Cas9 genome editing system to induce mutations in the zebrafish genome and create crispants displaying a degree of fads2 gene editing within the range of 50–80%. Focusing on adult G0 crispant females, we investigated the LC-PUFA profiles of eggs. Our data suggest an impaired pathway of the LC-PUFA biosynthesis of the ω6 and ω3 series in the first-rate limiting steps of the conversion of linoleic acid (LA) into γ-linolenic acid (GLA), and α-linolenic acid (ALA) into stearidonic acid (SDA), respectively, finally resulting in bad-quality eggs. Our data suggest the existence of an alternative Δ8 pathway, which bypasses the first endogenous LC-PUFA biosynthetic step in zebrafish in vivo, and suggest that the zebrafish bifunctional FADS2 enzyme is actually a trifunctional Δ6/Δ5/Δ8 desaturase.

The growing importance of aquaculture products for human health also raises the question of product sustainability and decreasing its costs. Insects are considered as novel feed ingredients and source of proteins. In this study, a twelve-week feeding trial with replacement of 25% fishmeal by a mixture of house cricket (Acheta domesticus) and superworm (Zophobas morio) in the fish feed was conducted with perch (Perca fluviatilis). There were no significant differences in this feeding trial, regarding survival, but decreased fish growth and increased feed conversion between the control and the experimental fed groups. Hepatic cytochrome P450 (CYP1A and CYP3A-like) activity and fatty acid (FA) composition were assessed in perch also. No significant effects were observed on cytochrome P450 activity associated with presence of toxic compounds in fish. Feeding with insect pellets resulted in significant increasing of linoleic FA and an increase of the total content of n-6 FA in fish fillets, compared to the fish fillets from control group. However, changes in FA composition were only minor and did not affect the nutritional value of the fish with insect-based diet for human consumption. Further evaluation should be conducted with different ratios or different insect species.

Screening of novel feedstuffs, that too for data-deficient (nutritionally) animals, is somewhat ambiguous or problematic. Through systematic meta-analyses, the present study formulated most up-to-date crayfish nutritional standards, against which a recyclable waste (biofloc biomass, BM) from intensive aquaculture systems was assessed as a novel protein source. Growth trajectory dependencies and thermal growth coefficient qualifying for good growth in crayfish (TGC 0.5–0.64 units) were benchmarked. Using these standards and a 7-week growth trial, BM's suitability as a novel protein source for red swamp crayfish Procambarus clarkii was evaluated through its graded inclusions in a commercial feed. Results suggest that BM can elevate growth at 33–66% inclusion in existing feed formulations. Beyond 66% inclusion, BM can deteriorate growth in crayfish due to high ash content (exceeding physiological limit > 14%), arginine deficiency (~ 14–20% lower than an optimum requirement), and insufficient non-protein energy: protein ratio (3.7 cal mg−1). Arginine is perhaps the most critical amino acid in dietary protein for crayfish, and deficient in BM. Although no critical bioaccumulation levels of heavy metals were breached by feeding 100% BM to crayfish, a mineral and heavy metal (Hg) stress seemed plausible. Crayfish raised solely on biofloc may not realize full growth potential.

Omega-3 common carp (OCC) raised by patented culture systems have higher level of n-3 fatty acids and n-3/n-6 ratio than normal common carps (NCCs) from traditional culture system. Whether the patented farming system and modified fatty acid profile will influence OCC storage stability is unclear. This study aimed to expose the differences of post-mortem quality changes between NCC and OCC.NCC and OCC have similar rigor mortis patterns, only a higher level of lactic acid was observed in NCC after 96 h. Adenosine triphosphate (ATP) related compounds had no major differences, but slightly higher inosine monophosphate in OCC was found at 36 h. The K-value, Ki-value and Hx-index demonstrated high cohesiveness (Pearsons two-tailed, r = 0.968-0.984, P 0.05) during storage, with statistically comparable (P 0.05) temporal progress of change in NCC and OCC. The indices were lower in OCC than in NCC. Attenuation of myosin heavy chain in OCC was not as distinct as in NCC, coincided with its higher salt-soluble protein level at 144 h. Before 96 h, thiobarbituric acid value (TBA), total viable count (TVC), cooking loss (CL), drip loss (DL), and hardness in NCC and OCC were similar. However, at 144 h, higher TBA, TVC, CL and DL while lower hardness in NCC than in OCC were observed. Principle component analysis showed good separation of NCC and OCC in biplot at 0 and 144 h.Patented culture system has a slightly positive influence on post-mortem quality of common carp. It can be used for producing OCC without compromising storage stability. © 2020 Society of Chemical Industry.

