Histological-based characterization of ovarian developmental stages in blue crab (Callinectes sapidus) within the spawning season in the central western Adriatic Sea.

The Atlantic blue crab (Callinectes sapidus Rathbun, 1896) is a euryhaline and eurythermal species native to the Atlantic coasts of the Americas. Although its widespread distribution across the Mediterranean basin is well documented, information on its reproductive patterns remains limited. This study focused on the combination of both macroscopic and histologic characterization of ovarian developmental stages in female blue crabs along the north-central Italian Adriatic coast, within the spawning period.

Synthetic Feed Attractants in European Seabass () Culture: Effects on Growth, Health, and Appetite Stimulation.

Synthetic flavors from standardized processes have recently emerged as a promising and sustainable alternative to traditional feed attractants. In this study, two attractive (F25, cheese; F35, caramel) and one repulsive (F32-, coconut) synthetic flavors were individually added (1% /) to a commercial diet for European seabass () and tested over a 90-day feeding trial (30 fish per tank, in triplicate; initial weight 72.48 ± 8.

Mitigation of Dietary Microplastic Accumulation and Oxidative Stress Response in Rainbow Trout () Fry Through Dietary Supplementation of a Natural Microencapsulated Antioxidant.

Microplastic (MP) contamination in aquafeed poses a significant risk to fish health and safety. This study evaluated the effectiveness of a microencapsulated natural antioxidant, astaxanthin (AX), in mitigating the adverse effects of dietary MPs in rainbow trout fry. The microcapsules were composed of an organic wall matrix designed to preserve AX while limiting MP absorption in the intestine.

New Insights in Microplastic Cellular Uptake Through a Cell-Based Organotypic Rainbow-Trout () Intestinal Platform.

Microplastics (MPs) in fish can cross the intestinal barrier and are often bioaccumulated in several tissues, causing adverse effects. While the impacts of MPs on fish are well documented, the mechanisms of their cellular internalization remain unclear. A rainbow-trout () intestinal platform, comprising proximal and distal intestinal epithelial cells cultured on an Alvetex scaffold, was exposed to 50 mg/L of MPs (size 1-5 µm) for 2, 4, and 6 h.

Cannabidiol can affect morphology, morphometry, enzymatic and microbial activity of rabbit digestive system.

The present research aimed to evaluate the effects of the continuative dietary administration of a hemp oil extract containing cannabinoids (cannabidiol, CBD) on the macroscopic morphology, morphometry, and enzymatic activity of different intestinal tracts as well as on the production of short-chain fatty acids (SCFAs) in the cecum of growing rabbits. The research was performed on 16 rabbits randomly selected from 2 experimental groups (8 per group). In detail, 42 sixty-day-old New Zealand White × California rabbits (sex ratio 1:1, average weight 1621.

The Role of Dietary Fatty Acids in Modulating Blue Crab () Physiology, Reproduction, and Quality Traits in Captivity.

The invasive blue crab is challenging the Mediterranean basin, progressively declining local populations. This reflects a lower prey availability and suitability of dietary nutrients (mainly n-3 polyunsaturated fatty acids, PUFA). The present study aimed to challenge blue crab males and females with a feed source low in n-3 PUFA with respect to one showing a proper fatty acid profile and to investigate the responses in terms of growth, welfare, lipid characterization of target tissues, and reproductive status.

Exploring Photoreceptor Gene Expression and Seasonal Physiology in Mediterranean Swordfish ().

Mature and immature female swordfish show different gonadal expression patterns of melatonin synthesis-related and opsin genes, indicating that seasonality affects gonadal circadian genes, especially through opsin modulation. The high energy demands of reproduction may cause mature female swordfish to become more susceptible to environmental stressors/changes, potentially affecting their health post-reproduction. The modulation of melatonin and opsin expression may also influence swordfish biology, impacting basal metabolism and stress responses.

Replacement of fish meal with full fat modulates hepatic FXR signaling in juvenile rainbow trout (): Exploring a potential role of ecdysteroids.

The present study was conducted to investigate the effects of fish meal (FM) replacement with full fat (HI) on the molecular mechanisms regulating lipid and bile salt (BA) homeostasis in rainbow trout () juveniles. We thus explore the presence of 20-hydroxyecdysone (20E) in an insect meal-based diet and evaluate its potential involvement in regulating the molecular mechanisms/basis of FXR:RXR axis signaling. Ecdysteroids are a category of steroid hormones which bind a nuclear-receptor complex composed of ecdysone receptor (EcR) and ultraspiracle protein (USP) and regulate insect molting and metamorphosis.

Mitigating Dietary Microplastic Accumulation and Oxidative Stress Response in European Seabass () Juveniles Using a Natural Microencapsulated Antioxidant.

