Histological and molecular characterization of the digestive system of early weaned juveniles of Arapaima sp. reared in a recirculating aquaculture system.

Arapaima spp., the world's largest scaled freshwater fish, native to the Amazon and Essequibo river basins, are valued in aquaculture for their rapid growth and ornamental appeal. However, reliance on natural breeding and parental care in earthen ponds results in variable fingerling survival, hindering production.

are a potential source of novel colistin-resistance genes in European coastal environments.

Colistin is a widespread last resort antibiotic for treatment of multidrug-resistant bacteria. The recent worldwide emergence of colistin resistance (Col-R) conferred by -1 in human pathogens has raised concern, but the putative sources and reservoirs of novel genes in the marine environment remain underexplored. We observed a high prevalence of Col-R, particularly in isolated from European coastal waters by using the same cohorts of oysters as bioaccumulators in three sites across Europe.

Proficiency testing and cross-laboratory method comparison to support standardisation of diatom DNA metabarcoding for freshwater biomonitoring.

DNA metabarcoding of benthic diatoms has been successfully applied for biomonitoring at the national scale and can now be considered technically ready for routine application. However, protocols and methods still vary between and within countries, limiting their transferability and the comparability of results. In order to overcome this, routine use of DNA metabarcoding for diatom biomonitoring requires knowledge of the sources of variability introduced by the different steps of the procedure.

Depuration of and in Comparison with in Mussels () and Oysters ().

-related species are considered emerging food-borne and waterborne pathogens, with shellfish being a suggested reservoir. In a published study that investigated 204 shellfish samples and 476 isolates, the species (now known as ) and (now known as ) have been isolated as the most dominant species. However, the efficiency of depuration for eliminating and in comparison with from mussels and oysters is unknown and is therefore the objective of this investigation.

Comparative study of the gut microbial communities collected by scraping and swabbing in a fish model: a comprehensive guide to promote non-lethal procedures for gut microbial studies.

In the present study, we propose the use of swabs in non-lethal sampling procedures to collect the mucosa-adhered gut microbiota from the posterior intestine of fish, and therefore, we compare the bacterial communities collected by conventional scraping and by swabbing methods. For this purpose, samples of the posterior intestine of rainbow trout () were collected first using the swabbing approach, and after fish euthanasia, by mucosa scraping. Finally, bacterial communities were compared by 16S rRNA gene Illumina sequencing.

Corrigendum: Trophic diversification and parasitic invasion as ecological niche modulators for gut microbiota of whitefish.

[This corrects the article DOI: 10.3389/fmicb.2023.

Impact of the diet in the gut microbiota after an inter-species microbial transplantation in fish.

Inter-species microbial transplantations offer the possibility of transferring species-specific microbes and their associated functionality. As a conceptual approach, an intestinal microbiota transplant (IMT) between two marine carnivorous fish species that thrive in different environmental conditions was conducted: from donor Atlantic salmon (Salmo salar) to recipient gilthead seabream (Sparus aurata), after obliterating its basal microbiota with an antibiotic treatment. To confirm that the gut microbiota was able to recover after antibiotics without the influence of the diet, a group of gilthead seabream not submitted to the IMT was kept fasted as an internal control.

Microbiome study of a coupled aquaponic system: unveiling the independency of bacterial communities and their beneficial influences among different compartments.

To understand the microbiome composition and interplay among bacterial communities in different compartments of a coupled freshwater aquaponics system growing flathead grey mullet (Mugil cephalus) and lettuces (Lactuca sativa), 16S rRNA gene amplicon sequencing of the V3-V4 region was analysed from each compartment (fish intestine, water from the sedimentation tank, bioballs from the biological filter, water and biofilm from the hydroponic unit, and lettuce roots). The bacterial communities of each sample group showed a stable diversity during all the trial, except for the fish gut microbiota, which displayed lower alpha diversity values. Regarding beta diversity, the structure of bacterial communities belonging to the biofilm adhering to the hydroponic tank walls, bioballs, and lettuce roots resembled each other (weighted and unweighted UniFrac distances), while bacteria from water samples also clustered together.