Background Dietary fibers (DFs) are known as potential formulations in human health due to their beneficial effects in control of life-threatening chronic diseases including cardiovascular disease (CVD), diabetes mellitus, obesity and cancer. In recent decades scientists around the globe have shown tremendous interest to evaluate the interplay between DFs and gastrointestinal (GIT) microbiota. Evidences from various epidemiological and clinical trials have revealed that DFs modulate formation and metabolic activities of the microbial communities residing in the human GIT which in turn play significant roles in maintaining health and well-being. Furthermore, interestingly, a rapidly growing literature indicates success of DFs being prebiotics in immunomodulation, namely the stimulation of innate, cellular and humoral immune response, which could also be linked with their significant roles in modulation of the probiotics (live beneficial microorganisms). Scope and approach The main focus of the current review is to expressively highlight the importance of DFs being prebiotics in human health in association with their influence on gut microbiota. Now in order to significantly achieve the promising health benefits from these prebiotics, it is aimed to develop novel formulations to enhance and scale up their efficacy. Therefore, finally, herein unlike previously published articles, we highlighted different kinds of prebiotic and probiotic formulations which are being regarded as hot research topics among the scientific community now a days. Conclusion The information in this article will specifically provide a platform for the development of novel functional foods the demands for which has risen drastically in recent years., Highlights • Dietary fibers (DFs) play significant role in improving human health. • The effects of DFs in control of chronic diseases and viral infections was described. • The importance of dietary fibers being prebiotics was highlighted in detail. • Encapsulation of pre and prebiotics for their protection in gut environment is crucial. • Advancements in new pre & probiotics-based formulations have been focused.

BACKGROUND: Aquaculture is the fastest growing food‐production sector, and common carp (Cyprinus carpio) is one of the most cultivated fish species in the world. Due to its intrinsic characteristics, fish meat is highly susceptible to microbiological spoilage. Pseudomonas and Shewanella are the primary and secondary occurring microbiota during storage of fish meat, with significant contribution to spoilage with the formation of hydrolytic enzymes (lipases and proteases). RESULTS: With in vitro testing, we show that rosemary extract (Inolens4), buffered vinegar and their combination (SyneROX) exhibit antimicrobial effects against P. fragi, P. psychrophila, S. putrefaciens and S. xiaemensis at concentrations of 3.13 and 1.56 mg mL⁻¹. The combination was the most effective in inhibiting growth of selected bacteria in food model, and production of lipases and proteases during 9 days at 5 °C. In situ testing of antimicrobial dip treatment of carp meat determined that aerobic mesophilic, total psychrotrophic, Pseudomonas and hydrogen sulfide producer counts were reduced in all treatments, with the most prominent influence being shown by the combination and buffered vinegar. CONCLUSIONS: Our study highlights the importance of a multilevel assessment of the antimicrobial potential of biopreservatives under conditions comparable to those of the selected food. Investigation with bacteria and food model provided coherent and consistent data for the evaluation of the antimicrobial potential for carp meat. Combination of buffered vinegar (as active antimicrobial) and rosemary extract, with well‐known and researched antioxidant properties but low in situ antimicrobial activity, represents a good potential for combined effect in preservation of fish meat. © 2020 Society of Chemical Industry