Aquafeed's contamination by microplastics can pose a risk to fish health and quality since they can be absorbed by the gastrointestinal tract and translocate to different tissues. The liver acts as a retaining organ with the consequent triggering of oxidative stress response. The present study aimed to combine the use of natural astaxanthin with natural-based microcapsules to counteract these negative side effects.

A Pretty Kettle of Fish: A Review on the Current Challenges in Mediterranean Teleost Reproduction.

The Mediterranean region is facing several environmental changes and pollution issues. Teleosts are particularly sensitive to these challenges due to their intricate reproductive biology and reliance on specific environmental cues for successful reproduction. Wild populations struggle with the triad of climate change, environmental contamination, and overfishing, which can deeply affect reproductive success and population dynamics.

Evaluation of Growth Performance and Environmental Impact of Larvae Reared on Coffee Silverskins Enriched with or Microalgae.

is a promising insect due to its ability to convert low-value substrates as food chain by-products into highly nutritious feed. Its feeding and nutrition are important issues. The aim of this work was to investigate the effect of different substrates consisting of coffee silverskin, a by-product of the roasting process, enriched with different inclusions of microalgae (5%, 10%, 20%, and 25%), and , combined with the assessment of environmental sustainability by LCA.

The Application of Synthetic Flavors in Zebrafish () Rearing with Emphasis on Attractive Ones: Effects on Fish Development, Welfare, and Appetite.

The aim of the present study was to test synthetic flavors as potential feed attractants in zebrafish () during early development. Six experimental groups were set up in triplicate: (i) a CTRL group fed a zebrafish commercial diet; (ii) a PG group fed a control diet added with Propylene Glycol (PG); (iii) A1 and A2 groups fed a control diet added with 1% of the two attractive flavors (A1 cheese odor made by mixing Propylene Glycol (PG) with the aromatic chemicals trimethyamine, 2-acetylpyrazine, 2-acetylpyridine, and dimethyl sulfide; and A2 caramel odor, made of PG mixed with the aromatic chemicals vanillin, maltol, cyclotene, acetoin, butyric acid, and capric acid with traces of both gamma-octalactone and gamma-esalactone) or the repulsive flavor (A coconut odor, made by mixing PG with the aromatic chemicals gamma-eptalactone, gamma-nonalactone, delta-esalactone, and vanillin with trace of both delta-octalactone and maltol), respectively; (iv) an ROT group fed the two attractive diets, each administered singularly in a weekly rotation scheme. All the tested synthetic flavors did not affect the overall health of larval and juvenile fish and promoted growth.

Dietary Microplastic Administration during Zebrafish () Development: A Comprehensive and Comparative Study between Larval and Juvenile Stages.

One of the main sources of MPs contamination in fish farms is aquafeed. The present study investigated, for the first time through a comparative approach, the effects of different-sized fluorescent MPs included in a diet intended for zebrafish (). A comparison based on fish developmental stage (larval vs.

Enhancing Rearing of European Seabass () in Aquaponic Systems: Investigating the Effects of Enriched Black Soldier Fly () Prepupae Meal on Fish Welfare and Quality Traits.

Within the modern aquaculture goals, the present study aimed to couple sustainable aquafeed formulation and culturing systems. Two experimental diets characterized by 3 and 20% of fish meal replacement with full-fat spirulina-enriched black soldier fly () prepupae meal (HPM3 and HPM20, respectively) were tested on European seabass () juveniles during a 90-day feeding trial performed in aquaponic systems. The experimental diets ensured 100% survival and proper zootechnical performance.

Growth and Welfare Status of Giant Freshwater Prawn () Post-Larvae Reared in Aquaponic Systems and Fed Diets including Enriched Black Soldier Fly () Prepupae Meal.

Due to the limited application of insect meal in giant freshwater prawn () culture, the present study aimed to (i) produce spirulina-enriched full-fat black soldier fly () prepupae meal (HM) and (ii) test, for the first time, two experimental diets characterized by 3% or 20% of fish meal and fish oil replacement with full-fat HM (HM3 and HM20, respectively) on post-larvae during a 60-day feeding trial conducted in aquaponic systems. The experimental diets did not negatively affect survival rates or growth. The use of spirulina-enriched HM resulted in a progressive increase in α-tocopherol and carotenoids in HM3 and HM20 diets that possibly played a crucial role in preserving prawn muscle-quality traits.

Spirulina-enriched Substrate to Rear Black Soldier Fly () Prepupae as Alternative Aquafeed Ingredient for Rainbow Trout () Diets: Possible Effects on Zootechnical Performances, Gut and Liver Health Status, and Fillet Quality.