Rearing European Eel () Elvers in a Biofloc System.

European eel () elvers (initial body weight (BW) = 3 g) were raised in triplicate for 60 days in a biofloc system (BFT) at 21 °C. Data from the current first study evaluating this farming technology indicated that European eel elvers adapted well to BFT systems as data on growth performance (specific growth rate = 1.48% ± 0.

Metapopulation Structure of Two Species of Pikeworm (, Cestoda) Parasitizing the Postglacial Fish Community in an Oligotrophic Lake.

In the present study, we estimated the levels of infestation of the main fish species that are hosts for two species: and . The prevalence of and infestations in the intestine of their definitive host-pike was similar (71.0% and 77.

The potential of a combination of pungent spices as a novel supplement in gilthead seabream () diets to aid in the strategic use of fish oil in aquafeeds: a holistic perspective.

This work studied the potential of a combination of pungent spices (capsicum, black pepper, ginger, and cinnamaldehyde) to be used as a supplement in diets of gilthead seabream (; 44.1 ± 4.2 g).

Multipathogen infections and multifactorial pathogenesis involved in noble pen shell () mass mortality events: Background and current pathologic approaches.

Disease outbreaks in several ecologically or commercially important invertebrate marine species have been reported in recent years all over the world. Mass mortality events (MMEs) have affected the noble pen shell (), causing its near extinction. Our knowledge of the dynamics of diseases affecting this species is still unclear.

Modulation of gut microbiota and intestinal immune response in gilthead seabream () by dietary bile salt supplementation.

Given their role in lipid digestion, feed supplementation with bile salts could be an economic and sustainable solution to alterations in adiposity and intestinal inflammation generated by some strategies currently used in aquaculture. An important part of the metabolism of bile salts takes place in the intestine, where the microbiota transforms them into more toxic forms. Consequently, we aimed to evaluate the gut immune response and microbial populations in gilthead seabream () fed a diet supplemented with a blend of bile salts with proven background as a regulator of lipid metabolism and fat content.

Trophic diversification and parasitic invasion as ecological niche modulators for gut microbiota of whitefish.

Introduction: The impact of parasites on gut microbiota of the host is well documented, but the role of the relationship between the parasite and the host in the formation of the microbiota is poorly understood. This study has focused on the influence that trophic behavior and resulting parasitism has on the structure of the microbiome.

Methods: Using 16S amplicon sequencing and newly developed methodological approaches, we characterize the gut microbiota of the sympatric pair of whitefish complex and the associated microbiota of cestodes parasitizing their intestine.

Evaluating the Functional Properties of Spray-Dried Porcine Plasma in Gilthead Seabream () Fed Low Fish Meal Diets.

Blood by-products are an untapped source of high-quality ingredients for aquafeeds, containing a broad variety of cytokines, hormones, growth factors, proteins, bioactive peptides, and amino acids. The effects of the spray-dried porcine plasma (SDPP), a type of processed animal protein on several immune parameters, were evaluated in sea bream using ex vivo and in vitro assays. In this study, fish were fed with two isoproteic, isolipidic, and isoenergetic diets: control diet (7% fish meal, FM) and SDPP diet (2% FM and 5% SDPP).

Identification of New CTX Analogues in Fish from the Madeira and Selvagens Archipelagos by Neuro-2a CBA and LC-HRMS.

Ciguatera Poisoning (CP) is caused by consumption of fish or invertebrates contaminated with ciguatoxins (CTXs). Presently CP is a public concern in some temperate regions, such as Macaronesia (North-Eastern Atlantic Ocean). Toxicity analysis was performed to characterize the fish species that can accumulate CTXs and improve understanding of the ciguatera risk in this area.