Fish fillets are susceptible to microbial spoilage during chilled storage. Green consumerism promotes the development of biodegradable, recyclable and environmentally friendly food packaging. The study selected three essential oils (EOs), i.e. thyme, oregano and pimento EO, with good antibacterial activity, to develop an EO-emulsion based alginate coating. A stable alginate coating with good antibacterial effects could be prepared under optimized conditions of homogenization (18,000 rpm, 3 min) and EO/Tween-80 ratio (20:1, v/v). When loaded with 1% EO-emulsion, the coating showed good antibacterial effects with a high-value sensory assessment. No effect was found on the coating properties under different temperatures (4 and 20 °C) and pH conditions (6, 7 and 8). Alginate coatings with 1% thyme, oregano, pimento EO-emulsion were applied for chill-stored carp fillets. All coatings with EO-emulsion delayed pH change, decreased total volatile basic nitrogen and total viable count and inhibited Pseudomonas sp., H2S-producing bacteria and Enterobacteriaceae.

The zebrafish (

Simple Summary It is important to consider the nutritional requirements and optimum feeding of hatchery-raised, conservation-priority rheophilic fishes meant for river stock enhancement. Properly selected diets for these nutritionally data-poor fish species are crucial to achieve optimum growth potential and physiology. It greatly reduces the time spent in captivity, and if properly trained, may produce fish that are better insured for facing hardships in the wild. Abstract Large-bodied, river-migrating, rheophilic fishes (cyprinids) such as barbel Barbus barbus, nase Chondrostoma nasus, asp Leuciscus aspius, and vimba bream Vimba vimba are threatened in major European drainages. This represents the subject of our present study. Their hatchery nutrition prior to river-release is mostly on a hit-and-trial or carp-based diet basis. The study demonstrates an alternative approach to decide optimum nutrition for these conservation-priority and nutritionally data-poor fishes. The study revealed barbel as a central representative species in terms of wild body composition among other native rheophilic cyprinids considered (asp, nase, vimba bream). Taking barbel as a model, the study shows that barbel or rheophilic cyprinids may have carnivorous-like metabolism and higher requirements of S-containing, aromatic, branched-chain amino acids (AAs) than carps. Besides, there are important interactions of AAs and fatty acids (FAs) biosynthesis to consider. Only proper feeding of nutritionally well-selected diets may contribute to river stocking mandates such as steepest growth trajectory (≈less time in captivity), ideal size-at-release, body fitness (≈blend-in with wild conspecifics, predator refuge), better gastrointestinal condition, maximized body reserves of functional nutrients, and retention efficiencies (≈uncompromised physiology). Considering important physiological functions and how AA–FA interactions shape them, hatchery-raised fishes on casually chosen diets may have high chances of physiological, morphological, and behavioral deficits (≈low post-stocking survivability). Based on the observations, optimum nutrient requirements of juvenile (0+ to 1+ age) barbels are suggested. Future efforts may consider barbels as a nutrition model for conservation aquaculture of threatened and data poor rheophilic cyprinids of the region.

Pickering emulsions have been known to be promising candidates for encapsulating and delivering a wide range of bioactive compounds with antioxidant potentials. In this work, we formulated and characterized zein (ZN)/chitosan (CS) stabilized Pickering emulsion. The prepared emulsions were firstly characterized by droplet size after preparation and after storage for one month at room temperature as well as after the addition of prebiotic gum Arabic (GA). Rheological measurements were further carried out to see the behavior and stability of these emulsions after storage. Thereafter, vit-D

Proximate composition and amino and fatty acid profiles of peled fillets of both sexes reared in a pond-based system (PS) and intensively cultured in a recirculating aquaculture system (RS) were co...