In the present study, an organic substrate (coffee silverskin) enriched with spirulina (; 15% /), as a source of lipids and bioactive molecules, was used to rear the black soldier fly () prepupae. Three grossly isonitrogenous, isoproteic, isolipidic and isoenergetic experimental diets for rainbow trout () juveniles were then produced: a control diet (HM0) mostly including fish meal and fish oil, and two other test diets named HM3 and HM20, in which 3 or 20% of the marine ingredients were substituted with full fat black soldier fly prepupae meal (HM), respectively. Experimental diets were provided for 6 weeks, and at the end of the trial the physiological responses and marketable traits of the fish were investigated using a multidisciplinary approach.

Towards the Identification of a Suitable Commercial Diet for Carpione (, Linnaeus 1758): A Multidisciplinary Study on Fish Performances, Animal Welfare and Quality Traits.

Carpione (, Linnaeus 1758) is an endangered precious endemism of Lake Garda (Northern Italy), the largest Italian lake. To date, several bottlenecks about its culture remain unsolved, including the identification of a proper growth-out diet. The aim of the present study was to test four different grossly isolipidic, isoproteic, and isoenergetic diets in which the main ingredients had a different origin.

New Eco-Sustainable Feed in Aquaculture: Influence of Insect-Based Diets on the Content of Potentially Toxic Elements in the Experimental Model Zebrafish ().

According to the concept of circular economy, insects represent good candidates as aquafeed ingredients. Nevertheless, there are some potential chemical risks linked with insect consumption. In this study, we reared the teleost , used as an experimental model, with five experimental diets characterized by increasing levels (0%, 25%, 50%, 75%, and 100%) of full-fat (Hi) prepupae, substituting for fish meal (FM) and fish oil (FO).

and Poultry by-Product Meals as Alternatives to Plant Protein Sources in Gilthead Seabream () Diet: A Multidisciplinary Study on Fish Gut Status.

The attempt to replace marine-derived ingredients for aquafeed formulation with plant-derived ones has met some limitations due to their negative side effects on many fish species. In this context, finding new, sustainable ingredients able to promote fish welfare is currently under exploration. In the present study, poultry by-products and meal were used to replace the vegetable protein fraction in diets totally deprived of fish meal intended for gilthead seabream ().

Possible Dietary Effects of Insect-Based Diets across Zebrafish () Generations: A Multidisciplinary Study on the Larval Phase.

Insects represent a valuable and sustainable alternative ingredient for aquafeed formulation. However, insect-based diets have often highlighted controversial results in different fish species, especially when high inclusion levels were used. Several studies have demonstrated that nutritional programming through parental feeding may allow the production of fish better adapted to use sub-optimal aquafeed ingredients.

Microbial dynamics in rearing trials of Hermetia illucens larvae fed coffee silverskin and microalgae.

In the present study, Hermetia illucens larvae were reared on a main rearing substrate composed of a coffee roasting byproduct (coffee silverskin, Cs) enriched with microalgae (Schizochytrium limacinum or Isochrysis galbana) at various substitution levels. The microbial diversity of the rearing substrates, larvae, and frass (excrement from the larvae mixed with the substrate residue) were studied by the combination of microbial culturing on various growth media and metataxonomic analysis (Illumina sequencing). High counts of total mesophilic aerobes, bacterial spores, presumptive lactic acid bacteria, coagulase-positive cocci, and eumycetes were detected.

Occurrence of Antibiotic Resistance Genes in Larvae Fed Coffee Silverskin Enriched with or Microalgae.

larvae are among the most promising insects for use as food or feed ingredients due to their ability to convert organic waste into biomass with high-quality proteins. In this novel food or feed source, the absence of antibiotic-resistant bacteria and their antibiotic resistance (AR) genes, which could be horizontally transferred to animal or human pathogens through the food chain, must be guaranteed. This study was conducted to enhance the extremely scarce knowledge on the occurrence of AR genes conferring resistance to the main classes of antibiotics in a rearing chain of larvae and how they were affected by rearing substrates based on coffee silverskin supplemented with increasing percentages of or microalgae.

Physiological responses of Siberian sturgeon (Acipenser baerii) juveniles fed on full-fat insect-based diet in an aquaponic system.

Over the last years, the potential use of Black Soldier Fly meal (BSF) as a new and sustainable aquafeed ingredient has been largely explored in several fish species. However, only fragmentary information is available about the use of BSF meal-based diets in sturgeon nutrition. In consideration of a circular economy concept and a more sustainable aquaculture development, the present research represents the first comprehensive multidisciplinary study on the physiological effects of a BSF diet during sturgeon culture in an aquaponic system.