Electrochemical biosensor for the dual detection of Gambierdiscus australes and Gambierdiscus excentricus in field samples. First report of G. excentricus in the Balearic Islands.

Several genera of marine dinoflagellates are known to produce bioactive compounds that affect human health. Among them, Gambierdiscus and Fukuyoa stand out for their ability to produce several toxins, including the potent neurotoxic ciguatoxins (CTXs), which accumulate through the food web. Once fishes contaminated with CTXs are ingested by humans, it can result in an intoxication named ciguatera.

Porcine Protein Hydrolysates (PEPTEIVA) Promote Growth and Enhance Systemic Immunity in Gilthead Sea Bream ().

The effects of porcine plasma protein hydrolysate (PPH) on growth, feed efficiency, and immune responses was evaluated in . Fish were fed two isoproteic (48% protein), isolipidic (17% fat), and isoenergetic diets (21.7 MJ/kg) diets, one of them containing 5% PPH at the expense of fishmeal.

Parasitic copepods Caligus lacustris (Copepoda: Caligidae) on the rainbow trout Oncorhynchus mykiss in cage aquaculture: morphology, population demography, and first insights into phylogenetic relationships.

Herein, data on rainbow trout infections with the copepod Caligus lacustris in cage aquaculture on Lake Ladoga is presented. Caligus lacustris (n = 127 ex.) were collected from a farm in Lake Ladoga housing cage-reared rainbow trout to describe the size-age and sex structure of the copepod population.

Capacity of the potentially toxic diatoms Pseudo-nitzschia mannii and Pseudo-nitzschia hasleana to tolerate polycyclic aromatic hydrocarbons.

This study investigates the effects of polycyclic aromatic hydrocarbons (PAHs) on two potentially toxic Pseudo-nitzschia hasleana and P. mannii, isolated from a PAH contaminated marine environment. Both species, maintained in non-axenic cultures, have been exposed during 144 h to increasing concentrations of a 15 PAHs mixture.

Skin Multi-Omics-Based Interactome Analysis: Integrating the Tissue and Mucus Exuded Layer for a Comprehensive Understanding of the Teleost Mucosa Functionality as Model of Study.

From a general structural perspective, a mucosal tissue is constituted by two main matrices: the tissue and the secreted mucus. Jointly, they fulfill a wide range of functions including the protection of the epithelial layer. In this study, we simultaneously analyzed the epithelial tissue and the secreted mucus response using a holistic interactome-based multi-omics approach.

The Digestive Function of Early Juveniles Is Differentially Modulated by Dietary Protein, Lipid and Carbohydrate Content and Their Ratios.

is an Amazonian catfish highly appreciated for its high flesh quality, size, and commercial value. Its aquaculture is pursued to satisfy the demands of an increasing population in the region. However, knowledge of the nutritional needs during the early life stages is necessary for improving growth and reducing the incidence of cannibalism, factors that limit the success of its commercial farming.

Pinna nobilis in suboptimal environments are more tolerant to disease but more vulnerable to severe weather phenomena.

We examined a disease outbreak of the fan mussel, Pinna nobilis (L.), in the Alfacs Bay (South Ebro Delta, Spain) during a period of two years in three zones exposed to a summer salinity gradient resulting from agricultural freshwater discharges and distance to the open sea. Long-term monitoring was also conducted in Fangar Bay (North Ebro Delta), featuring lower salinities and no evidence of disease.

Gambierdiscus and Fukuyoa as potential indicators of ciguatera risk in the Balearic Islands.

Gambierdiscus and Fukuyoa are genera of toxic dinoflagellates which were mainly considered as endemic to marine intertropical areas, and that are well known as producers of ciguatoxins (CTXs) and maitotoxins (MTXs). Ciguatera poisoning (CP) is a human poisoning occurring after the consumption of fish or more rarely, shellfish containing CTXs. The presence of these microalgae in a coastal area is an indication of potential risk of CP.