The effects of three concentrations (0.5, 1.0 and 2%) of rosemary extract “Inolens 4” and control (without additive) on microbiological quality, sensory attributes, colour parameters and oxidative stability of rainbow trout (Oncorhynchus mykiss) fillets during refrigerated storage after different periods (0, 3, 6, 10 and 14 days) were investigated. Microbial communities grew to between 1.93 and 2.29 colony-forming units per gramme (log CFU g−1), 5.10 and 5.27, 5.12 and 5.80 and 6.34 and 7.66 log CFU g−1 after 0, 6, 8 and 10 days of storage, respectively, and fillets treated with Inolens 0.5 showed the lowest total viable counts among all analysed groups. Also, sensory analyses showed that Inolens 0.5 achieved best scores in all sensory attributes of cooked flesh. Evaluation of lipid oxidation parameters proved that treatment with Inolens 4 had a positive effect, leading to delay oxidation processes in flesh.

The current knowledge on how different Eurasian perch rearing systems impact the final fillet quality is scant. Therefore, two domestic storage conditions were investigated-10 months frozen (-20 degrees C) and 12 days refrigerated (+4 degrees C) storage conditions-in order to determine (i) how the choice of rearing system affects fillets quality during different processing conditions and (ii) if oxidative changes and other quality parameters were interactive. For the proposed idea, proteome analysis, oxidative changes, and some quality parameters were considered in this study. Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) indicated a higher loss of protein in the frozen fillets from ponds (PF) than the fillets from recirculating aquaculture systems (RAS) (RF). Western blot showed a higher protein carbonyls level in RF compared to PF, which was confirmed by the total protein carbonyls during frozen storage. PF indicated less liquid loss, hardness, and oxidation progress than RF in both storage conditions. The biogenic amines index (BAI) in the fillets from either origin showed acceptable levels during storage at +4 degrees C. Furthermore, the n-3/n-6 ratio was similar for both fillets. The deterioration of fillets during frozen storage was mainly caused by formation of ice crystals followed by protein oxidation, while protein oxidation was the main concern during refrigerated storage confirmed by principal component analysis (PCA) analysis.

Powders prepared from freeze-dried roots of six beetroot ( Beta vulgaris L.) cultivars with red (cv. D'Egypte, Karkulka, Betina, Alexis), yellow (cv. Burpee's Golden) or red-white (cv. Chioggia) colour of root flesh were evaluated before and after boiling treatment (20 min, 100°C). Water and fat holding capacity (WHC and FHC), colour, contents of betalains and total phenolics (TPCs), and antioxidant activity were all significantly affected by cultivar as well as powder thermal treatment. WHC increased after boiling of the powder and varied between cultivars from 2.14 g/g (cv. D'Egypte) to 2.59 g/g (cv. Chioggia). The highest FHC of 1.22 g/g was observed in cv. Betina. Colour stability was optimal in the cultivars with red root flesh; with their lightness decrease between 6 and 10%. This corresponded with betalain content that was the highest in red cv. Betina; for which the values before and after boiling were 18.10 and 15.04 mg/g DM, respectively. Cultivar Betina significantly exceeded the other cultivars also in TPCs and antioxidant activity. The TPCs values of this cultivar were 3.73 and 3.32 mg gallic acid equivalents/g DM in the unboiled and boiled variant, respectively. Antioxidant activity of Betina powder before and after boiling was 11.13 and 11.69 mg ascorbic acid equivalents/g DM, respectively. The results indicated the significance of beetroot cultivar selection for thermal processing. Beetroots with red flesh significantly exceeded yellow and red-white cultivars in all the evaluated characteristics.

Mechanically separated fish meat (MSFM) can be used for the manufacturing of ready-to-eat products, such as sausages, however, it is highly perishable. Several plant by-products, including onion peel, which is rich in polyphenol antioxidants, can be added to food to extend shelf life. This study investigated the effects of the addition of onion peel powder (OPP) to sausage made from MSFM. Sausages were divided into four groups with different amounts of added OPP: 0% (control), 1%, 2%, and 3%. Cooked sausages were stored for 28 days at 5 &deg, C. Samples were analyzed for thiobarbituric acid reactive substances, antioxidant activity, total polyphenol content, pH, and organoleptic properties. The addition of OPP significantly increased antioxidant activity and total polyphenol content and decreased pH, indicating acidic nature of OPP. Polyphenols from OPP effectively suppressed lipid oxidation. A 1&ndash, 2% addition of OPP enhanced sensory properties. After the 28-day storage, the control samples received the lowest sensory score, due to the presence of a strong fishy odor, which was not present in samples with OPP. HPLC&ndash, MS/MS analysis revealed that quercetin is the most dominant compound in OPP. Overall, the results indicate that the addition of OPP in amounts of 1&ndash, 2% can extend shelf life, without the deterioration of sensory properties.

Fatty acid desaturase 2 (Fads2) is the key enzyme of long chain polyunsaturated fatty acid (LC-PUFA) biosynthesis. Endogenous production of these biomolecules in vertebrates, if present, is insufficient to meet demand. Hence, LC-PUFA are considered as conditionally-essential. At present however, LC-PUFA are globally-limited nutrients due to anthropogenic factors. Attention of research is given therefore to find ways to maximize endogenous LC-PUFA production especially in production species, whereby deeper knowledge on molecular mechanisms of enzymatic steps involved is being generated. This review first briefly informs about the milestones in the history of LC-PUFA essentiality exploration before it focuses on the main aim – to highlight the fascinating Fads2 potential to play roles fundamental to adaptation to novel environmental conditions. Investigations are summarized, which elucidate the evolutionary history of fish Fads2 providing an explanation for the remarkable plasticity of this enzyme in fish. Further, structural implications of Fads2 substrate specificity are discussed and some relevant studies performed on organisms other than fish are mentioned in cases when such studies have so far not been conducted on fish models. The importance of Fads2 in the context of growing aquaculture demand and dwindling LC-PUFA supply is depicted and a few remedies in the form of genetic engineering to improve endogenous production of these biomolecules are outlined.

Digestive enzymes are found in the digestive tract of animals which assist in the breakdown of larger food molecules into more easily absorbed particles that can then be used by the body. The ability of fish to break down a diet is highly dependent on the availability of suitable digestive enzymes which mediate specific degradation pathways and on both the physical and chemical nature of food. Probiotics are known to produce helpful enzymes that aid in digestion and protect the gastrointestinal tract (GIT) of animals. When applied appropriately, probiotics improve intestinal microbial balance which also improves digestive enzyme activities, food absorption, and decrease pathogenic issues in the GIT. They work hand-in-hand with the digestive enzymes in the GIT of animals as supplements thereby improvings nutrition. This in turn leads to higher feed efficiency and growth as well as the prevention of antinutritional factors present in the ingredients, intestinal disorders, and pre-digestion. This review seeks to present summaries of the results of research findings on the application of probiotics on the activities of digestive enzymes including amylase, lipase, and protease. Further, this review points out gaps in available literature and suggests ideas that could be explored in further investigations to better understand and enhance the activities of these digestive enzymes to increase feed and nutrient utilization and the production of aquaculture species.

The influence of rotifers (Brachionus plicatilis) on pikeperch performance during first feeding was investigated. Significant differences between treatments were found in length, body weight, survival, feed consumption, fatty acid composition, and RNA/DNA ratio. Pikeperch larvae (Sander lucioperca) were reared under three different diets (artemia nauplii (A), artemia nauplii/rotifers (B), and rotifers (C)), during the first 17 days post hatch (dph). Final performance parameters in total length, myomere height (MH), body weight, eye diameter, stomach fullness, survival, fatty acid composition, and RNA/DNA ratio were measured and compared among treatments. In terms of growth (length, body weight, and myomere height) and stomach fullness, the larvae from treatment B excelled over the other two treatments. Survival and key fatty acids such as docosahexaeonic acid (DHA) were higher in treatment C. Results suggest that the most favorable diet during larval pikeperch first feeding is a mixed diet (rotifers/artemia). This feeding method can significantly increase efficiency of pikeperch larval culture on a commercial scale. Yet, more accurate weaning protocols of this diet during the first 12–17 dph need to be developed to further improve larval performance.